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[vsnet-grb-info 36152] Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38178 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB DATE: 24/11/12 16:43:36 GMT FROM: Ava Myers at NASA GSFC <ava.myers(a)nasa.gov> A. Myers (NPP/GSFC) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 752995908/241111230 (GRB 241111A, GCN [38159](https://gcn.nasa.gov/circulars/38159?query=241111230&startDate=&endD…) at 05:31:43.08 UT on 11 November 2024, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to local particles." View this GCN Circular online at https://gcn.nasa.gov/circulars/38178. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36151] Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38178 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB DATE: 24/11/12 16:43:36 GMT FROM: Ava Myers at NASA GSFC <ava.myers(a)nasa.gov> A. Myers (NPP/GSFC) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 752995908/241111230 (GRB 241111A, GCN [38159](https://gcn.nasa.gov/circulars/38159?query=241111230&startDate=&endD…) at 05:31:43.08 UT on 11 November 2024, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to local particles." View this GCN Circular online at https://gcn.nasa.gov/circulars/38178. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36150] GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38177 SUBJECT: GRB 241107A: Swift/BAT candidate arcminute localization of a short burst DATE: 24/11/12 16:15:55 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 241107A onboard (T0: 2024-11-07T23:30:00.1 UTC, SVOM/GRM GCN 38125). 3 seconds of TTE data is available covering the time of this burst, associated with BAT failed trigger #1266248, as the burst triggered BAT's rate trigger algorithm, but failed to localize the burst onboard. There is no long duration GUANO data available for this burst due to lack of prompt notice from other instruments. The burst is seen clearly in the BAT rates light-curve, but we fail to recover it in an image. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), typically requires ~40 s of off-time TTE data to properly fit the background, but here we attempt to approximate the background model with ~2.5 s of TTE data around the burst. NITRATES detects the burst in a 0.2 s analysis time bin with a sqrt(TS) of 35.2. An arcminute localization candidate is found with a DeltaLLHPeak of 10.3 and DeltaLLHOut of 2.5. Due to limited data, nonstandard fitting was used, so the position is independently not highly confident, but matches both the IPN (GCN 38165) and INTEGRAL/IBIS (GCN 38172) localizations. See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. The BAT candidate position is RA, Dec = 111.325, -24.487 deg which is RA(J2000) = 07h 25m 18.0s Dec(J2000) = -24 29′ 13.2″ with an estimated uncertainty of 4 arcmin radius. View this GCN Circular online at https://gcn.nasa.gov/circulars/38177. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36148] GRB 241112B: Mephisto optical upper limits
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38176 SUBJECT: GRB 241112B: Mephisto optical upper limits DATE: 24/11/12 14:52:04 GMT FROM: Brajesh Kumar at SWIFAR, YNU <brajesh(a)ynu.edu.cn> Guowang Du (SWIFAR, YNU), Weikang Lin (SWIFAR, YNU), Brajesh Kumar (SWIFAR, YNU), Yaosong Yu (SWIFAR, YNU), Yehao Cheng (SWIFAR, YNU), Xinlei Chen (SWIFAR, YNU), Yu Pan (SWIFAR, YNU), Xingzhu Zou (SWIFAR, YNU), Jinghua Zhang (SWIFAR, YNU), Yuanpei Yang (SWIFAR, YNU), Yuan Fang (SWIFAR, YNU), Xuhui Han (NAOC), Pinpin Zhang (NAOC), Liping Xin (NAOC), Chao Wu (NAOC), Xiangkun Liu (SWIFAR, YNU), Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team: The 1.6m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University located at Lijiang Observatory was triggered to observe GRB 241112B (sb24111201) detected by SVOM/ECLAIRs and SVOM/GRM (Yang et al., GCN 38173). The observations were started at 11:46:00 (UT) 2024-11-12 (~0.8 hr after SVOM trigger) and multiple frames were obtained in uvgriz bands. No new candidate was detected in the stacked images, consistent with Kumar et al. (GCN 38175). The 3-sigma upper limits are the following: Mid-Time(UT) Band Exp(s) Lim-mag(AB) 2024-11-12T11:50:43 u 180*3 >21.21 2024-11-12T12:01:14 v 180*3 >21.50 2024-11-12T11:50:40 g 50*9 >21.84 2024-11-12T12:01:12 r 50*9 >22.10 2024-11-12T11:49:55 i 79*5 >21.16 2024-11-12T12:01:16 z 79*6 >20.47 -------------------------------------------------------------------------- Mephisto (Multi-channel Photometric Survey Telescope) is a 1.6m wide-field multi-channel telescope, the first of its type in the world, capable of imaging the same field of view in three optical bands simultaneously. It provides real-time, high-quality colors of stellar objects. The on-site telescope assemblage and commissioning were carried out in September 2022. The first light in all three channels was achieved on 2023 December 21. -------------------------------------------------------------------------- View this GCN Circular online at https://gcn.nasa.gov/circulars/38176. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36149] GRB 241112B: Mephisto optical upper limits
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38176 SUBJECT: GRB 241112B: Mephisto optical upper limits DATE: 24/11/12 14:52:04 GMT FROM: Brajesh Kumar at SWIFAR, YNU <brajesh(a)ynu.edu.cn> Guowang Du (SWIFAR, YNU), Weikang Lin (SWIFAR, YNU), Brajesh Kumar (SWIFAR, YNU), Yaosong Yu (SWIFAR, YNU), Yehao Cheng (SWIFAR, YNU), Xinlei Chen (SWIFAR, YNU), Yu Pan (SWIFAR, YNU), Xingzhu Zou (SWIFAR, YNU), Jinghua Zhang (SWIFAR, YNU), Yuanpei Yang (SWIFAR, YNU), Yuan Fang (SWIFAR, YNU), Xuhui Han (NAOC), Pinpin Zhang (NAOC), Liping Xin (NAOC), Chao Wu (NAOC), Xiangkun Liu (SWIFAR, YNU), Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team: The 1.6m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University located at Lijiang Observatory was triggered to observe GRB 241112B (sb24111201) detected by SVOM/ECLAIRs and SVOM/GRM (Yang et al., GCN 38173). The observations were started at 11:46:00 (UT) 2024-11-12 (~0.8 hr after SVOM trigger) and multiple frames were obtained in uvgriz bands. No new candidate was detected in the stacked images, consistent with Kumar et al. (GCN 38175). The 3-sigma upper limits are the following: Mid-Time(UT) Band Exp(s) Lim-mag(AB) 2024-11-12T11:50:43 u 180*3 >21.21 2024-11-12T12:01:14 v 180*3 >21.50 2024-11-12T11:50:40 g 50*9 >21.84 2024-11-12T12:01:12 r 50*9 >22.10 2024-11-12T11:49:55 i 79*5 >21.16 2024-11-12T12:01:16 z 79*6 >20.47 -------------------------------------------------------------------------- Mephisto (Multi-channel Photometric Survey Telescope) is a 1.6m wide-field multi-channel telescope, the first of its type in the world, capable of imaging the same field of view in three optical bands simultaneously. It provides real-time, high-quality colors of stellar objects. The on-site telescope assemblage and commissioning were carried out in September 2022. The first light in all three channels was achieved on 2023 December 21. -------------------------------------------------------------------------- View this GCN Circular online at https://gcn.nasa.gov/circulars/38176. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36147] GRB 241112B: GOTO optical upper limits
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38175 SUBJECT: GRB 241112B: GOTO optical upper limits DATE: 24/11/12 14:02:37 GMT FROM: Amit Kundu at Royal Holloway - U. of London, UK <amitkundu515(a)gmail.com> A. Kumar, K. Ulaczyk, D. O'Neill, G. Ramsay, B. Godson, B. P. Gompertz, R. Starling, K. Ackley, M. J. Dyer, J. Lyman, F. Jimenez-Ibarra, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle and D. Pollacco report on behalf of the GOTO collaboration: The Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022, Dyer et al. 2024) observed the field of SVOM/ECLAIRs detected GRB 241112B (Yang et al., GCN 38173) at 12:35:35 UT on 2024-11-12 (around 1.637 hours post trigger). The observation was taken by GOTO-S (at Siding Spring Observatory in Australia), and consisted of 3x60s exposures in the GOTO L-band (400-700 nm). Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using deeper template observations of the same pointings. No new optical source within the SVOM/ECLAIRs localisation region is identified to a 3-sigma limiting magnitude of L > 19.1. The shallower upper limit results from the moon's lower angle relative to the source field. Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction. GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC). View this GCN Circular online at https://gcn.nasa.gov/circulars/38175. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36146] GRB 241112B: Swift ToO observations
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38174 SUBJECT: GRB 241112B: Swift ToO observations DATE: 24/11/12 13:58:16 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the SVOM/ECLAIRs GRB 241112B. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021730 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the SVOM/ECLAIRs event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38174. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36145] GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38173 SUBJECT: GRB 241112B : detection of a long GRB by SVOM/ECLAIRs DATE: 24/11/12 11:28:07 GMT FROM: Stéphane Schanne at CEA Paris-Saclay/IRFU <s.schanne(a)cea.fr> SVOM/ECLAIRs Commissioning Team: Hui Yang, Marius Brunet, Jean-Luc Atteia, Laurent Bouchet, Sebastien Guillot, Juliette Alaux (IRAP), Stéphane Schanne, Frédéric Chateau, Nicolas Dagoneau, Hervé Le Provost (CEA), Wenjin Xie, Donhua Zhao (NAOC), Tais Maiolino (LUPM), Floriane Cangemi (APC), Karine Mercier, Marie-Claire Charmeau, Stefano Crepaldi (CNES) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Olivier Godet (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV) Report on behalf of the SVOM team: During the commissioning phase, the SVOM/ECLAIRs telescope triggered and located the long GRB 241112B (sb24111201) at 2024-11-12T10:57:21 UT (Tb), which was also detected by SVOM/GRM. The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by both the on-board Count-Rate Trigger (CRT) and Image Trigger (IMT) and 19 alerts were received. The best detection is obtained by CRT with a signal-to-noise ratio of 23.1 in the 8-50 keV energy band over a time window of 10.24 s starting at Tb. The light-curve shows two main peaks of about 10 s duration each, the first is mainly seen below 50 keV, the second below 20 keV. The GRB localization is RA, Dec = 29.055, 9.146 (J2000). The statistical uncertainty on this position is 3.7 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature. SVOM performed an automatic slew to the burst. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES, and IRAP. The SVOM point of contact for this burst is: stephane.schanne AT cea.fr View this GCN Circular online at https://gcn.nasa.gov/circulars/38173. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36144] GRB 241107A: INTEGRAL IBIS localization
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38172 SUBJECT: GRB 241107A: INTEGRAL IBIS localization DATE: 24/11/12 10:41:26 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti(a)inaf.it> S.Mereghetti, D.P.Pacholski (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: The burst GRB 241107A, detected by SVOM/GBM (Wang et al. GCN Circ. 38125), INTEGRAL/IBIS-PICsIT (Rodi et al., GCN 38164), Swift/BAT, Konus-Wind and INTEGRAL/SPI-ACS (Kozyrev et al., GCN Circ. 38165) was located in the coded field of view of the IBIS instrument, but it was too faint to trigger IBAS. The burst was detected in the IBIS/ISGRI data at 23:30:00.2 UT of November 7, 2024 A preliminary analysis indicates a duration of about 0.2 s, a fluence of about 3e-8 erg/cm2 (20-200 keV) and the following coordinates (J2000): R.A.= 111.312 deg DEC.= -24.496 deg with an uncertainty of 5 arcmin (90% c.l.). View this GCN Circular online at https://gcn.nasa.gov/circulars/38172. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36143] EP241107a: EP-FXT follow-up observations
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38171 SUBJECT: EP241107a: EP-FXT follow-up observations DATE: 24/11/12 05:08:32 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> R.-Z. Li (YNAO, CAS), W. Chen (NAO, CAS), K. Chatterjee, X. L. Chen (YNU), H. Zhou (PMO, CAS), T. Zhao and H. W. Pan (NAO, CAS) report on behalf of the Einstein Probe team: We report the EP-FXT follow-up observations of the X-ray transient, EP241107a, which triggered the on-board EP-WXT processing unit at 2024-11-07T14:10:23Z (UTC) (Zhou et al., GCN 38112). The refined peak flux is estimated to be approximately 4.2E-9 erg/s/cm^2 in 0.5-4 keV. There are three follow-up observations of EP241107a, detecting a fading, previously uncataloged X-ray source. The results are reported: |T_start (UTC) | T_end (UTC) | Exposure (s) | T_mid - T_0 (h) | Flux (0.5-10keV, erg/s/cm^2)| | ------------ | ------------ | ------------ | ------------ | ------------ | |2024-11-07T14:12:16 | 2024-11-07T16:09:18 | 4321 | 1.0 | ~ 1.47E-11| |2024-11-08T00:54:51 | 2024-11-08T03:22:18 | 4007 | 12.0 | ~ 4.35E-13| |2024-11-11T10:37:41 | 2024-11-11T14:40:47 | 9104 | 94.5 | < 2.23E-14| Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/38171. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36142] GRB 241112A: Fermi GBM Final Real-time Localization
by GCN Circulars 12 Nov '24

12 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38170 SUBJECT: GRB 241112A: Fermi GBM Final Real-time Localization DATE: 24/11/12 02:00:12 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely SHORT GRB At 01:49:39 UT on 12 Nov 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241112A (trigger 753068984.626592 / 241112076). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 154.7, Dec = -0.8 (J2000 degrees, equivalent to J2000 10h 18m, 0d 48'), with a statistical uncertainty of 13.8 degrees. The angle from the Fermi LAT boresight is 82.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241112076/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241112076/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241112076/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38170. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36141] LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38169 SUBJECT: LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume DATE: 24/11/11 17:59:40 GMT FROM: David Cook at Caltech/IPAC-NED <dcook(a)ipac.caltech.edu> David O. Cook (Caltech/IPAC), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), Joseph M. Mazzarella (Caltech/IPAC), Marion Schmitz (Caltech/IPAC), and Leo Singer (NASA/GSFC) On behalf of the NASA/IPAC Extragalactic Database (NED) Team. We spatially cross-matched the LVK S241110br-4-Update sky localization with the NED Local Volume Sample (NED-LVS; Cook et al. 2023), which is a subset of NED with a redshift or redshift-independent distance less than 1000 Mpc. We find 5829 galaxies within the 90% containment volume, and we list here the top 20 galaxies sorted by the joint probability of the 3D localization and the WISE W1 luminosity (an observable proxy for stellar mass). For the full or top 20 list of galaxies in the 90% volume go either to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/ or click on the following links: Full List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S241110br/4 Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S241110br/4/20 The NED-GWF service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic follow-up observations. The NED top 20 list is sorted by the joint probability of the 3D localization and the WISE W1 luminosity, but users can sort on additional pre-computed prioritization metrics (star formation rate, P_3D * P_SFR; and specific star formation rate, P_3D * P_sSFR; etc.) which are available via downloading the entire galaxy list inside the event's probability volume. | objname| ra| dec|objtype| DistMpc|DistMpc_unc| m_NUV| m_NUV_unc| m_Ks| m_Ks_unc| m_W1| m_W1_unc| P_3D|P_3D_LumW1| |-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------| |WISEA J131116.29-311253.8| 197.81796| -31.21503| G| 779.34| 0.65| null| null| 12.862| 0.179| 9.520| 0.006|4.62e-08| 8.00e-10| |WISEA J132749.49-403006.7| 201.95621| -40.50194| G| 614.55| null| null| null| 13.291| 0.167| 10.181| 0.006|1.25e-07| 7.36e-10| |WISEA J133326.27-330144.1| 203.35950| -33.02894| G| 495.09| null| null| null| 13.159| 0.157| 9.997| 0.006|1.55e-07| 6.95e-10| |WISEA J131452.54-354321.6| 198.71896| -35.72267| G| 927.19| 0.65| null| null| 12.108| 0.043| 10.554| 0.022|7.32e-08| 6.90e-10| |WISEA J133315.93-370313.9| 203.31629| -37.05392| G| 813.61| null| null| null| 12.959| 0.108| 11.639| 0.023|2.20e-07| 5.89e-10| |WISEA J132657.03-400119.7| 201.73758| -40.02206| G| 800.66| 0.44| null| null| 12.842| 0.136| 11.439| 0.006|1.73e-07| 5.41e-10| |WISEA J133507.74-394446.9| 203.78229| -39.74636| G| 577.98| null| null| null| 12.604| 0.137| 10.527| 0.006|1.30e-07| 4.90e-10| |WISEA J132344.22-321719.2| 200.93425| -32.28869| G| 690.48| null| null| null| 13.780| 0.212| 11.694| 0.007|2.25e-07| 4.12e-10| |WISEA J132125.36-340947.9| 200.35563| -34.16336| G| 674.85| 0.65| null| null| 12.157| 0.093| 11.913| 0.010|2.75e-07| 3.94e-10| |WISEA J131835.92-322812.2| 199.64958| -32.47011| G| 645.49| 0.65| null| null| 12.989| 0.156| 11.431| 0.008|1.87e-07| 3.81e-10| |WISEA J133232.33-393736.1| 203.13475| -39.62667| G| 790.30| null| null| null| 13.027| 0.137| 11.937| 0.009|1.91e-07| 3.68e-10| |WISEA J132812.28-382712.3| 202.05138| -38.45353| G| 795.80| null| null| null| 13.439| 0.199| 12.352| 0.014|2.74e-07| 3.65e-10| |WISEA J131802.49-303433.5| 199.51046| -30.57592| G| 609.35| null| null| null| 13.128| 0.158| 11.050| 0.006|1.37e-07| 3.54e-10| |WISEA J132239.19-363113.4| 200.66338| -36.52044| G| 714.13| null| null| null| 13.267| 0.147| 12.488| 0.009|3.74e-07| 3.53e-10| |WISEA J133054.64-354926.0| 202.72775| -35.82397| G| 638.11| 0.79| null| null| 12.784| 0.126| 12.340| 0.012|3.99e-07| 3.44e-10| |WISEA J132734.27-354548.2| 201.89275| -35.76347| G| 733.20| null| null| null| 13.569| 0.204| 12.765| 0.016|4.33e-07| 3.34e-10| | FGCE 1045| 199.62833| -31.04486| G| 505.00| null| null| null| 12.937| 0.126| 10.851| 0.006|1.49e-07| 3.18e-10| |WISEA J132656.75-352823.7| 201.73654| -35.47325| G| 672.33| 0.65| null| null| 13.565| 0.102| 12.626| 0.024|4.31e-07| 3.18e-10| |WISEA J132151.31-344029.1| 200.46367| -34.67475| G| 663.09| 0.49| null| null| 12.557| 0.094| 12.350| 0.013|3.01e-07| 2.78e-10| |WISEA J133012.65-351740.7| 202.55275| -35.29467| G| 551.66| null| 20.176| 0.129| 13.586| 0.204| 11.994| 0.007|3.06e-07| 2.71e-10| Table 1: Top 20 galaxies in NED-LVS that fall in the 90% probability volume for S241110br sorted by the joint probability of 3D position and WISE W1 luminosity (P_3D * P_LumW1). Galaxy is the NED preferred name. RA and Dec are the Equatorial coordinates in degrees (J2000). Objtype is the object type of the galaxy candidate. Distance is the distance to the galaxy in Mpc. m_NUV and mErr_NUV are the apparent magnitude and error from GALEX. m_Ks and mErr_Ks are the apparent magnitude and error from 2MASS. m_W1 and mErr_W1 are the apparent magnitude and error from AllWISE. P_3D is the probability that the galaxy is in the volume given the distance of GW event. P_3D_LumW1 is the joint probability within the volume weighted by the WISE1 luminosity of the galaxy (P_3D * P_LumW1). View this GCN Circular online at https://gcn.nasa.gov/circulars/38169. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36140] LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38168 SUBJECT: LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt DATE: 24/11/11 17:51:56 GMT FROM: James Gillanders at University of Oxford <jhgillanders.astro(a)gmail.com> J. H. Gillanders (Oxford), K. W. Smith, S. J. Smartt (Oxford/QUB), D. R. Young, M. Nicholl, M. Fulton, M. McCollum, T. Moore, J. Weston, X. Sheng, A. Aamer, C. R. Angus, D. Magill (QUB), P. Ramsden (QUB/Birmingham), L. Shingles (GSI/QUB), S. Srivastav, H. Stevance, A. J. Cooper, F. Stoppa (Oxford), L. Rhodes (TSI/McGill), L. Denneau, J. Tonry, H. Weiland, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), A. Jordan, V. Suc (UAI, Obstech), A. Rest (STScI), T.-W. Chen (NCU), C. Stubbs (Harvard), J. Sommer (LMU) and B. P. Schmidt (ANU). We report observations of the skymap of the possible NSBH merger event S241109bn (LVK Collaborations, GCN 38142) with the ATLAS survey (Tonry et al., 2018, PASP, 13, 164505). ATLAS scans the visible night sky every 24-48 hours with a 4x30s tiling pattern, reaching typical limiting magnitudes, m~19.5 (AB mag) in 30 seconds. Our standard observing strategy tiled 31.7% of the 90% bilby.fits sky localisation area within 24 hours of the GW trigger. This rose to 35.7% within 72 hours. The images were processed with the ATLAS pipeline, and reference images were subtracted. Transient candidates were identified and run through our standard filtering procedures (Smith et al., 2020, PASP, 132, 1). All potential transients that passed our data processing cuts were manually inspected, and cross-matched with catalogued galaxies and stars. We do not find any compelling candidates that lie within the skymap, occurred after the GW trigger time, and are matched with galaxies in the range 0.10 < z < 0.17 (D = 600 +/- 150 Mpc; LVK Collaborations, GCN 38149), to a limit of around m_o~19.5 (AB mag). We identity one bright transient discovered in images taken 1.57 days after the GW trigger (MJD 60623.50) and registered as AT2024aawt on the IAU Astronomical Transient Name Server (Tonry et al., TNS Astronomical Transient Report No. 232251). We detected the transient at MJD 60625.07 == 2024-11-11 01:40 UTC, at the coordinate location of RA=314.464552727, Dec=-41.64411. Its location is not coincident with any known, catalogued source, although some faint excess is visible in the public DECaLS image of the field. AT2024aawt was discovered with an o-band magnitude, m_o = 17.28 +/- 0.08 (AB mag). Our most recent previous observation at the transient location was on MJD 60624.04 (0.54 days after GW trigger), from which we extracted a 3-sigma limiting magnitude, m_o = 19.50 (AB mag). Forced photometry at the transient location indicates no significant activity for the last 30 days. This is most likely a foreground, Galactic source (such as a dwarf nova in outburst), and thus not related to the GW event, but a spectrum should be taken to confirm. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for Near-Earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; by-products of this search include images and catalogues from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112, HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii’s Institute for Astronomy, Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile. View this GCN Circular online at https://gcn.nasa.gov/circulars/38168. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36139] GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38167 SUBJECT: GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681 DATE: 24/11/11 14:28:48 GMT FROM: Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo(a)ucd.ie> L. Izzo (INAF-OACn & DARK/NBI), A. A. Chrimes (ESA/ESTEC & Radboud Univ.), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Saccardi (CEA/Irfu), A. Martin-Carrillo (UCD), A. J. Levan (Radboud Univ. and Warwick Univ.), B. P. Gompertz (Birmingham), N. R. Tanvir (U. Leicester), J. T. Palmerio (CEA/Irfu), report on behalf of the Stargate collaboration: Using the most updated calibration files, we have produced an improved reduction of the VLT/FORS2 afterglow spectrum (Izzo et al., GCN 38097) of GRB 241105A (Fermi GBM Team, GCN 38085; Yulakanti et al., GCN 38088). Compared to our preliminary version based on archival calibrations, we have found a slight discrepancy in the wavelength solution. Based on the same features already discussed in our previous GCN 38097, the refined redshift we measure for GRB 241105A is z = 2.681. This change implies a modest reduction of ~1% and ~2% in the Eiso and Liso values reported by Frederiks et al. (GCN 38103) and Pathak et al. (GCN 38104). View this GCN Circular online at https://gcn.nasa.gov/circulars/38167. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36138] LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38166 SUBJECT: LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate DATE: 24/11/11 11:47:18 GMT FROM: Pawan Tiwari at Gran Sasso Science Institute, Italy <pawan.tiwari(a)gssi.it> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241111bn during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2024-11-11 11:15:52.570 UTC (GPS time: 1415358970.570). The candidate was found by the cWB [1], cWB BBH [2], GstLAL [3], MBTA [4], and PyCBC Live [5] analysis pipelines. S241111bn is an event of interest because its false alarm rate, as estimated by the online analysis, is 7.1e-30 Hz, or about one in 1e22 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241111bn After parameter estimation by RapidPE-RIFT [6], the classification of the GW signal, in order of descending probability, is BBH (>99%), NSBH (<1%), BNS (<1%), or Terrestrial (<1%). Low-frequency excess of noise was present in LIGO Livingston detector at the time of the event, which may affect the sky-localization of the candidate. Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [7] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [7] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is <1%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [8], distributed via GCN notice about 23 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [8], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 472 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1401 +/- 367 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Klimenko et al. PRD 93, 042004 (2016) doi:10.1103/PhysRevD.93.042004 [2] T. Mishra et al. PRD 105, 083018 (2022) doi:10.1103/PhysRevD.105.083018 [3] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [4] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 [5] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a [6] Rose et al. (2022) arXiv:2201.05263 and Pankow et al. PRD 92, 023002 (2015) doi:10.1103/PhysRevD.92.023002 [7] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [8] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38166. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36137] IPN triangulation of GRB 241107A (short/hard)
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38165 SUBJECT: IPN triangulation of GRB 241107A (short/hard) DATE: 24/11/11 11:39:25 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, Y. Zhang, C. Wang, S. Xiong, J. Wei, and B. Cordier on behalf of the SVOM-GRM team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr, and A.S. Gardner on on behalf of the GRS-Odyssey GRB team, report: The hard-spectrum, short-duration GRB 241107A (SVOM-GRM detection: Wang et al., GCN 38125; INTEGRAL-IBIS/PICsIT detection: Rodi et al., GCN 38164) was detected by SVOM (GRM), Konus-Wind, INTEGRAL (SPI-ACS), and Swift (BAT) at about 84600 s UT (23:30:00). The burst was inside the coded field of view of the BAT, but there was no BAT trigger. We have triangulated it to a preliminary, 3 sigma error box, whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 113.377 (07h 33m 30s) -22.582 (-22d 34' 56") Corners: 107.205 (07h 08m 49s) -27.689 (-27d 41' 21") 114.251 (07h 37m 00s) -21.868 (-21d 52' 04") 117.499 (07h 50m 00s) -18.325 (-18d 19' 30") 112.449 (07h 29m 48s) -23.318 (-23d 19' 03") --------------------------------------------- The error box area is 1.13 sq. deg, and its maximum dimension is 13.3 deg (the minimum one is 9 arcmin). The Sun distance was 100 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB241107_T84602/IPN/ The HEALPix triangulation maps are in units of probability density. The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/38165. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36136] GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38164 SUBJECT: GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst DATE: 24/11/11 11:19:42 GMT FROM: James Rodi at IAPS-INAF <james.rodi(a)inaf.it> J. Rodi, P. Ubertini, A. Bazzano, and L. Natalucci - INAF-IAPS We report on the INTEGRAL/IBIS/PICsIT detection of GRB 241107A first reported by SVOM/GRB (Wang et al. GCN 38125). In the 200-2600 keV energy range, the burst duration is ~0.16 s with a total significance of ~34.4 sigma. The significance in each of the 8 energy channels ranges from ~7.5 - 10 sigma. Further detailed analysis is ongoing. View this GCN Circular online at https://gcn.nasa.gov/circulars/38164. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36135] GRB 241025C: VZLUSAT-2 detection
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38163 SUBJECT: GRB 241025C: VZLUSAT-2 detection DATE: 24/11/11 10:34:54 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration. The short-duration GRB 241025C (Fermi/GBM detection: GCN 37887; Konus/Wind detection at 2024-10-25 15:36:11.902 UTC) was detected by the GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/). The data acquisition was performed by the GRB detector unit no. 1. The detection was confirmed at the peak time 2024-10-25 15:36:09 UTC. The T90 duration is 2 s and the significance during T90 reaches 7.9 sigma. The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB241025C_GCN_VZLUSAT2.pdf All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/ The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral. View this GCN Circular online at https://gcn.nasa.gov/circulars/38163. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36134] GRB 241025A: VZLUSAT-2 detection
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38162 SUBJECT: GRB 241025A: VZLUSAT-2 detection DATE: 24/11/11 10:34:18 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration. The long-duration GRB 241025A (Fermi/GBM detection: GCN 37886; Swift/BAT detection: GCN 37859; SVOM/GRM detection: GCN 37863; EP detection: GCN 37864; Konus/Wind detection: GCN 37927) was detected by the GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/). The data acquisition was performed by the GRB detector unit no. 1. The detection was confirmed at the peak time 2024-10-25 01:36:50 UTC. The T90 duration is 63 s and the significance during T90 reaches 10 sigma. The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB241025A_GCN_VZLUSAT2.pdf All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/ The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral. View this GCN Circular online at https://gcn.nasa.gov/circulars/38162. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36133] GRB 241018A: cubesat Avion detection
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38161 SUBJECT: GRB 241018A: cubesat Avion detection DATE: 24/11/11 09:51:18 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> A. Bogomolov, V. Bogomolov, A. Iyudin, S. Svertilov, N. Vasil’ev on behalf of the MSU “Sozvezdie-270” team, report: At 2024-10-18 11:54:37 UT the long-duration GRB 241018A (SVOM detection: GCN #37812; Konus-Wind detection: GCN #37832) was detected by the cubesat Avion of the Moscow University project “Constellation-270” [1]. Total amount of photons detected by Avion in the energy band 40-500 keV is 234, it corresponds to a fluence of 1*10^(-6) erg/cm^2. The LC in the energy band 40-500 keV has two main peaks with maximal flux 7.4phot/(cm^2*s) in the 1st peak and 8.4 phot/(cm^2*s) in the 2nd peak. Total duration (T90) of the burst is 7 s. The light curve obtained by Avion is available here: https://swx.sinp.msu.ru/models/grb_cat/data/pictures/GRB_241018A_Avion_DeCo… Parameters of GRB 241018A as well as 20 other GRBs detected by Moscow University cubesats are listed at: https://swx.sinp.msu.ru/models/grb_cat/grb.php?lang=en Avion is one of 5 cubesats of the Lomonosov MSU project “Constellation-270” [1] launched on 2023 June 27. The payload of Avion is a set of scintillation gamma-ray detectors DeCoR [2], the energy range is >30 keV, the time resolution is 0.5s. [1] Svertilov et al. 2023 https://link.springer.com/chapter/10.1007/978-3-031-50248-4_21 [2] Bogomolov et al. 2022 Universe 8, 282 https://www.mdpi.com/2218-1997/8/5/282 View this GCN Circular online at https://gcn.nasa.gov/circulars/38161. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36132] Fermi trigger No 752990530: Global MASTER-Net observations report
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38160 SUBJECT: Fermi trigger No 752990530: Global MASTER-Net observations report DATE: 24/11/11 09:31:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB241111.17 (trigger No 752990530,14h 21m 24.00s , -43d 13m 58.8s, R=34.92) errorbox 12593 sec after notice time and 12627 sec after trigger time at 2024-11-11 07:32:32 UT, with upper limit up to 18.0 mag. The observations began at zenith distance = 68 deg. The sun altitude is -22.8 deg. The galactic latitude b = 16 deg., longitude l = 320 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2665525 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 12707 | 2024-11-11 07:32:32 | MASTER-OAFA | (13h 45m 20.02s , -69d 44m 29.6s) | C | 160 | 17.0 | 12658 | 2024-11-11 07:32:33 | MASTER-OAFA | (14h 10m 45.56s , -69d 13m 21.1s) | C | 60 | 18.0 | 12723 | 2024-11-11 07:33:38 | MASTER-OAFA | (14h 10m 45.09s , -69d 13m 18.0s) | C | 60 | 18.0 | 12789 | 2024-11-11 07:34:44 | MASTER-OAFA | (14h 10m 44.71s , -69d 13m 16.0s) | C | 60 | 18.0 | 12919 | 2024-11-11 07:36:04 | MASTER-OAFA | (13h 02m 38.63s , -69d 44m 27.2s) | C | 160 | 17.4 | 12869 | 2024-11-11 07:36:04 | MASTER-OAFA | (13h 28m 06.36s , -69d 13m 24.3s) | C | 60 | 17.9 | 12935 | 2024-11-11 07:37:10 | MASTER-OAFA | (13h 28m 06.08s , -69d 13m 22.3s) | C | 60 | 17.8 | 13000 | 2024-11-11 07:38:15 | MASTER-OAFA | (13h 28m 05.75s , -69d 13m 20.4s) | C | 60 | 17.8 | 13359 | 2024-11-11 07:43:24 | MASTER-OAFA | (13h 45m 12.77s , -69d 45m 04.8s) | C | 160 | 17.2 | 13309 | 2024-11-11 07:43:24 | MASTER-OAFA | (14h 10m 39.62s , -69d 14m 02.3s) | C | 60 | 18.0 | 13375 | 2024-11-11 07:44:30 | MASTER-OAFA | (14h 10m 39.15s , -69d 14m 00.3s) | C | 60 | 18.0 | 13440 | 2024-11-11 07:45:35 | MASTER-OAFA | (14h 10m 38.78s , -69d 13m 58.1s) | C | 60 | 18.0 | 13568 | 2024-11-11 07:46:53 | MASTER-OAFA | (13h 02m 34.31s , -69d 42m 21.9s) | C | 160 | 17.4 | 13518 | 2024-11-11 07:46:53 | MASTER-OAFA | (13h 28m 00.11s , -69d 11m 24.6s) | C | 60 | 17.8 | 13584 | 2024-11-11 07:47:59 | MASTER-OAFA | (13h 27m 59.78s , -69d 11m 22.8s) | C | 60 | 17.8 | 13649 | 2024-11-11 07:49:04 | MASTER-OAFA | (13h 27m 59.40s , -69d 11m 20.9s) | C | 60 | 17.9 | 13729 | 2024-11-11 07:50:24 | MASTER-OAFA | (13h 03m 09.49s , -67d 17m 24.0s) | C | 60 | 17.4 | 13794 | 2024-11-11 07:51:29 | MASTER-OAFA | (13h 03m 09.25s , -67d 17m 22.2s) | C | 60 | 17.4 | 13860 | 2024-11-11 07:52:35 | MASTER-OAFA | (13h 03m 08.93s , -67d 17m 20.5s) | C | 60 | 17.4 | 13989 | 2024-11-11 07:53:54 | MASTER-OAFA | (13h 45m 06.38s , -69d 45m 45.7s) | C | 160 | 17.3 | 13939 | 2024-11-11 07:53:54 | MASTER-OAFA | (14h 10m 34.42s , -69d 14m 48.7s) | C | 60 | 18.0 | 14004 | 2024-11-11 07:54:59 | MASTER-OAFA | (14h 10m 34.00s , -69d 14m 47.3s) | C | 60 | 18.0 | 14070 | 2024-11-11 07:56:05 | MASTER-OAFA | (14h 10m 33.61s , -69d 14m 45.9s) | C | 60 | 18.0 | 14148 | 2024-11-11 07:57:23 | MASTER-OAFA | (13h 28m 02.92s , -69d 12m 43.1s) | C | 60 | 17.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38160. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36131] Fermi trigger No 752990530: Global MASTER-Net observations report
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38160 SUBJECT: Fermi trigger No 752990530: Global MASTER-Net observations report DATE: 24/11/11 09:31:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB241111.17 (trigger No 752990530,14h 21m 24.00s , -43d 13m 58.8s, R=34.92) errorbox 12593 sec after notice time and 12627 sec after trigger time at 2024-11-11 07:32:32 UT, with upper limit up to 18.0 mag. The observations began at zenith distance = 68 deg. The sun altitude is -22.8 deg. The galactic latitude b = 16 deg., longitude l = 320 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2665525 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 12707 | 2024-11-11 07:32:32 | MASTER-OAFA | (13h 45m 20.02s , -69d 44m 29.6s) | C | 160 | 17.0 | 12658 | 2024-11-11 07:32:33 | MASTER-OAFA | (14h 10m 45.56s , -69d 13m 21.1s) | C | 60 | 18.0 | 12723 | 2024-11-11 07:33:38 | MASTER-OAFA | (14h 10m 45.09s , -69d 13m 18.0s) | C | 60 | 18.0 | 12789 | 2024-11-11 07:34:44 | MASTER-OAFA | (14h 10m 44.71s , -69d 13m 16.0s) | C | 60 | 18.0 | 12919 | 2024-11-11 07:36:04 | MASTER-OAFA | (13h 02m 38.63s , -69d 44m 27.2s) | C | 160 | 17.4 | 12869 | 2024-11-11 07:36:04 | MASTER-OAFA | (13h 28m 06.36s , -69d 13m 24.3s) | C | 60 | 17.9 | 12935 | 2024-11-11 07:37:10 | MASTER-OAFA | (13h 28m 06.08s , -69d 13m 22.3s) | C | 60 | 17.8 | 13000 | 2024-11-11 07:38:15 | MASTER-OAFA | (13h 28m 05.75s , -69d 13m 20.4s) | C | 60 | 17.8 | 13359 | 2024-11-11 07:43:24 | MASTER-OAFA | (13h 45m 12.77s , -69d 45m 04.8s) | C | 160 | 17.2 | 13309 | 2024-11-11 07:43:24 | MASTER-OAFA | (14h 10m 39.62s , -69d 14m 02.3s) | C | 60 | 18.0 | 13375 | 2024-11-11 07:44:30 | MASTER-OAFA | (14h 10m 39.15s , -69d 14m 00.3s) | C | 60 | 18.0 | 13440 | 2024-11-11 07:45:35 | MASTER-OAFA | (14h 10m 38.78s , -69d 13m 58.1s) | C | 60 | 18.0 | 13568 | 2024-11-11 07:46:53 | MASTER-OAFA | (13h 02m 34.31s , -69d 42m 21.9s) | C | 160 | 17.4 | 13518 | 2024-11-11 07:46:53 | MASTER-OAFA | (13h 28m 00.11s , -69d 11m 24.6s) | C | 60 | 17.8 | 13584 | 2024-11-11 07:47:59 | MASTER-OAFA | (13h 27m 59.78s , -69d 11m 22.8s) | C | 60 | 17.8 | 13649 | 2024-11-11 07:49:04 | MASTER-OAFA | (13h 27m 59.40s , -69d 11m 20.9s) | C | 60 | 17.9 | 13729 | 2024-11-11 07:50:24 | MASTER-OAFA | (13h 03m 09.49s , -67d 17m 24.0s) | C | 60 | 17.4 | 13794 | 2024-11-11 07:51:29 | MASTER-OAFA | (13h 03m 09.25s , -67d 17m 22.2s) | C | 60 | 17.4 | 13860 | 2024-11-11 07:52:35 | MASTER-OAFA | (13h 03m 08.93s , -67d 17m 20.5s) | C | 60 | 17.4 | 13989 | 2024-11-11 07:53:54 | MASTER-OAFA | (13h 45m 06.38s , -69d 45m 45.7s) | C | 160 | 17.3 | 13939 | 2024-11-11 07:53:54 | MASTER-OAFA | (14h 10m 34.42s , -69d 14m 48.7s) | C | 60 | 18.0 | 14004 | 2024-11-11 07:54:59 | MASTER-OAFA | (14h 10m 34.00s , -69d 14m 47.3s) | C | 60 | 18.0 | 14070 | 2024-11-11 07:56:05 | MASTER-OAFA | (14h 10m 33.61s , -69d 14m 45.9s) | C | 60 | 18.0 | 14148 | 2024-11-11 07:57:23 | MASTER-OAFA | (13h 28m 02.92s , -69d 12m 43.1s) | C | 60 | 17.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38160. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36130] GRB 241111A: Fermi GBM Final Real-time Localization
by GCN Circulars 11 Nov '24

11 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38159 SUBJECT: GRB 241111A: Fermi GBM Final Real-time Localization DATE: 24/11/11 05:42:32 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 05:31:43 UT on 11 Nov 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241111A (trigger 752995908.077622 / 241111230). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 127.1, Dec = -69.3 (J2000 degrees, equivalent to J2000 08h 28m, -69d 17'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 1.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241111230/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241111230/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241111230/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38159. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36129] GRB 241030B: TESS detection of optical counterpart
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38158 SUBJECT: GRB 241030B: TESS detection of optical counterpart DATE: 24/11/10 22:10:21 GMT FROM: Rahul Jayaraman at MIT <rjayaram(a)mit.edu> R. Jayaraman (MIT), M.M. Fausnaugh (TTU), and G.R. Ricker (MIT) report: The Transiting Exoplanet Survey Satellite (TESS; Ricker et al. JATIS 1 2015) observed GRB 241030B (Klingler et al., GCN 37981; Fermi GBM Team, GCN 37980) during its scheduled sky survey. TESS observed this region continuously from 3.72 days before the trigger to 2.71 days after the trigger, at a cadence of 200 seconds. The GRB occurred during TESS observational Sector 85, and the localization fell within Camera 1, CCD 4. We performed forced difference-imaging photometry at the location of the confirmed X-ray afterglow (Evans et al., GCN 37992) using the full-frame images from the publicly available TICA data archived at MAST (https://archive.stsci.edu/hlsp/tica). Our data reduction routine is described in Fausnaugh et al. 2023 (ApJ 956(2):108). We detect an optical transient at the location of the GRB in the 3 exposures during and after the time of trigger from Klingler et al. The trigger occurred 115 seconds before the end of a concurrent 200-second TESS exposure. The optical transient has a magnitude of 16.40 ± 0.14 in the TESS band in this image. The magnitude falls to 16.50 ± 0.15 in the next exposure, and then 17.08 ± 0.25 mag in the third exposure. These values are in line with the upper limits of 16.2 (r) at T0+1 min, and 17.4 at T0+15 min from Klotz et al., GCN 37989. This circular includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. View this GCN Circular online at https://gcn.nasa.gov/circulars/38158. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36128] LIGO/Virgo/KAGRA S241110br: Updated Sky localization
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38157 SUBJECT: LIGO/Virgo/KAGRA S241110br: Updated Sky localization DATE: 24/11/10 17:46:27 GMT FROM: MUKESH SINGH at Cardiff University <mukesh.singh(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S241110br (GCN Circular 38155). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S241110br For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is well fit by an ellipse with an area of 109 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis): icrs; ellipse(13h24m, -35d57m, 8.22d, 4.20d, 81.40d) Marginalized over the whole sky, the a posteriori luminosity distance estimate is 749 +/- 173 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. PRD 108, 123040 (2023) doi:10.1103/PhysRevD.108.123040 View this GCN Circular online at https://gcn.nasa.gov/circulars/38157. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36127] LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38156 SUBJECT: LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search DATE: 24/11/10 17:08:41 GMT FROM: Erik Blaufuss at University of Maryland, College Park <blaufuss(a)umd.edu> IceCube Collaboration (http://icecube.wisc.edu/) reports: We have performed a search for track-like muon neutrino candidate events detected by IceCube consistent with the sky localization of the low-significance gravitational-wave candidate event S241110bk in a time range of 1000 seconds centered on the alert event time (2024-11-10 11:53:02 UTC to 2024-11-10 12:09:42 UTC) [1,2]. During this time period, IceCube was collecting good quality data. A single hypothesis test was conducted using a Bayesian approach to quantify the joint GW + neutrino event significance, which assumes a binary merger scenario and accounts for known astrophysical priors, such as GW source distance, in the statistical significance estimation [3]. One track-like event was found in spatial and temporal coincidence with the gravitational-wave candidate S241110bk calculated from the map circulated in the S241110bk-2-Preliminary notice. This represents an overall p-value of 0.0089 for the Bayesian search. The p-value measures the consistency of the observed track-like event with the known atmospheric backgrounds for this single map (not accounting for statistical trials from multiple GW events). Further details are available at https://gcn.nasa.gov/missions/icecube and at https://roc.icecube.wisc.edu/public/LvkNuTrackSearch. Properties of the coincident event are shown below: dt(s) RA(deg) Dec(deg) Angular uncertainty(deg) p-value(Bayesian) ------------------------------------------------------------------------------------- 246.18 145.51 20.60 3.18 0.0089 where: dt = Time of track event minus time of GW trigger (sec) Angular uncertainty = Angular uncertainty of track event: the radius of a circle representing 90% CL containment by area. p-value = the p-value for this specific track event from this search. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu [1] M. G. Aartsen et al 2020 ApJL 898 L10 [2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80 [3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017 View this GCN Circular online at https://gcn.nasa.gov/circulars/38156. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36126] LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38156 SUBJECT: LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search DATE: 24/11/10 17:08:41 GMT FROM: Erik Blaufuss at University of Maryland, College Park <blaufuss(a)umd.edu> IceCube Collaboration (http://icecube.wisc.edu/) reports: We have performed a search for track-like muon neutrino candidate events detected by IceCube consistent with the sky localization of the low-significance gravitational-wave candidate event S241110bk in a time range of 1000 seconds centered on the alert event time (2024-11-10 11:53:02 UTC to 2024-11-10 12:09:42 UTC) [1,2]. During this time period, IceCube was collecting good quality data. A single hypothesis test was conducted using a Bayesian approach to quantify the joint GW + neutrino event significance, which assumes a binary merger scenario and accounts for known astrophysical priors, such as GW source distance, in the statistical significance estimation [3]. One track-like event was found in spatial and temporal coincidence with the gravitational-wave candidate S241110bk calculated from the map circulated in the S241110bk-2-Preliminary notice. This represents an overall p-value of 0.0089 for the Bayesian search. The p-value measures the consistency of the observed track-like event with the known atmospheric backgrounds for this single map (not accounting for statistical trials from multiple GW events). Further details are available at https://gcn.nasa.gov/missions/icecube and at https://roc.icecube.wisc.edu/public/LvkNuTrackSearch. Properties of the coincident event are shown below: dt(s) RA(deg) Dec(deg) Angular uncertainty(deg) p-value(Bayesian) ------------------------------------------------------------------------------------- 246.18 145.51 20.60 3.18 0.0089 where: dt = Time of track event minus time of GW trigger (sec) Angular uncertainty = Angular uncertainty of track event: the radius of a circle representing 90% CL containment by area. p-value = the p-value for this specific track event from this search. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu [1] M. G. Aartsen et al 2020 ApJL 898 L10 [2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80 [3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017 View this GCN Circular online at https://gcn.nasa.gov/circulars/38156. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36125] LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38155 SUBJECT: LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate DATE: 24/11/10 13:15:26 GMT FROM: Pawan Tiwari at Gran Sasso Science Institute, Italy <pawan.tiwari(a)gssi.it> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241110br during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-11-10 12:41:23.675 UTC (GPS time: 1415277701.675). The candidate was found by the GstLAL [1], MBTA [2], and PyCBC Live [3] analysis pipelines. S241110br is an event of interest because its false alarm rate, as estimated by the online analysis, is 4.7e-09 Hz, or about one in 6 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241110br After parameter estimation by RapidPE-RIFT [4], the classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), NSBH (<1%), or BNS (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [5] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [5] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is 5%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [6], distributed via GCN notice about 27 seconds after the candidate event time. * bayestar.multiorder.fits,2, an initial localization generated by BAYESTAR [6], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,2. For the bayestar.multiorder.fits,2 sky map, the 90% credible region is 244 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 795 +/- 214 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [2] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 [3] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a [4] Rose et al. (2022) arXiv:2201.05263 and Pankow et al. PRD 92, 023002 (2015) doi:10.1103/PhysRevD.92.023002 [5] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [6] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38155. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36124] LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38154 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations DATE: 24/11/10 08:29:31 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> X. Mao (NAO, CAS), A. Li (BNU), C. Y. Wang (THU), X. L. Chen, Kaushik Chatterjee (YNU), M. H. Zhang, J. W. Hu, M. Zhang and Y. Liu (NAO, CAS) report on behalf of the Einstein Probe team: After the trigger of the gravitational-wave (GW) event S241109bn (LVK Collaboration, GCN 38142), we examined the data of Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP). The 90% credible region of the GW event was occulted by the earth until about 20 minutes after the GW trigger time. The field of view of WXT covered 4.4% of the 90% credible region of the event (598 square degrees) with a duration of about 200 s. The 5-sigma upper limit of the observation in 0.5-4 keV is around 9 x 10^(-11) erg/cm^2/s. Two target-of-opportunity observations by WXT was carried out about 30 minutes and 2 hours after the trigger, beginning at 2024-11-09 12:28:01 (UTC) and 2024-11-09 14:04:15 (UTC) and lasting for around 2800 s and 2400 s, respectively. 59.2% of the 90% credible region of the event was covered by these two observations, with a total area of 5811 square degrees. No new X-ray source is found in these observations. These two observations set 5-sigma upper limits on the 0.5-4 keV flux in the credible region to be approximately 1.3 x 10^(-11) erg/cm^2/s and 1.4 x 10^(-11) erg/cm^2/s, respectively. For queries on more information about these observations and the upper limits, please contact Xuan Mao at the EP science center (ep_ta(a)nao.cas.cn). Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with onboard X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is an international collaborative mission led by the Chinese Academy of Sciences (CAS) and participated by the European Space Agency (ESA), the Max-Planck Institute for Extraterrestrial Physics (MPE) in Germany and the Centre National d’Etudes Spatiales (CNES) in France. View this GCN Circular online at https://gcn.nasa.gov/circulars/38154. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36123] Fermi trigger No 752878030: Global MASTER-Net observations report
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38153 SUBJECT: Fermi trigger No 752878030: Global MASTER-Net observations report DATE: 24/11/10 07:30:32 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB241109.87 (trigger No 752878030,13h 50m 28.08s , -38d 00m 00.0s, R=35.87) errorbox 11218 sec after notice time and 11234 sec after trigger time at 2024-11-09 23:54:19 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenith distance = 62 deg. The sun altitude is -10.4 deg. The galactic latitude b = 23 deg., longitude l = 316 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2663705 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 11255 | 2024-11-09 23:54:19 | MASTER-OAFA | (16h 44m 26.09s , -62d 50m 37.4s) | C | 40 | 15.0 | 11327 | 2024-11-09 23:55:21 | MASTER-OAFA | (16h 24m 27.27s , -63d 08m 12.8s) | C | 60 | 15.5 | Coadd 11355 | 2024-11-09 23:55:59 | MASTER-OAFA | (16h 44m 32.65s , -62d 51m 40.2s) | C | 40 | 15.3 | 11428 | 2024-11-09 23:57:02 | MASTER-OAFA | (16h 24m 33.46s , -63d 09m 14.6s) | C | 60 | 16.3 | Coadd 11447 | 2024-11-09 23:57:32 | MASTER-OAFA | (16h 44m 26.17s , -62d 52m 43.8s) | C | 40 | 15.5 | 11537 | 2024-11-09 23:58:52 | MASTER-OAFA | (16h 24m 26.38s , -63d 10m 16.6s) | C | 60 | 15.9 | Coadd 11543 | 2024-11-09 23:59:08 | MASTER-OAFA | (16h 10m 43.94s , -62d 52m 33.7s) | C | 40 | 15.3 | 11583 | 2024-11-09 23:59:08 | MASTER-OAFA | (16h 10m 43.95s , -62d 52m 33.7s) | C | 120 | 15.9 | Coadd 11672 | 2024-11-10 00:01:06 | MASTER-OAFA | (15h 50m 45.51s , -63d 10m 02.4s) | C | 60 | 16.1 | Coadd 11691 | 2024-11-10 00:01:36 | MASTER-OAFA | (16h 10m 40.03s , -62d 51m 05.4s) | C | 40 | 15.5 | 11821 | 2024-11-10 00:03:46 | MASTER-OAFA | (16h 10m 41.38s , -62d 52m 47.7s) | C | 40 | 15.6 | 11881 | 2024-11-10 00:04:45 | MASTER-OAFA | (14h 26m 50.12s , -68d 37m 06.5s) | C | 40 | 15.6 | 11955 | 2024-11-10 00:06:00 | MASTER-OAFA | (14h 49m 07.71s , -68d 35m 48.7s) | C | 40 | 15.8 | 12118 | 2024-11-10 00:08:42 | MASTER-OAFA | (14h 26m 55.72s , -68d 37m 08.2s) | C | 40 | 15.4 | 12137 | 2024-11-10 00:09:02 | MASTER-OAFA | (14h 26m 56.36s , -68d 38m 01.5s) | C | 40 | 15.9 | 12214 | 2024-11-10 00:10:19 | MASTER-OAFA | (16h 44m 29.48s , -62d 51m 25.4s) | C | 40 | 16.3 | 12344 | 2024-11-10 00:12:28 | MASTER-OAFA | (16h 44m 30.38s , -62d 52m 40.5s) | C | 40 | 16.4 | 12403 | 2024-11-10 00:13:28 | MASTER-OAFA | (16h 44m 32.61s , -62d 51m 18.3s) | C | 40 | 16.5 | 12474 | 2024-11-10 00:14:39 | MASTER-OAFA | (16h 10m 37.73s , -62d 52m 24.1s) | C | 40 | 16.0 | 12615 | 2024-11-10 00:17:00 | MASTER-OAFA | (16h 10m 37.26s , -62d 51m 29.3s) | C | 40 | 16.2 | 12675 | 2024-11-10 00:17:59 | MASTER-OAFA | (16h 10m 44.25s , -62d 52m 31.7s) | C | 40 | 16.2 | 14303 | 2024-11-10 00:45:08 | MASTER-OAFA | (14h 49m 11.92s , -68d 38m 57.6s) | C | 40 | 16.4 | 14293 | 2024-11-10 00:45:08 | MASTER-OAFA | (14h 24m 12.81s , -68d 54m 27.6s) | C | 20 | 17.1 | 14319 | 2024-11-10 00:45:33 | MASTER-OAFA | (14h 24m 12.90s , -68d 54m 28.0s) | C | 20 | 17.1 | 14344 | 2024-11-10 00:45:59 | MASTER-OAFA | (14h 24m 12.93s , -68d 54m 28.6s) | C | 20 | 17.1 | 14392 | 2024-11-10 00:46:36 | MASTER-OAFA | (14h 49m 12.62s , -68d 37m 31.7s) | C | 40 | 16.4 | 14382 | 2024-11-10 00:46:37 | MASTER-OAFA | (14h 24m 15.01s , -68d 53m 03.0s) | C | 20 | 17.1 | 14407 | 2024-11-10 00:47:02 | MASTER-OAFA | (14h 24m 15.06s , -68d 53m 03.8s) | C | 20 | 17.1 | 14433 | 2024-11-10 00:47:27 | MASTER-OAFA | (14h 24m 15.07s , -68d 53m 04.8s) | C | 20 | 17.1 | 14481 | 2024-11-10 00:48:05 | MASTER-OAFA | (14h 49m 07.96s , -68d 38m 08.7s) | C | 40 | 16.5 | 14471 | 2024-11-10 00:48:05 | MASTER-OAFA | (14h 24m 09.46s , -68d 53m 40.6s) | C | 20 | 17.1 | 14496 | 2024-11-10 00:48:31 | MASTER-OAFA | (14h 24m 09.46s , -68d 53m 40.8s) | C | 20 | 17.1 | 14522 | 2024-11-10 00:48:56 | MASTER-OAFA | (14h 24m 09.48s , -68d 53m 41.3s) | C | 20 | 17.1 | 14569 | 2024-11-10 00:49:33 | MASTER-OAFA | (14h 26m 47.74s , -68d 37m 13.1s) | C | 40 | 16.3 | 14559 | 2024-11-10 00:49:33 | MASTER-OAFA | (14h 01m 50.70s , -68d 52m 47.9s) | C | 20 | 16.8 | 14584 | 2024-11-10 00:49:59 | MASTER-OAFA | (14h 01m 50.70s , -68d 52m 48.0s) | C | 20 | 16.8 | 14610 | 2024-11-10 00:50:24 | MASTER-OAFA | (14h 01m 50.79s , -68d 52m 48.2s) | C | 20 | 16.8 | 14657 | 2024-11-10 00:51:02 | MASTER-OAFA | (14h 26m 54.62s , -68d 38m 13.4s) | C | 40 | 16.2 | 14648 | 2024-11-10 00:51:02 | MASTER-OAFA | (14h 01m 56.67s , -68d 53m 48.6s) | C | 20 | 16.7 | 14673 | 2024-11-10 00:51:27 | MASTER-OAFA | (14h 01m 56.62s , -68d 53m 48.9s) | C | 20 | 16.6 | 14698 | 2024-11-10 00:51:53 | MASTER-OAFA | (14h 01m 56.52s , -68d 53m 49.0s) | C | 20 | 16.6 | 14745 | 2024-11-10 00:52:29 | MASTER-OAFA | (14h 26m 50.09s , -68d 39m 14.9s) | C | 40 | 16.3 | 14735 | 2024-11-10 00:52:29 | MASTER-OAFA | (14h 01m 50.85s , -68d 54m 49.6s) | C | 20 | 16.6 | 14760 | 2024-11-10 00:52:55 | MASTER-OAFA | (14h 01m 50.85s , -68d 54m 49.8s) | C | 20 | 16.6 | 14786 | 2024-11-10 00:53:20 | MASTER-OAFA | (14h 01m 50.94s , -68d 54m 50.3s) | C | 20 | 16.6 | 15121 | 2024-11-10 00:58:46 | MASTER-OAFA | (14h 49m 12.13s , -68d 37m 44.6s) | C | 40 | 16.5 | 15111 | 2024-11-10 00:58:46 | MASTER-OAFA | (14h 24m 14.31s , -68d 53m 16.9s) | C | 20 | 17.1 | 15137 | 2024-11-10 00:59:12 | MASTER-OAFA | (14h 24m 14.39s , -68d 53m 17.0s) | C | 20 | 17.1 | 15162 | 2024-11-10 00:59:37 | MASTER-OAFA | (14h 24m 14.42s , -68d 53m 17.5s) | C | 20 | 17.1 | 15207 | 2024-11-10 01:00:12 | MASTER-OAFA | (14h 49m 08.71s , -68d 38m 24.1s) | C | 40 | 16.4 | 15198 | 2024-11-10 01:00:12 | MASTER-OAFA | (14h 24m 10.12s , -68d 53m 56.5s) | C | 20 | 17.1 | 15223 | 2024-11-10 01:00:38 | MASTER-OAFA | (14h 24m 10.08s , -68d 53m 57.3s) | C | 20 | 17.1 | 15248 | 2024-11-10 01:01:03 | MASTER-OAFA | (14h 24m 10.04s , -68d 53m 57.4s) | C | 20 | 17.1 | 15539 | 2024-11-10 01:05:43 | MASTER-OAFA | (14h 49m 14.53s , -68d 38m 31.7s) | C | 40 | 16.5 | 15529 | 2024-11-10 01:05:44 | MASTER-OAFA | (14h 24m 15.73s , -68d 54m 04.9s) | C | 20 | 17.1 | 15554 | 2024-11-10 01:06:09 | MASTER-OAFA | (14h 24m 15.80s , -68d 54m 05.5s) | C | 20 | 17.1 | 15580 | 2024-11-10 01:06:34 | MASTER-OAFA | (14h 24m 15.84s , -68d 54m 05.8s) | C | 20 | 17.1 | 15880 | 2024-11-10 01:11:35 | MASTER-OAFA | (16h 58m 27.66s , -63d 12m 20.0s) | C | 20 | 17.5 | 15906 | 2024-11-10 01:12:00 | MASTER-OAFA | (16h 58m 27.63s , -63d 12m 20.9s) | C | 20 | 17.5 | 15931 | 2024-11-10 01:12:26 | MASTER-OAFA | (16h 58m 27.70s , -63d 12m 22.0s) | C | 20 | 17.6 | 15969 | 2024-11-10 01:13:03 | MASTER-OAFA | (16h 58m 30.58s , -63d 11m 05.4s) | C | 20 | 17.6 | 15994 | 2024-11-10 01:13:29 | MASTER-OAFA | (16h 58m 30.61s , -63d 11m 06.3s) | C | 20 | 17.5 | 16019 | 2024-11-10 01:13:54 | MASTER-OAFA | (16h 58m 30.69s , -63d 11m 07.2s) | C | 20 | 17.5 | 16054 | 2024-11-10 01:14:29 | MASTER-OAFA | (16h 58m 25.36s , -63d 11m 42.2s) | C | 20 | 17.5 | 16079 | 2024-11-10 01:14:54 | MASTER-OAFA | (16h 58m 25.36s , -63d 11m 43.0s) | C | 20 | 17.4 | 16105 | 2024-11-10 01:15:19 | MASTER-OAFA | (16h 58m 25.46s , -63d 11m 44.0s) | C | 20 | 17.5 | 16923 | 2024-11-10 01:28:58 | MASTER-OAFA | (16h 58m 24.84s , -63d 12m 17.1s) | C | 20 | 17.3 | 16949 | 2024-11-10 01:29:23 | MASTER-OAFA | (16h 58m 24.81s , -63d 12m 18.2s) | C | 20 | 17.4 | 16974 | 2024-11-10 01:29:49 | MASTER-OAFA | (16h 58m 24.82s , -63d 12m 19.1s) | C | 20 | 17.3 | 17012 | 2024-11-10 01:30:27 | MASTER-OAFA | (16h 58m 25.35s , -63d 11m 20.0s) | C | 20 | 17.3 | 17038 | 2024-11-10 01:30:52 | MASTER-OAFA | (16h 58m 25.38s , -63d 11m 20.9s) | C | 20 | 17.3 | 17064 | 2024-11-10 01:31:18 | MASTER-OAFA | (16h 58m 25.45s , -63d 11m 21.7s) | C | 20 | 17.3 | 17098 | 2024-11-10 01:31:53 | MASTER-OAFA | (16h 58m 32.23s , -63d 12m 23.1s) | C | 20 | 17.3 | 17124 | 2024-11-10 01:32:18 | MASTER-OAFA | (16h 58m 32.25s , -63d 12m 23.7s) | C | 20 | 17.2 | 17149 | 2024-11-10 01:32:44 | MASTER-OAFA | (16h 58m 32.27s , -63d 12m 24.5s) | C | 20 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38153. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36122] Integral GRB241109.89: Global MASTER-Net observations report
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38152 SUBJECT: Integral GRB241109.89: Global MASTER-Net observations report DATE: 24/11/10 06:57:41 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Integral GRB241109.89 (trigger No 10977,18h 41m 18.94s , -04d 57m 00.0s, R=0.0492) errorbox 10450 sec after notice time and 10459 sec after trigger time at 2024-11-10 00:19:23 UT, with upper limit up to 17.2 mag. Observations started at twilight. The observations began at zenith distance = 67 deg. The sun altitude is -15.1 deg. The galactic latitude b = -1 deg., longitude l = 28 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2663731 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 10464 | MASTER-OAFA | C | 10 | 16.8 | 10508 | MASTER-OAFA | C | 15 | 16.9 | 10558 | MASTER-OAFA | C | 30 | 17.0 | 10603 | MASTER-OAFA | C | 30 | 17.0 | 10650 | MASTER-OAFA | C | 30 | 17.0 | 10685 | MASTER-OAFA | C | 30 | 17.0 | 10721 | MASTER-OAFA | C | 30 | 17.0 | 10780 | MASTER-OAFA | C | 60 | 17.2 | 10846 | MASTER-OAFA | C | 60 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38152. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36121] LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38151 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations DATE: 24/11/10 03:10:03 GMT FROM: Motoko Serino at Aoyama Gakuin U. <serino(a)phys.aoyama.ac.jp> Y. Kondo, S. Sugita, M. Serino, Y. Kawakubo, H. Hiramatsu, H. Nishikawa (AGU) H. Negoro, M. Nakajima, K. Takagi (Nihon U.), N. Kawai, T. Mihara, (RIKEN), report on behalf of the MAXI team: We examined MAXI/GSC all-sky X-ray images (2-20 keV) after compact binary merger candidate S241109bn at 2024-11-09 11:59:24.899 UTC (GCN 38142, 38149). At the trigger time of S241109bn, the high-voltage of MAXI/GSC was on. The instantaneous field of view of GSC at the GW trigger time covered 1% of the 90% credible region of the Bilby sky map, in which we found no significant new X-ray source. The first one-orbit (92 min) scan observation with GSC after the event covered 68% of the 90% credible region of the Bilby skymap from 11:59:24 to 13:31:23 UTC (T0+0 to T0+5519 sec). No significant new source was found in the region in the one-orbit scan observation. A typical 1-sigma averaged upper limit obtained in one scan observation is 20 mCrab at 2-20 keV. If you require information about X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email. View this GCN Circular online at https://gcn.nasa.gov/circulars/38151. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36120] EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
by GCN Circulars 10 Nov '24

10 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38150 SUBJECT: EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory DATE: 24/11/10 00:34:38 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> WeiKang Zheng, Ryan Chornock, Natalie LeBaron, Xinze Guo, William Wu Alexei V. Filippenko (UCB), and Xuhui Han, Pinpin Zhang (NAOC) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, automatically responded to EP241109a (Li et al., GCN 38140) starting at 06:09 UT, 7 minutes after the trigger. A set of images with 20s exposure time were obtained in B, V, R I and clear (roughly R) filters. Observations lasted for about 3.5 hours. We detected the flare star reported by Perez-Garcia et al. (GCN 38141) in all our images. Photometry of the star show that its brightness decreased from the start of our observation in all filters, especially in B band which decreased by nearly 3 mag. The light curves became flat after about 2.5 hours after trigger in all bands. A spectrum was also taken with the Kast spectrograph on the 3 m Shane telescope at Lick Observatory. Observations was performed at about 2.3 hours after the trigger, covering the 3500-10,000 A wavelength range, with an exposure time of 300s. The spectrum shows a red continuum flux overlapped with strong Balmer emission lines as well as Ca II H&K and TiO emission lines, consistent with a typical dMe star spectrum. The flux below ~4000A show a bit excess, which might be caused by the flare, compared with the typical dMe star spectrum at quiescent time. Based on the above photometry and spectroscopy results, we therefore confirm that this EP241109a event is truly associated with this stellar flare. View this GCN Circular online at https://gcn.nasa.gov/circulars/38150. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36119] LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38149 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification DATE: 24/11/09 23:38:36 GMT FROM: Aditya Vijaykumar <aditya.vijaykumar(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Hanford Observatory (H1) and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S241109bn (GCN Circular 38142). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S241109bn Based on posterior support from parameter estimation [1], under the assumption that the candidate S241109bn is astrophysical in origin, the probability that at least one of the compact objects is consistent with a neutron star (HasNS) is <1%. [2] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [2] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is 43%. Preliminary information from parameter estimation seems to indicate a much smaller NSBH probability than initially reported (GCN Circular 38142), and almost certainly a BBH origin. For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 10138 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 603 +/- 159 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. PRD 108, 123040 (2023) doi:10.1103/PhysRevD.108.123040 [2] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbez View this GCN Circular online at https://gcn.nasa.gov/circulars/38149. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36118] INTEGRAL detection of a burst from 1E 1841-045
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38148 SUBJECT: INTEGRAL detection of a burst from 1E 1841-045 DATE: 24/11/09 22:39:35 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti(a)inaf.it> S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: a burst from the magnetar 1E1841-045 has been detected by IBAS in the IBIS/ISGRI data at 21:25:02 of 2024 November 9 (IBAS Alert n. 10977) The burst had a duration of about 0.15 s and a fluence of 2x10e-8 erg/cm2 in the 20-200 keV energy range. View this GCN Circular online at https://gcn.nasa.gov/circulars/38148. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36117] EP241107a: AbAO optical upper limit
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38147 SUBJECT: EP241107a: AbAO optical upper limit DATE: 24/11/09 22:30:15 GMT FROM: Alexei Pozanenko at IKI, Moscow <grb.alex(a)gmail.com> N. Pankov (HSE, IKI), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI) report on behalf of GRB IKI FuN: We observed the field of EP241107a (Zhou et al., GCN 38112) with the AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on 2024-11-08 (UT) 16:34:02. We do not detect the optical afterglow (Odeh et al., GCN 38115; SVOM/C-GFT team, GCN 38116; Lipunov et al., GCN 38117; Mohan et al., GCN 38118; Busmann et al., GCN 38120; Adami et al., GCN 38122; Quirola-Vasquez et al., GCN 38126; Li et al., 38127; Odeh et al., GCN 38128; Kong et al., GCN 38131; Zheng et al., GCN 38136). Preliminary photometry of the field is following Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2024-11-08 16:34:02 1.12545 R 74*60 n/d n/d 21.6 The photometry is based on nearby USNO-B1.0 stars. View this GCN Circular online at https://gcn.nasa.gov/circulars/38147. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36116] LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38146 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations DATE: 24/11/09 20:18:17 GMT FROM: Utkarsh Pathak at IIT Bombay <utkarshpathak.07(a)gmail.com> U. Pathak (IITB) reports on behalf of the Fermi-GBM Team: For S241109bn (GCN 38142) and using the update bayestar skymap, Fermi-GBM was observing 71.8% of the localization probability at event time. There was no Fermi-GBM onboard trigger around the event time of the LIGO/Virgo/KAGRA (LVK) detection of GW trigger S241109bn. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around merger time, and also identified no counterpart candidates. Part of the LVK localization region is behind the Earth for Fermi, located at an RA=229.0, Dec=-22.5 with a radius of 67.7 degrees. We therefore set upper limits on impulsive gamma-ray emission for the GW localization region visible to Fermi at merger time. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV, weighted by GW localization probability (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------ 0.128 s: 1.2 2.0 4.6 1.024 s: 0.34 0.59 1.2 8.192 s: 0.13 0.24 0.53 Assuming the median luminosity distance of 602.6 Mpc from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^50 erg/s): Timescale Soft Normal Hard ------------------------------------ 0.128s: 0.080 0.122 0.466 1.024s: 0.023 0.036 0.122 8.192s: 0.009 0.015 0.054 View this GCN Circular online at https://gcn.nasa.gov/circulars/38146. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36115] GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38145 SUBJECT: GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart DATE: 24/11/09 19:27:40 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), D. Akl (AUS), S. Antier (OCA), Jean-Luc Atteia (IRAP), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Francis Fortin (IRAP), J.-G. Ducoin (CPPM), Simona Lombardo (LAM), Francesco Magnani (CPPM), and Margarita Pereyra (UNAM) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Jean-Luc Atteia (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV) report: We again imaged the field of GRB 241108A detected by SVOM/ECLAIRs (Sadibekova et al., GCN Circ. 38132) during the commissioning of the COLIBRÍ (SVOM/F-GFT) telescope at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico. We observed with the engineering test camera in a red filter that approximates SDSS r. The data were reduced using custom software and then analysed and calibrated against the PS1 catalog using the STDWeb service. Our field is centered on the XRT source detected at 08:14:33.07 -07:05:09.9 J2000 (Burrows et al., GCN Circ. 38139). In 7080 seconds of exposure from 2024-11-09 09:01 to 12:52 UTC (1.08 to 1.24 days after the trigger), we detect no new sources within the XRT uncertainty region to a 3-sigma limiting AB magnitude of: r > 23.6 We do detect a two point source within the uncertainty region and one just outside it, but these are also present in the earlier PS1 image at a similar magnitude and therefore are unlikely to be the optical counterpart of the GRB. We warmly thank the COLIBRÍ engineering team and the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir. We warmly thank the GRANDMA IJCLAB team and S. Karpov for the access of the STDWeb service for STDPipe. View this GCN Circular online at https://gcn.nasa.gov/circulars/38145. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36114] LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38144 SUBJECT: LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification DATE: 24/11/09 19:15:51 GMT FROM: MUKESH SINGH at Cardiff University <mukesh.singh(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Livingston Observatory (L1) and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S241109p (GCN Circular 38138). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S241109p After parameter estimation by RapidPE-RIFT [2], the updated classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), NSBH (<1%), or BNS (<1%). For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 1761 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2282 +/- 1082 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. PRD 108, 123040 (2023) doi:10.1103/PhysRevD.108.123040 [2] Rose et al. (2022) arXiv:2201.05263 and Pankow et al. PRD 92, 023002 (2015) doi:10.1103/PhysRevD.92.023002 View this GCN Circular online at https://gcn.nasa.gov/circulars/38144. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36113] LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38143 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report DATE: 24/11/09 13:10:58 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the LIGO/Virgo/KAGRA S241109bn errorbox 16 sec after trigger time at 2024-11-09 11:59:40 UT, with upper limit up to 19.9 mag. The observations began at zenith distance = 60 deg. The sun altitude is -24.0 deg. The galactic latitude b = -22 deg., longitude l = 314 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=23757 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 46 | 2024-11-09 11:59:40 | MASTER-Tunka | (03h 17m 17.41s , +29d 28m 17.8s) | C | 60 | 18.7 | 119 | 2024-11-09 12:00:52 | MASTER-Tunka | (03h 08m 12.16s , +29d 28m 34.7s) | C | 60 | 19.3 | 197 | 2024-11-09 12:02:11 | MASTER-Tunka | (03h 17m 20.04s , +29d 30m 10.6s) | C | 60 | 19.6 | 270 | 2024-11-09 12:03:24 | MASTER-Tunka | (03h 08m 08.76s , +29d 28m 31.1s) | C | 60 | 19.6 | 358 | 2024-11-09 12:04:52 | MASTER-Tunka | (06h 50m 17.97s , +54d 17m 35.7s) | C | 60 | 19.3 | 418 | 2024-11-09 12:04:52 | MASTER-Tunka | (06h 50m 17.97s , +54d 17m 35.7s) | C | 180 | 19.9 | Coadd 441 | 2024-11-09 12:06:14 | MASTER-Tunka | (07h 04m 01.27s , +54d 19m 14.3s) | C | 60 | 19.4 | 501 | 2024-11-09 12:06:14 | MASTER-Tunka | (07h 04m 01.27s , +54d 19m 14.3s) | C | 180 | 19.8 | Coadd 525 | 2024-11-09 12:07:39 | MASTER-Tunka | (03h 17m 24.44s , +29d 29m 23.9s) | C | 60 | 19.7 | 585 | 2024-11-09 12:07:39 | MASTER-Tunka | (03h 17m 24.43s , +29d 29m 23.9s) | C | 180 | 19.9 | Coadd 599 | 2024-11-09 12:08:52 | MASTER-Tunka | (03h 08m 06.68s , +29d 28m 20.6s) | C | 60 | 19.7 | 659 | 2024-11-09 12:08:52 | MASTER-Tunka | (03h 08m 06.68s , +29d 28m 20.5s) | C | 180 | 19.7 | Coadd 685 | 2024-11-09 12:10:18 | MASTER-Tunka | (06h 50m 24.29s , +54d 16m 39.7s) | C | 60 | 19.3 | 758 | 2024-11-09 12:11:31 | MASTER-Tunka | (07h 04m 05.00s , +54d 18m 57.3s) | C | 60 | 19.5 | 844 | 2024-11-09 12:12:58 | MASTER-Tunka | (03h 17m 20.88s , +29d 28m 58.5s) | C | 60 | 18.8 | 917 | 2024-11-09 12:14:11 | MASTER-Tunka | (03h 08m 12.30s , +29d 30m 19.5s) | C | 60 | 16.9 | 1002 | 2024-11-09 12:15:35 | MASTER-Tunka | (06h 50m 19.98s , +54d 17m 28.4s) | C | 60 | 19.4 | 1085 | 2024-11-09 12:16:58 | MASTER-Tunka | (04h 03m 15.82s , +52d 17m 44.6s) | C | 60 | 18.7 | 1145 | 2024-11-09 12:16:58 | MASTER-Tunka | (04h 03m 15.82s , +52d 17m 44.6s) | C | 180 | 19.0 | Coadd 1158 | 2024-11-09 12:18:12 | MASTER-Tunka | (04h 16m 14.49s , +52d 17m 01.7s) | C | 60 | 18.6 | 1238 | 2024-11-09 12:19:32 | MASTER-Tunka | (03h 17m 23.75s , +29d 28m 36.6s) | C | 60 | 19.0 | 1311 | 2024-11-09 12:20:45 | MASTER-Tunka | (03h 08m 09.79s , +29d 30m 04.7s) | C | 60 | 19.4 | 1389 | 2024-11-09 12:22:02 | MASTER-Tunka | (04h 03m 13.82s , +52d 17m 17.8s) | C | 60 | 17.6 | 1463 | 2024-11-09 12:23:16 | MASTER-Tunka | (04h 16m 22.30s , +52d 18m 59.7s) | C | 60 | 16.6 | 1526 | 2024-11-09 12:24:20 | MASTER-Tunka | (03h 17m 18.98s , +29d 29m 37.5s) | C | 60 | 19.3 | 1599 | 2024-11-09 12:25:33 | MASTER-Tunka | (03h 08m 08.00s , +29d 30m 36.0s) | C | 60 | 19.7 | 1676 | 2024-11-09 12:26:50 | MASTER-Tunka | (04h 03m 17.81s , +52d 17m 54.6s) | C | 60 | 18.5 | 1933 | 2024-11-09 12:31:06 | MASTER-Tunka | (07h 04m 09.13s , +54d 18m 36.6s) | C | 60 | 18.4 | 2018 | 2024-11-09 12:32:32 | MASTER-Tunka | (03h 17m 22.12s , +29d 29m 05.6s) | C | 60 | 19.8 | 2093 | 2024-11-09 12:33:46 | MASTER-Tunka | (03h 08m 12.87s , +29d 30m 26.8s) | C | 60 | 19.8 | 2177 | 2024-11-09 12:35:11 | MASTER-Tunka | (07h 04m 07.96s , +54d 17m 51.9s) | C | 60 | 17.4 | 2237 | 2024-11-09 12:35:11 | MASTER-Tunka | (07h 04m 07.97s , +54d 17m 51.9s) | C | 180 | 17.6 | Coadd 2249 | 2024-11-09 12:36:22 | MASTER-Tunka | (07h 04m 08.18s , +54d 18m 51.8s) | C | 60 | 16.7 | 2322 | 2024-11-09 12:37:35 | MASTER-Tunka | (06h 50m 31.54s , +54d 17m 14.9s) | C | 60 | 17.6 | 2382 | 2024-11-09 12:37:35 | MASTER-Tunka | (06h 50m 31.54s , +54d 17m 14.9s) | C | 180 | 17.7 | Coadd 2395 | 2024-11-09 12:38:49 | MASTER-Tunka | (06h 50m 25.08s , +54d 16m 13.8s) | C | 60 | 16.8 | 2467 | 2024-11-09 12:40:00 | MASTER-Tunka | (06h 50m 32.11s , +54d 16m 31.8s) | C | 60 | 16.5 | 2547 | 2024-11-09 12:41:21 | MASTER-Tunka | (04h 16m 22.23s , +52d 18m 52.2s) | C | 60 | 19.0 | 2621 | 2024-11-09 12:42:35 | MASTER-Tunka | (04h 16m 22.42s , +52d 17m 22.2s) | C | 60 | 18.9 | 2681 | 2024-11-09 12:42:35 | MASTER-Tunka | (04h 16m 22.42s , +52d 17m 22.1s) | C | 180 | 19.6 | Coadd 2693 | 2024-11-09 12:43:46 | MASTER-Tunka | (04h 16m 26.54s , +52d 19m 08.7s) | C | 60 | 18.5 | 2767 | 2024-11-09 12:45:01 | MASTER-Tunka | (04h 03m 14.18s , +52d 18m 07.5s) | C | 60 | 18.5 | 2827 | 2024-11-09 12:45:01 | MASTER-Tunka | (04h 03m 14.18s , +52d 18m 07.5s) | C | 180 | 19.0 | Coadd 2838 | 2024-11-09 12:46:12 | MASTER-Tunka | (04h 03m 13.71s , +52d 19m 08.9s) | C | 60 | 17.5 | 2911 | 2024-11-09 12:47:25 | MASTER-Tunka | (04h 03m 20.25s , +52d 18m 10.4s) | C | 60 | 18.8 | 3096 | 2024-11-09 12:50:29 | MASTER-Tunka | (07h 04m 15.57s , +54d 17m 17.7s) | C | 60 | 16.8 | 3169 | 2024-11-09 12:51:42 | MASTER-Tunka | (07h 04m 13.39s , +54d 18m 36.3s) | C | 60 | 18.0 | 3244 | 2024-11-09 12:52:58 | MASTER-Tunka | (07h 04m 13.65s , +54d 16m 54.5s) | C | 60 | 19.1 | 3325 | 2024-11-09 12:54:19 | MASTER-Tunka | (04h 16m 27.69s , +52d 19m 18.9s) | C | 60 | 19.4 | 3400 | 2024-11-09 12:55:34 | MASTER-Tunka | (04h 16m 21.11s , +52d 18m 32.8s) | C | 60 | 19.5 | 3474 | 2024-11-09 12:56:48 | MASTER-Tunka | (04h 16m 20.44s , +52d 19m 34.4s) | C | 60 | 19.5 | 3554 | 2024-11-09 12:58:07 | MASTER-Tunka | (06h 07m 40.88s , +52d 20m 32.2s) | C | 60 | 19.3 | 3626 | 2024-11-09 12:59:20 | MASTER-Tunka | (06h 20m 54.32s , +52d 21m 03.6s) | C | 60 | 19.4 | 3700 | 2024-11-09 13:00:33 | MASTER-Tunka | (06h 07m 44.43s , +52d 22m 11.8s) | C | 60 | 19.3 | 3779 | 2024-11-09 13:01:53 | MASTER-Tunka | (06h 20m 51.01s , +52d 21m 03.6s) | C | 60 | 19.3 | 3853 | 2024-11-09 13:03:06 | MASTER-Tunka | (06h 07m 48.85s , +52d 22m 12.7s) | C | 60 | 19.3 | 3958 | 2024-11-09 13:04:51 | MASTER-Tunka | (06h 24m 27.80s , +54d 17m 07.5s) | C | 60 | 19.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38143. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36112] LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38142 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate DATE: 24/11/09 12:36:57 GMT FROM: Biswajit Banerjee at Gran Sasso Science Institute (GSSI) <biswajit.banerjee(a)gssi.it> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241109bn during real-time processing of data from LIGO Hanford Observatory (H1) and Virgo Observatory (V1) at 2024-11-09 11:59:24.899 UTC (GPS time: 1415188782.899). The candidate was found by the GstLAL [1], MBTA [2], and PyCBC Live [3] analysis pipelines. S241109bn is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.4e-11 Hz, or about one in 1e3 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241109bn The initial classification of the GW signal, based on chirp-mass information only [3], in order of descending probability, is NSBH (62%), BBH (38%), Terrestrial (<1%), or BNS (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is 21%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [4] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is 83%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 24 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 10353 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 583 +/- 171 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [2] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 [3] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a [4] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [5] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38142. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36111] EP241109a: confirmation of a stellar flare by BOOTES-7
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38141 SUBJECT: EP241109a: confirmation of a stellar flare by BOOTES-7 DATE: 24/11/09 09:32:04 GMT FROM: ipg(a)iaa.es I. Perez-Garcia, S.-Y. Wu, A. J. Castro-Tirado, E. J. Fernandez-Garcia, M.D. Caballero-Garcia, S. Guziy, G. Garcia-Segura, R. Sanchez-Ramirez (IAA-CSIC), Y.-D. Hu (INAF-OAB), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), L. Hernandez-Garcia (Univ. de Valparaiso), M. Gritsevich (Univ. of Helsinki), D.-R. Xiong (Yunnan Observatories of CAS), B.-B. Zhang (Nanjing Univ.) and A. Maury (Space, San Pedro de Atacama), on behalf of a larger collaboration, report: Following the detection of EP241109a by EP-WXT (Li et al. [GCNC 38140](https://gcn.nasa.gov/circulars/38140)), the 0.6m BOOTES-7 robotic telescope at San Pedro de Atacama (Chile) responded to the alert on Nov. 9, 06:10 UT (i.e. 2-min after trigger, and 1-h after the event). Within the reported EP-FXT error circle we find that the star [Gaia DR3 2534635509050352256](https://vizier.cds.unistra.fr/viz-bin/VizieR-5?-ref=VIZ672f2a07ac09c&-out.add=.&-source=I/355/gaiadr3&-c=018.36205003099%20%2b00.01880744277,eq=ICRS,rs=2&-out.orig=o) decreasing 0.8 mag in brightness (clear filter) during a 40 min time interval, confirming EP241109a as due to a stellar flare. Multiband observations are ongoing. We thank the staff at San Pedro de Atacama Celestial Observations for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38141. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36110] EP241109a: EP on-board trigger and autonomous follow-up observation
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38140 SUBJECT: EP241109a: EP on-board trigger and autonomous follow-up observation DATE: 24/11/09 08:26:08 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> A.Li (BNU), C.-Y. Wang (THU), H.-Y. Liu (NAO, CAS), Y.-C. Fu (BNU), X.-L. Chen, Kaushik Chatterjee (YNU), and H. W. Pan (NAO,CAS) report on behalf of the Einstein Probe team: We report on the detection of an X-ray transient detected by EP-WXT, EP241109a, which triggered the on-board processing unit at 2024-11-09T06:01:55Z (UTC) (trigger ID: 01709118383). An autonomous observation on the X-ray transient was performed by the EP-FXT, which detected an X-ray source at R.A. = 18.3599 deg, DEC = 0.0184 deg (J2000) with an uncertainty of about 15 arcsecs (radius, 90% C.L. statistical and systematic), consistent with the position of the WXT transient within the uncertainties. In the GAIA DR3 database, there is a close star (effective temperature is about 3200 K, distance is about 71.83 pc) within the EP-FXT error circle of EP241109a. Hence, the possibility that EP241109a is a stellar flare event cannot be ruled out. Further follow-up observations are encouraged to explore the orgin of EP241109a. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/38140. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36109] GRB 241108A: Swift-XRT observations
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38139 SUBJECT: GRB 241108A: Swift-XRT observations DATE: 24/11/09 07:43:33 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), M. A. Williams (PSU), S. Dichiara (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected burst GRB 241108A, collecting 2.9 ks of Photon Counting (PC) mode data between T0+43.8 ks and T0+50.6 ks. One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 1: RA (J2000.0): 123.6378 = 08:14:33.07 Dec (J2000.0): -7.0861 = -07:05:09.9 Error: 4.7 arcsec (radius, 90% conf.) Count-rate: (5.0 [+2.0, -1.6])e-3 ct s^-1 Distance: 494 arcsec from SVOM/ECLAIRs position. Flux: (2.99 [+1.17, -0.93])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021729. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38139. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36108] LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
by GCN Circulars 09 Nov '24

09 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38138 SUBJECT: LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate DATE: 24/11/09 04:22:00 GMT FROM: Pan Guo at KAGRA <panguocas(a)gmail.com> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241109p during real-time processing of data from LIGO Livingston Observatory (L1) and Virgo Observatory (V1) at 2024-11-09 03:33:17.997 UTC (GPS time: 1415158415.997). The candidate was found by the GstLAL [1] analysis pipeline. S241109p is an event of interest because its false alarm rate, as estimated by the online analysis, is 6e-11 Hz, or about one in 1e3 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241109p The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), NSBH (<1%), or BNS (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [2] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [2] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is <1%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [3], distributed via GCN notice about 26 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [3], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 6741 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2807 +/- 1011 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [2] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [3] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38138. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36107] EP241107A: MASTER optical observations of xray transient
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38137 SUBJECT: EP241107A: MASTER optical observations of xray transient DATE: 24/11/08 21:06:14 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> M.Gulyaev, V.Lipunov, E.Gorbovskoy, D.Vlasenko, I.Panchenko, A.Kuznetsov, P.Balanutsa, G.Antipov, A.Yudin, K.Zhirkov, N.Tiurina, A.Sankovich, Ya.Kechin, V.Senik, A.Chasovnikov, V.Topolev, K.Vetrov (Lomonosov MSU), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO RAS), O.Gress, N.Budnev(ISU), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A.Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), MASTER Global robotic net (http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L) started observation of EP241107A (EP-WXT Zhou et al., GCN 38112, Ttrigger=14:10:23 UT) at MASTER-Kislovodsk (covermap at https://master.sai.msu.ru/site/master2/event.php?id=2661310 , Lipunov et al. GCN 38117 ) at 15:23:24UT (See table with unfiltered mlim ) There is optical source (afterglow) MASTER OT J022002.50+032001.8 with unfiltered mOT=~19.0 at 540s summary image (9*60s) in interval 15:23:24-16:07:41UT and mOT=19.2 at interval 2024-11-07 17:50:16+2340s (mlim=20.5) at position of optical source, discovered by AKO (Odeh et al. GCN 38115, T=15:53:50 Ic=17.85) and observed by SVOM Kang et al, GCN 38116; GIT Mohan et al. GCN 38118; NAOC Li et al. GCN 39127, FTW, Busman et al. GCN 38120, OHP, Adami et al. GCN 38122, GEMINI, Quirola-Vasquez et al. GCN 38126, LOT/Kinder, Kong et al. GCN 38131, KAIT Zheng et al. GCN 38136) This OT is the most probably GRB afterglow by light curve features and by energy release. Reduction will be continued. View this GCN Circular online at https://gcn.nasa.gov/circulars/38137. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36106] EP241107a: KAIT optical observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38136 SUBJECT: EP241107a: KAIT optical observations DATE: 24/11/08 19:28:59 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> WeiKang Zheng (UCB), Xuhui Han (NAOC), Pinpin Zhang (NAOC) and Alexei V. Filippenko (UCB) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, observed the field of EP241107a (Zhou et al., GCN 38112) on Nov 08 UT starting at ~0.67d after the trigger. A set of 60x60s images were obtained in the clear (roughly R) filters. We detect the optical afterglow (Odeh et al., GCN 38115; SVOM/C-GFT team, GCN 38116; Lipunov et al., GCN 38117; Mohan et al., GCN 38118; Busmann et al., GCN 38120; Adami et al., GCN 38122; Quirola-Vasquez et al., GCN 38126; Li et al., GCN 38127; Odeh et al., GCN 38128; Kong et al., GCN 38131) in the coadd image and measure its brightness to be 20.5 +/- 0.1 at a mid time of ~0.71d after trigger. View this GCN Circular online at https://gcn.nasa.gov/circulars/38136. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36105] GRB 241108A: Swift ToO observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38135 SUBJECT: GRB 241108A: Swift ToO observations DATE: 24/11/08 19:21:11 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the SVOM/ECLAIRs GRB 241108A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021729 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the SVOM/ECLAIRs event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38135. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36104] GRB 241030A: TESS observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38134 SUBJECT: GRB 241030A: TESS observations DATE: 24/11/08 19:09:39 GMT FROM: Rahul Jayaraman at MIT <rjayaram(a)mit.edu> R. Jayaraman (MIT), M.M. Fausnaugh (TTU), R. Vanderspek (MIT), G.R. Ricker (MIT) report: The Transiting Exoplanet Survey Satellite (TESS; Ricker et al. JATIS 1 2015) observed GRB 241030A (Klingler et al., GCN 37956; Fermi GBM Team, GCN 37955) during its scheduled sky survey. Further information on the TESS observation times and public data postings were given in Petitpas et al., GCN 38050. We performed forced difference-imaging photometry at the location of the confirmed X-ray afterglow (Beardmore et al., GCN 37962) using the full-frame images from the publicly available TICA data archived at MAST (https://archive.stsci.edu/hlsp/tica). Our analysis routine is described in Fausnaugh et al. 2023 (ApJ 956(2):108). The trigger occurred 90 seconds before the end of a concurrent TESS 200-second exposure. The light curve shows a rapid rise that peaks ~600 seconds after the burst, reaching an apparent magnitude of ~12 in the TESS band (600 nm–1000 nm). The light curve has an initial decay slope of -2.07 ± 0.04, with a subsequent shallower slope. It decays to the detection limit of 17.5 (3-sigma, 200s exposure) 0.6 d after the trigger time. These results are consistent with measurements of the afterglow rise and peak from Swift-UVOT (Breeveld et al., GCN 37974). The light curve fades at a rate consistent with other optical observations in red bands (Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; An et al., GCN 37960; Higuchi et al, GCN 37963; and Qiu et al., GCN 37965). This circular includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. View this GCN Circular online at https://gcn.nasa.gov/circulars/38134. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36103] GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38133 SUBJECT: GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart DATE: 24/11/08 18:54:20 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> J.-G. Ducoin (CPPM), Francesco Magnani (CPPM), Alan M. Watson (UNAM), S. Antier (OCA), Damien Dornic (CPPM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), D. Akl (AUS), Jean-Luc Atteia (IRAP), Nathaniel R. Butler (ASU), Francis Fortin (IRAP), Simona Lombardo (LAM), and Margarita Pereyra (UNAM) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Jean-Luc Atteia (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV) report: We imaged the field of GRB 241108A detected by SVOM/ECLAIRs (Sadibekova et al., GCN Circ. 38132) during the commissioning of the COLIBRÍ (SVOM/F-GFT) telescope at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico. We observed with the engineering test camera in a red filter that approximates SDSS r. The data were reduced using custom software and then analysed and calibrated against the PS1 catalog using the STDWeb service. Our field covers a 13 arcmin square region centered on the ECLAIRS position and does not cover the whole uncertainty region. In 9840 seconds of exposure from 2024-11-08 08:47 to 12:34 (1.63 to 5.41 hours after the trigger, we detect no sources other than those previously identified in the PS1 or GAIA DR3 catalogs to a 5-sigma limiting AB magnitude of: r > 22.3 We warmly thank the COLIBRÍ engineering team and the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir. We warmly thank the GRANDMA IJCLAB team and S. Karpov for the access of the STDWeb service for STDPipe. View this GCN Circular online at https://gcn.nasa.gov/circulars/38133. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36102] GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38132 SUBJECT: GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs DATE: 24/11/08 17:37:15 GMT FROM: Stéphane Schanne at CEA Paris-Saclay/IRFU <s.schanne(a)cea.fr> SVOM/ECLAIRs Commissioning Team: Tatyana Sadibekova, Stéphane Schanne, Nicolas Dagoneau, Hervé Le Provost, Frédéric Chateau (CEA), Jean-Luc Atteia, Laurent Bouchet, Sebastien Guillot, Juliette Alaux, Hui Yang (IRAP), Tais Maiolino (LUPM), Wenjin Xie, Donghua Zhao (NAOC), Floriane Cangemi (APC), Karine Mercier, Marie-Claire Charmeau, Stefano Crepaldi (CNES) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Olivier Godet (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV) Report on behalf of the SVOM team: During the commissioning phase, the SVOM/ECLAIRs telescope detected and localized the likely weak long duration GRB 241108A (SVOM trigger reference: sb24110802) at 2024-11-08T07:09:55 UTC (Tb). The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by the Image Trigger (IMT) which sent a single Alert message, with a signal-to-noise ratio of 7.1 in the 20-120 keV energy band over a time window of 20.48 s starting at Tb. The Alert was produced 75 s before the entry to SAA, such that the Alert sequence was interrupted. The on-ground data analysis confirms a weak point-like source in the reconstructed sky image. The burst localization is RA, Dec = 123.72, -7.19 (J2000). The statistical uncertainty on this position is 11.9 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature. SVOM did not slew to the burst since the detection significance was below slew threshold. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES, and IRAP. The SVOM point of contact for 2024-11-08T07:09:55this burst is: s.schanne AT cea.fr. View this GCN Circular online at https://gcn.nasa.gov/circulars/38132. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36101] EP241107a: Kinder optical follow-up observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38131 SUBJECT: EP241107a: Kinder optical follow-up observations DATE: 24/11/08 16:55:04 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> A. K. H. Kong (NTHU), A. Aryan, T.-W. Chen, C.-S. Lin (all NCU), Z. N. Wang (HNAS), J. Gillanders (Oxford), S. J. Smartt (Oxford/QUB), Y. J. Yang, A. Sankar. K, Y.-C. Pan, C.-C. Ngeow, M.-H. Lee, C.-H. Lai, H.-Y. Hsiao, W.-J. Hou, H.-C. Lin, J.-K. Guo (all NCU), S. Yang, L. L. Fan, G. H. Sun (all HNAS), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report: We observed the field of the fast X-ray transient EP241107a (Zhou et al., GCN 38112; Odeh et al., GCN 38115; SVOM/C-GFT team, GCN 38116; Lipunov et al., GCN 38117; Mohan et al., GCN 38118; Busmann et al., GCN 38120; Adami et al., GCN 38122; Quirola-Vasquez et al., GCN 38126; Li et al., 38127; Odeh et al., GCN 38128) using the 1m LOT at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2024arXiv240609270C). The first LOT epoch of observations started at 14:38 UTC on the 8th of November 2024 (MJD = 60622.610), 1.02d after the EP WXT trigger. We utilized the astroalign (Beroiz et al. 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al. 2022, ApJ, 935, 167) packages to align and stack the individual frames. We detect the optical counterpart reported by Odeh et al. (GCN 38115) in the stacked image. Further, we utilized the Python-based package AutoPhOT (Brennan & Fraser, 2022, A&A, 667, A62) to perform the PSF photometry on our stacked frame. The details of the observations and measured PSF photometry (in the AB system) are as follows: Telescope | Filter | MJD (start) | t-t0 (d) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass LOT | r | 60622.610 | 1.02 | 300 * 6 | 21.53 +/- 0.32 | 1".34 | 1.06 The presented magnitudes are calibrated using the field stars from the PanSTARRS-1 catalog and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E(B-V) = 0.04 AB mag in the direction of the transient (Schlafly & Finkbeiner 2011). The potential host galaxy has an r-band magnitude of 22.69 in the DESI Legacy Surveys DR10 catalog, and our observed optical counterpart appears brighter than the host galaxy, though this measurement lacks template subtraction. Given the host redshift z=0.456 (Quirola-Vasquez et al., GCN 38126; see also Adami et al., GCN 38122), the current r-band absolute magnitude of about -20.45 (after Galactic foreground extinction correction) for this optical counterpart indicating it may be an afterglow candidate. View this GCN Circular online at https://gcn.nasa.gov/circulars/38131. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36100] GRB 241025A: radio detection with the VLA
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38130 SUBJECT: GRB 241025A: radio detection with the VLA DATE: 24/11/08 16:21:52 GMT FROM: Stefano Giarratana at INAF-OAB <s.giarratana(a)ira.inaf.it> S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.), N. Omodei (Stanford Univ.), O. S. Salafia (INAF-OAB) At 19:11:50 UT on 2024 Oct 25 (T_mid = 0.76 days post-burst) the Karl G. Jansky VLA observed the field of GRB 241025A (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860; SVOM team, GCN 37863; Li et al., GCN 37864; Svinkin et al., GCN 37927) in three bands, with central frequencies of 6, 10 and 15 GHz. The standard 3C286 was used as bandpass and flux density calibrator, while J2344+8226 was used as phase calibrator. From a preliminary analysis, an unresolved radio source is clearly detected at a position (J2000): RA: 22:14:36.859 +- 0.001 Dec: +83:34:32.27 +- 0.02 consistent with the optical (Ambrosi et al., GCN 37859; Klingler et al., GCN 37919) and X-ray (Goad et al., GCN 37868) position of the transient. The preliminary analysis yields the following results: ============================================================= T_mid Freq Peak r.m.s. Beam PA [days] [GHz] [uJy/b] [uJy/b] [arcsec^2] [deg] ============================================================= 0.76 6 51 7 0.65x0.27 -71 0.76 10 119 8 0.35x0.17 -78 0.76 15 163 8 0.24x0.12 -65 ============================================================= No source is detected with a >3sigma confidence at the aforementioned position in previous radio surveys (FIRST, NVSS, VLASS), all of which have r.m.s. noise levels above 100 uJy/b. We would like to thank the staff of the VLA for approving, executing, and processing the observations. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. These observations were carried out as part of project SF171028, approved in the framework of the Fermi - NRAO joint program agreement. View this GCN Circular online at https://gcn.nasa.gov/circulars/38130. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36099] GRB 241104A: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38129 SUBJECT: GRB 241104A: CALET Gamma-Ray Burst Monitor detection DATE: 24/11/08 15:27:54 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> T. Tamura (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 241104A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 38075; Detection and localization by SVOM/ECLAIRs: Schanne et al., GCN Circ. 38078; EP detection of GRB 241104A X-ray emission: Zhou et al., GCN Circ. 38081; SVOM/GRM observation: Zhang et al., GCN Circ. 38082) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 18:30:15.957 UTC on 04 November 2024 (https://cgbm.calet.jp/cgbm_trigger/flight/1414780091/index.html). The burst signal was seen by only the SGM detector. Because of a problem with the ground alert processing script, the GCN notice was not distributed automatically for this event. The burst light curve shows a multi-peaked structure that starts at T-0.6 sec, peaks at T+2.6 sec, and ends at T+5.1 sec. The T90 and T50 durations measured by the SGM data are 5.0 +/- 0.4 sec and 3.3 +/- 0.5 sec (40-1000 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1414780091/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University. View this GCN Circular online at https://gcn.nasa.gov/circulars/38129. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36098] EP241107a: AKO Optical Afterglow Follow-Up Observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38128 SUBJECT: EP241107a: AKO Optical Afterglow Follow-Up Observations DATE: 24/11/08 13:12:05 GMT FROM: Mohammad Odeh at Al Khatim Observatory M44 <mshodeh(a)gmail.com> Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International Astronomical Center in Abu Dhabi, UAE), and Shaikha Alshamsi, Nuha Manal Pattani, and Nidhal Guessoum (American University of Sharjah, UAE), report: Following up on our first observation (GCN 38115) of the field of EP241107a (detected by EP-WXT, Zhou et al., GCN38112), we report observations of the source over three time periods starting on 07 November 2024 at 15:40 (UT), 90 minutes from the trigger, with our 0.36m f/7.7 robotic telescope. We obtained 30x180-sec exposures in Ic filter of the uncatalogued object detected at R.A. (J2000): 02:20:02.45, Dec. (J2000): +03:20:02.2. The following table summarizes the results of the images, calculated using the Atlas catalog as a reference: ----------------------------------------------------------------- ObsTime (mid), Exposure (sec), Filter, Mag ----------------------------------------------------------------- 2024-11-07T15:55:21Z, 10 x 180s (stacked), Ic, 17.95 +/- 0.19 2024-11-07T16:26:29Z, 10 x 180s (stacked), Ic, 18.11 +/- 0.24 2024-11-07T16:57:37Z, 10 x 180s (stacked), Ic, 18.48 +/- 0.25 ----------------------------------------------------------------- The magnitudes are not corrected for galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38128. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36097] EP241107a: GSP detects optical counterpart
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38127 SUBJECT: EP241107a: GSP detects optical counterpart DATE: 24/11/08 11:20:01 GMT FROM: Wenxiong Li <liwenxiong1992(a)gmail.com> W. X. Li, S. J. Xue (NAOC), M. Andrews, J. Farah, D. A. Howell, M. Newsome, E. Padilla Gonzalez, C. McCully, and G. Terreran (Las Cumbres Observatory), on behalf of a larger collaboration, report: Following the detection of the fast X-ray transient EP241107a by the Einstein Probe (Zhou et al., GCN 38112) with the Sinistro instrument mounted on the 1-m telescope of the LCO, we initiated observations of the fast X-ray transient location starting on 2024 November 7 at 19:13 UT (~5 hours after the EP/WXT trigger) in the i band. These observations were conducted using the 1-meter telescope at the Las Cumbres Observatory node located at Sutherland in South Africa. The optical counterpart (Odeh et al., GCN 38115; Kang et al., GCN 38116; Mohan et al., GCN 38118; Busmann et al., GCN 38120) was detected in the co-added images with i = 19.4+-0.1. These observations were taken as part of the Global Supernova Project. View this GCN Circular online at https://gcn.nasa.gov/circulars/38127. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36096] EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38126 SUBJECT: EP241107a: Gemini-South spectroscopic confirmation (z = 0.456) DATE: 24/11/08 08:46:39 GMT FROM: Jonathan Quirola at Radboud University <jaquirola1990(a)gmail.com> J. Quirola-Vasquez (Radboud Univ.), F.E. Bauer (PUC), P.G. Jonker (Radboud Univ.), D.B. Malesani (DAWN/NBI & Radboud Univ.), A.J. Levan (Radboud), report for a larger collaboration: We observed the optical counterpart of EP241107a (Odeh et al., GCN 3 8115; Kang et al., GCN 38116; Lipunov et al., GCN 38117; Mohan et al., GCN 38118; Busmann et al., GCN 38120) detected by EP-WXT (Zhou et al., GCN 38112) using the Gemini-South (GS) telescope equipped with the Gemini Multi-Object Spectrograph (GMOS) instrument, and the grating R400. We started observing the target on 2024-11-08 03:05:08.6 UT (i.e., ~12.9 hr after the X-ray trigger), taking four spectra (4x800 s) and covering the wavelength range ~5000-9500 AA. A continuum is clearly detected, as well as several emission lines, which we interpret as [O III] 4959,5007, Hbeta, and a marginal detection of [O II] 3727, also mentioned by Adami et al. (GCN 38122), all at a common redshift z = 0.456. This value is broadly consistent with the one reported by Adami et al. (GCN 38122) and the photometric redshift of the host galaxy reported in the Legacy catalog z= 0.523+-0.106 (Zhou et al. 2021). We acknowledge expert support from the Gemini South staff. View this GCN Circular online at https://gcn.nasa.gov/circulars/38126. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36095] EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38126 SUBJECT: EP241107a: Gemini-South spectroscopic confirmation (z = 0.456) DATE: 24/11/08 08:46:39 GMT FROM: Jonathan Quirola at Radboud University <jaquirola1990(a)gmail.com> J. Quirola-Vasquez (Radboud Univ.), F.E. Bauer (PUC), P.G. Jonker (Radboud Univ.), D.B. Malesani (DAWN/NBI & Radboud Univ.), A.J. Levan (Radboud), report for a larger collaboration: We observed the optical counterpart of EP241107a (Odeh et al., GCN 3 8115; Kang et al., GCN 38116; Lipunov et al., GCN 38117; Mohan et al., GCN 38118; Busmann et al., GCN 38120) detected by EP-WXT (Zhou et al., GCN 38112) using the Gemini-South (GS) telescope equipped with the Gemini Multi-Object Spectrograph (GMOS) instrument, and the grating R400. We started observing the target on 2024-11-08 03:05:08.6 UT (i.e., ~12.9 hr after the X-ray trigger), taking four spectra (4x800 s) and covering the wavelength range ~5000-9500 AA. A continuum is clearly detected, as well as several emission lines, which we interpret as [O III] 4959,5007, Hbeta, and a marginal detection of [O II] 3727, also mentioned by Adami et al. (GCN 38122), all at a common redshift z = 0.456. This value is broadly consistent with the one reported by Adami et al. (GCN 38122) and the photometric redshift of the host galaxy reported in the Legacy catalog z= 0.523+-0.106 (Zhou et al. 2021). We acknowledge expert support from the Gemini South staff. View this GCN Circular online at https://gcn.nasa.gov/circulars/38126. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36094] GRB 241107A: SVOM/GRM detection of a short burst
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38125 SUBJECT: GRB 241107A: SVOM/GRM detection of a short burst DATE: 24/11/08 08:35:11 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Wen-Jun Tan, Shi-Jie Zheng, Yong-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zhang, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao, Chao Zheng (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP), JeanLuc Attéia (IRAP) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: During the commissioning phase, the SVOM/GRM was triggered in-flight by GRB 241107A at 2024-11-07T23:30:00.100 UT (T0). The real-time alert data and light curves of SVOM/GRM were downlinked to the ground through the VHF system with low latency. The GRM light curve shows that this burst consists of a single pulse followed by a tail with a T90 of 0.5 +0.1/-0.1 s. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Chen-Wei Wang (IHEP)(cwwang(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38125. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36093] GRB 241105A: EP-FXT follow-up observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38124 SUBJECT: GRB 241105A: EP-FXT follow-up observations DATE: 24/11/08 06:40:17 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> H. Zhou (PMO, CAS), R.-Z. Li (YNAO, CAS), X. L. Chen, K. Chatterjee (YNU), S. Q. Jiang, T. Zhao, D. Y. Li, W. Chen, C. C. Jin, H. W. Pan (NAO,CAS), E. Troja (U Rome), X. F. Wu (PMO, CAS), P. Jonker (Radboud Univ.) report on behalf of the Einstein Probe team: The Follow-up X-ray telescope (FXT) on board the Einstein Probe mission performed two follow-up observations of GRB 241105A (Fermi GBM team, GCN 38085; DeLaunay et al., GCN 38091; Frederiks et al., GCN 38103), and detected a fading uncataloged X-ray source. The EP-FXT loaction of the X-ray source is consistent with the location of the optical counterpart of GRB 241105A (Julakanti et al., GCN 38088; Izzo et al., GCN 38097; SVOM/VT team, GCN 38099; Hu et al., GCN 38106). The results are reported: +--------------------------------------------------------------------------------------------------------+ T_start (UTC) | T_end (UTC) | Exposure (s) | T_mid - T_0 (h) | Flux (0.5-10keV, erg/s/cm^2) +--------------------------------------------------------------------------------------------------------+ 2024-11-06T13:40:26 | 2024-11-06T14:28:44 | 2894 | 22.0 | (1.51+/-0.31)E-13 2024-11-07T04:05:45 | 2024-11-07T08:05:40 | 7966 | 38.0 | (3.79+/-0.50)E-14 +--------------------------------------------------------------------------------------------------------+ The derived temporal decay index is 2.5 +/- 0.4, which is consistent with the value reported by the Swift-XRT team (Kennea et al., GCN 38098). Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/38124. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36091] GRB 241105A: SVOM/GRM observation
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38123 SUBJECT: GRB 241105A: SVOM/GRM observation DATE: 24/11/08 06:34:21 GMT FROM: zhengchao_astro(a)foxmail.com SVOM/GRM team: Chao Zheng, Chen-Wei Wang, Shi-Jie Zheng, Yong-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zhang, Wen-Jun Tan, Jin-Peng Zhang, Yue Wang, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP), JeanLuc Attéia (IRAP) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) Report on behalf of the SVOM team: During the commissioning phase, the SVOM/GRM was triggered in-flight by GRB 241105A (SVOM trigger reference: sb24110502) at 2024-11-05T16:06:05.00 UT (T0), which was also observed by Fermi/GBM (Fermi GBM Team, GCN 38085), Konus-Wind (D. Frederiks et al., GCN 38103), and Swift/BAT (J. DeLaunay et al., GCN 38108). The real-time alert data and light curves of SVOM/GRM were downlinked to the ground through the VHF system with low latency. With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of a short single pulse with a duration of about 2 s and a weaker extended emission with a duration of about 40 s. The significance of extended emission observed by GRD03 is about 3.6 sigma from T0+2 to T0+42 s. The initial pulse spectrum from T0-0.5 to T0+1.7 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.93 +/- 0.54 and the cutoff energy, parameterized as Epeak, is 214 +/- 59 keV. The event fluence (10-1000 keV) in this time interval is (1.05 +/- 0.19)E-06 erg/cm^2. The extended emission spectrum from T0+1.7 to T0+42 s is best fit by a power law function. The power law index is -1.63 +/- 0.18. The event fluence (10-1000 keV) in this time interval is (1.76 +/- 0.31)E-07 erg/cm^2. The time-integrate spectrum from T0-0.5 to T0+42 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.23 +/- 0.52 and the cutoff energy, parameterized as Epeak, is 455 +/- 335 keV. The event fluence (10-1000 keV) in this time interval is (2.13 +/- 0.48)E-07 erg/cm^2. According to the redshift z=2.702 (Izzo et al., GCN 38097), we estimate the burst isotropic equivalent radiated energy, parameterized as Eiso, is (1.76 +/- 0.76)E+53 erg (1-10000 keV). The burst position (from Swift/BAT) was outside the SVOM/ECLAIRs field of view at trigger time. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Chao Zheng (zhengchao97(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38123. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36092] GRB 241105A: SVOM/GRM observation
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38123 SUBJECT: GRB 241105A: SVOM/GRM observation DATE: 24/11/08 06:34:21 GMT FROM: zhengchao_astro(a)foxmail.com SVOM/GRM team: Chao Zheng, Chen-Wei Wang, Shi-Jie Zheng, Yong-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zhang, Wen-Jun Tan, Jin-Peng Zhang, Yue Wang, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP), JeanLuc Attéia (IRAP) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) Report on behalf of the SVOM team: During the commissioning phase, the SVOM/GRM was triggered in-flight by GRB 241105A (SVOM trigger reference: sb24110502) at 2024-11-05T16:06:05.00 UT (T0), which was also observed by Fermi/GBM (Fermi GBM Team, GCN 38085), Konus-Wind (D. Frederiks et al., GCN 38103), and Swift/BAT (J. DeLaunay et al., GCN 38108). The real-time alert data and light curves of SVOM/GRM were downlinked to the ground through the VHF system with low latency. With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of a short single pulse with a duration of about 2 s and a weaker extended emission with a duration of about 40 s. The significance of extended emission observed by GRD03 is about 3.6 sigma from T0+2 to T0+42 s. The initial pulse spectrum from T0-0.5 to T0+1.7 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.93 +/- 0.54 and the cutoff energy, parameterized as Epeak, is 214 +/- 59 keV. The event fluence (10-1000 keV) in this time interval is (1.05 +/- 0.19)E-06 erg/cm^2. The extended emission spectrum from T0+1.7 to T0+42 s is best fit by a power law function. The power law index is -1.63 +/- 0.18. The event fluence (10-1000 keV) in this time interval is (1.76 +/- 0.31)E-07 erg/cm^2. The time-integrate spectrum from T0-0.5 to T0+42 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.23 +/- 0.52 and the cutoff energy, parameterized as Epeak, is 455 +/- 335 keV. The event fluence (10-1000 keV) in this time interval is (2.13 +/- 0.48)E-07 erg/cm^2. According to the redshift z=2.702 (Izzo et al., GCN 38097), we estimate the burst isotropic equivalent radiated energy, parameterized as Eiso, is (1.76 +/- 0.76)E+53 erg (1-10000 keV). The burst position (from Swift/BAT) was outside the SVOM/ECLAIRs field of view at trigger time. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Chao Zheng (zhengchao97(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38123. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36090] EP241107a: OHP/T193 photometric and spectroscopic observations
by GCN Circulars 08 Nov '24

08 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38122 SUBJECT: EP241107a: OHP/T193 photometric and spectroscopic observations DATE: 24/11/08 01:33:32 GMT FROM: Christophe Adami at LAM <christophe.adami(a)lam.fr> C. Adami (LAM/Pytheas/AMU), M. Dennefeld (IAP/CNRS/Sorbonne U.), A. Coleiro (APC), S. Basa (LAM/Pytheas/AMU), E. Le Floc'h (CEA Paris-Saclay) report on behalf of a larger collaboration We first performed imaging of the field of EP241107a (Zhou et al. GCN38112, Odeh et al. GCN 38115, Chao Wu et al. GCN 38116, Lipunov et al. GCN 38117, Mohan et al. GCN 38118, Busmann et al. GCN 38120) with MISTRAL mounted on the 1.93 m telescope at Observatoire du Haute Provence (OHP, France). The imaging observations consisted of 3x300s exposures in r-band. We have a very clear detection of the transient object. Using as reference field stars from the Pan-STARRS catalogue in a 1 arcmin radius around the target, we determine a preliminar magnitude of r(AB) = 19.8 +/- 0.05 mag at a mean date of 2024-11-07T21:15 UT, ~7 hours after the burst, in good agreement with other reported measurements. We immediately after took two spectra of the object using the MISTRAL blue grism (end of data collection at 2024-11-07T22:40). Our spectra cover the wavelength range 4200-8100A at a resolution of R~700 and consist of one exposure of 900 seconds and an exposure of 1800sec. A red continuum is clearly detected from 5200A onwards, but with low signal to noise ratio. A single emission line can be marginally seen at ~5350A observed wavelength on the 2D spectrum. If identified as [OII] 3727A, this would imply a redshift of 0.4355 for the galaxy suggested by Odeh et al. This however needs confirmation, as other emission lines then expected would fall in regions polluted by night sky emission. We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean Pierre Troncin for the MISTRAL observations and Neda Heidari. View this GCN Circular online at https://gcn.nasa.gov/circulars/38122. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36089] GRB 241105a: PRIME near-infrared upper limits
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38121 SUBJECT: GRB 241105a: PRIME near-infrared upper limits DATE: 24/11/07 21:40:20 GMT FROM: Joe Durbak at UMD <gcn.joedurbak(a)gmail.com> J. Durbak (UMD), O. Guiffreda (UMD), S. Atri (U Rome), A. S. Kutyrev (NASA/GSFC), E. Troja (U Rome), S. B. Cenko (NASA/GSFC) Following the Fermi GBM detection (GCN 38085), we observed the transient field in J-filter with PRIME ~31 hours after Fermi GBM detection. At the counterpart positions reported by GOTO (GCN 38088), Swift XRT (GCN 38098), and Swift UVOT(GCN 38110), we detect no uncatalogued sources in J-band. Using nearby VISTA Hemispherical Survey (VHS) stars for preliminary calibration we derive a limiting magnitude of <21.2 AB, not corrected for Galactic extinction. PRIME is a 1.8m telescope with 1.56 square degree FOV (0.5 arcsec/pixel) located in Sutherland, South Africa at the South African Astronomical Observatory (SAAO) (Kutyrev et al. 2023, Yama et al. 2023, Durbak et al. 2024). We thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/38121. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36088] EP241107a: FTW Optical and NIR observations of the optical counterpart
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38120 SUBJECT: EP241107a: FTW Optical and NIR observations of the optical counterpart DATE: 24/11/07 21:38:22 GMT FROM: Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann(a)physik.lmu.de> Malte Busmann (LMU), Daniel Gruen (LMU), Brendan O’Connor (Carnegie Mellon U.) and Antonella Palmese (Carnegie Mellon U.) report: We observed the counterpart of EP241107a (Zhou et al., GCN 38112; Odeh et al.; GCN 38115; Kang et al.; GCN 38116; Lipunov et al.; GCN 38117; Mohan et al.; GCN 38118) with the Three Channel Imager (3KK) at the Fraunhofer Telescope Wendelstein (FTW) in the r, i and J band simultaneously for 14 x 180 s starting at 2024-11-07T20:29:01 UT (6.31 h = 0.26 days after the trigger). We detect the counterpart at r = (19.65 +/- 0.01) mag i = (19.40 +/- 0.01) mag J = (18.71 +/- 0.01) mag The r- and i-band magnitudes are calibrated against the PS1 catalog and the J-band is calibrated with the 2MASS catalog. All magnitudes are provided in the AB system and not corrected for Galactic extinction. We thank the staff of the Wendelstein Observatory for obtaining these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/38120. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36087] GRB 241105A: ePESSTO+ NTT optical afterglow detection
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38119 SUBJECT: GRB 241105A: ePESSTO+ NTT optical afterglow detection DATE: 24/11/07 21:17:07 GMT FROM: Paolo D'Avanzo at INAF - OAB <paolo.davanzo(a)inaf.it> K. Tsalapatas, Y. Hu, P. J. Pessi (Stockholm), P. D'Avanzo (INAF-OAB), D. B. Malesani (DAWN/NBI and Radboud univ.), A. Gangopadhyay, A. Singh, A. Gkini, J. Sollerman, S. Barmentloo (Stockholm), T. Kravtsov (Turku), G. Pignata (UTA), J. Anderson (ESO), T.-W. Chen (NCU), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), T. Müller Bravo (Trinity), O. Yaron (Weizmann), D. Young (QUB), S. Benetti (INAF), E. Zimmerman (Weizmann), Asaf Horowicz (Weizmann), J. Tonry, L. Denneau, H. Weiland, A. Lawrence, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), A. Jordan, V. Suc (UAI, Obstech), S. J. Smartt (Oxford/QUB), K. W. Smith, S. Srivastav, D. R. Young, M. Fulton, M. McCollum, T. Moore, M. Nicholl, J. Weston (QUB), L. Shingles (GSI/QUB), L. Rhodes (Oxford), J. Sommer (LMU/QUB), A. Rest (STScI), C. Stubbs (Harvard) report: We observed the field of GRB 241105A (Fermi GBM team, GCN 38085; DeLaunay et al., GCN 38091; Frederiks et al., GCN 38103) under the advanced Public ESO Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40; http://www.pessto.org). The observations were performed with the ESO New Technology Telescope (NTT) at La Silla equipped with the EFOSC2 instrument in imaging mode, starting on 2024 Nov 06 at 03:21:27 UT (i.e. about 1.47 days after the burst) using the r and z gunn filters. The optical afterglow (Julakanti et al., GCN 38088) is clearly detected in both bands. From preliminary photometry, we estimate a magnitude of r = 22.4 +/- 0.1 (AB; calibrated against the ATLAS REFCAT2 catalogue; Tonry et al. 2018). This result is in agreement with the report from Dichiara et al. (GCN 38111). View this GCN Circular online at https://gcn.nasa.gov/circulars/38119. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36086] EP241107a: GIT optical observations
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38118 SUBJECT: EP241107a: GIT optical observations DATE: 24/11/07 21:14:35 GMT FROM: V. Swain at IIT Bombay <vishwajeet.s(a)iitb.ac.in> T. Mohan, V. Swain, A. P. Saikia, R. Kumar, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed the field of EP241107a (Zhou et al., GCN 38112) with 0.7m GROWTH-India Telescope (GIT). We started the observation at 2024-11-07 17:43:35 UT, i.e., 3.55 hours after the EP-WXT trigger. We obtained multiple exposures of 300 seconds in the g', r', and i' filters. We detected the optical afterglow in our individual as well as stacked images at position reported by Odeh et al., GCN 38115 and also observed by SVOM/C-GFT team GCN 38116. The photometry results follow as: ---------------------------------------------------------------- | MJD (mid) | Filter | Total Exposure (s) | Magnitude (AB) | | ------------- | ------ | ------------------ | -------------- | | 60621.751482 | r' | 1x300 | 19.42 +/- 0.07 | | 60621.762569 | g' | 1x300 | 19.86 +/- 0.1 | | 60621.777315 | i' | 3x300 | 19.17 +/- 0.06 | ---------------------------------------------------------------- Based on our results and other reported detections, source is red and decaying. The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/. View this GCN Circular online at https://gcn.nasa.gov/circulars/38118. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36085] EP241107a: Global MASTER-Net observations report
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38117 SUBJECT: EP241107a: Global MASTER-Net observations report DATE: 24/11/07 17:54:24 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the EP241107a ( EP Team et al., GCN 38112) errorbox 8596 sec after notice time and 12823 sec after trigger time at 2024-11-07 17:44:06 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 59 deg. The sun altitude is -36.0 deg. The galactic latitude b = -52 deg., longitude l = 162 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2661310 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 12854 | 2024-11-07 17:44:06 | MASTER-Tavrida | (02h 22m 58.26s , +03d 16m 49.2s) | C | 60 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38117. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36084] EP241107a: SVOM/C-GFT optical observations
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38116 SUBJECT: EP241107a: SVOM/C-GFT optical observations DATE: 24/11/07 17:35:15 GMT FROM: Chao Wu at NAOC <cwu(a)nao.cas.cn> SVOM/C-GFT team: Zhe Kang (CHO), Chao WU (NAOC), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC),Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) We started to observe the field of EP241107a detected by EP-WXT (Zhou et al. GCN 38112) on 2024-11-07T14:15:49 UT, ~ 5.42 mins after the trigger with C-GFT in the commissioning phase. A series of images were obtained with exposure time of 10s. The uncatalogued object reported by Odeh et al. (GCN 38115) was detected in stacked image with mag_i = 17.12 +/-0.10 at ~5.7 mins after the trigger. There is no obviously decay found during ~22 mins observation. The photometry was calibrated with nearby PS1 star. We thank the observation assistant Yinghuai Hao and Chunlei Guo at Jilin observatory for their excellent support. Chinese Ground Follow-up Telescope of SVOM mission is located at Jilin, Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope. View this GCN Circular online at https://gcn.nasa.gov/circulars/38116. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36083] EP241107a: AKO Optical Afterglow Detection
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38115 SUBJECT: EP241107a: AKO Optical Afterglow Detection DATE: 24/11/07 16:22:43 GMT FROM: Mohammad Odeh at Al Khatim Observatory M44 <mshodeh(a)gmail.com> Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International Astronomical Center in Abu Dhabi, UAE), and Shaikha Alshamsi, Nuha Manal Pattani, and Nidhal Guessoum (American University of Sharjah, UAE), report: We observed the field of EP241107a detected by EP-WXT (Zhou et al., GCN 38112), with our 0.36m f/7.7 robotic telescope. The observation started on 07 November 2024 at 15:40 (UT), 90 minutes from the trigger. We obtained multiple 180-sec exposures in Ic filter. We detected uncatalogued object at: R.A. (J2000): 02:20:02.45 Dec. (J2000): +03:20:02.2 The following observation was calculated using Atlas catalogue as a reference: ---------------------------------------------------------------------------- - ObsTime (mid), Exposure (sec), Filter, Mag ---------------------------------------------------------------------------- - 2024-11-07T15:53:50Z, 9x180s (stacked), Ic, 17.85 +/- 0.18 ---------------------------------------------------------------------------- - Using The Dark Energy Survey (DES) catalogue, there is a galaxy at this location of magnitude i=22.6, which could be the hosting galaxy. The magnitude is not corrected for galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38115. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36082] GRB 241025A: LBT optical observations
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38114 SUBJECT: GRB 241025A: LBT optical observations DATE: 24/11/07 15:41:56 GMT FROM: Andrea Rossi at INAF <andrea.rossi(a)inaf.it> A. Rossi, E. Maiorano (INAF/OAS), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Melandri, D. Paris, and E. Marini (INAF-OAR), report on behalf of a larger collaboration: We observed the optical counterpart of GRB 241025A (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860; Wang et al., GCN 37863; Li et al., GCN 37864) with the LBC camera mounted on LBT (Mt. Graham, AZ, USA) in the r', i', and z' bands with approximate midtime 04:54:00 UT on 2024-10-28, or 3.14 days after the burst. Observations were performed under an average seeing of ~1.2" but with a few passing cirrus. The optical afterglow (Ambrosi et al., GCN 37859; Jiang et al., GCN 37862; Pereyra et al., GCN 37865; Xu et al., GCN 37866; SVOM/VT team, GCN 37871; Abdi et al., GCN 37882; Watson et al., GCN 37889; Mohan et al., GCN 37890; Vinko et al., GCN 37891; Gupta et al., GCN 37893; Pankov et al., GCN 37912; Moskvitin and Spiridonova, GCN 37914 and 37923; Klingler and Ambrosi, GCN 37919; Wang et al., GCN 37926) is well detected in all bands. We measure a preliminary AB magnitude of r' = 23.6+-0.1, calibrated against Pan-STARRS field stars, and not corrected for the foreground Galactic extinction. We acknowledge excellent support from the LBTO and LBT-INAF staff, particularly O. Kuhn and R. Ansaldi. View this GCN Circular online at https://gcn.nasa.gov/circulars/38114. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36081] GRB241105A: Gemini-South Optical Afterglow Detection
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38113 SUBJECT: GRB241105A: Gemini-South Optical Afterglow Detection DATE: 24/11/07 15:40:50 GMT FROM: Jillian Rastinejad at Northwestern Univ. <jillianrastinejad2024(a)u.northwestern.edu> J. Rastinejad, C. Kilpatrick, W. Fong (Northwestern) report on behalf of a larger collaboration: We observed the location of the X-ray (Kennea et al. GCN 38098) and optical (Julakanti et al., GCN 38088) counterparts of GRB 241105A (Fermi GBM Team GCN 38085, DeLaunay et al. GCN 38091, Frederiks et al. GCN 38103) with the Gemini Multi-Object Spectrograph (GMOS) mounted on Gemini-South under Program GS-2024B-Q-108 (PI: Fong). We obtained 8x120-sec imaging in r-band at a mid-time of 2024-11-07 01:44:56.1 UT (1.4 days post-burst), at a median airmass of 1.6. We clearly detect the optical afterglow. Calibrated to SkyMapper, we measure a preliminary brightness of r~21.7 AB mag at seeing < 1.1'', not corrected for Galactic extinction nor emission from the underlying galaxy (Izzo et al. 38097). Compared to the measurement of r=19.2 +/- 0.2 AB mag at 0.4 days reported by Hu et al. (GCN 38106), our observation indicates a rapid rate of decay (Fopt ~ t^-1.8). This decline rate is potentially contaminated by the host galaxy, and the true decline rate may be steeper. While the inferred magnitude differs by ~0.8 mag from the R-band measurement of Dichiara et al. (GCN 38111), we deduce similar decline rates in slightly different filters. Further observations are planned to monitor the variability of the source. We thank Jennifer Andrews and additional Gemini staff for the rapid planning and execution of these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/38113. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36080] EP241107a: EP on-board trigger and autonomous follow-up observation
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38112 SUBJECT: EP241107a: EP on-board trigger and autonomous follow-up observation DATE: 24/11/07 15:20:23 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> H. Zhou (PMO, CAS), R.-Z. Li (YNAO, CAS), W. Chen, T. Zhao (NAO,CAS), X. L. Chen (YNU), K. Chatterjee (YNU) and H. W. Pan (NAO,CAS) report on behalf of the Einstein Probe team: We report on the detection of an X-ray transient detected by EP-WXT, EP241107a, which triggered the on-board processing unit at 2024-11-07T14:10:23Z (UTC) (trigger ID: 01709118091). The trigger flux is estimated to be around 1e-10 erg/s/cm^2 in 0.5-4 keV. An autonomous observation on the X-ray transient was performed by the EP-FXT about 5 minutes later, which detected an X-ray source at R.A. = 35.0085 deg, DEC = 3.3329 deg (J2000) with an uncertainty of about 10 arcsecs (radius, 90% C.L. statistical and systematic), consistent with the position of the WXT transient within the uncertainties. In the image of DESI Legacy Imaging Surveys, there is a star (effective temperature is about 3600 K, from GAIA DR3) and a galaxy within the EP-FXT error circle of EP241107a. Hence, the possibility that EP241107a is a stellar flare event cannot be ruled out. Further follow-up observations are encouraged to explore the orgin of EP241107a. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/38112. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36079] GRB 241105A: VLT/FORS2 optical afterglow rapid fading
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38111 SUBJECT: GRB 241105A: VLT/FORS2 optical afterglow rapid fading DATE: 24/11/07 14:59:37 GMT FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra(a)roma2.infn.it> Simone Dichiara (PSU), Eleonora Troja (U Rome), Rosa L. Becerra (U Rome), Yu-Han Yang (U Rome) report: We observed the field of GRB 241105A (Fermi GBM team, GCN 38085; DeLaunay et al., GCN 38091; Konus-Wind team, GCN 38103) with the FORS2 imager on the ESO VLT UT1 (Antu). Observations began 1.5 days after the trigger and were carried out in the R and z filters through good seeing conditions (0.8"). We detect the optical counterpart (Julakanti et al., GCN 38088) at a preliminary magnitude R ~22.5 AB mag calibrated using nearby stars in the Legacy Survey DR10 (Dey et al. 2019). Compared with earlier optical detections (Julakanti et al., GCN 38088; SVOM/VT team, GCN 38099; Izzo et al. GCN 38097; Hu et al., GCN 38106), our observations show a rapid decline of the afterglow brightness, consistent with a power-law of slope ~-1.7. Further observations are planned. We thank the staff at the VLT, especially Maria Jose Rain, for the rapid execution of these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/38111. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36078] GRB 241105A: Swift/UVOT Detection
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38110 SUBJECT: GRB 241105A: Swift/UVOT Detection DATE: 24/11/07 13:18:53 GMT FROM: Mike Siegel at PSU/Swift MOC <mhs18(a)psu.edu> M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 241105A 38.4 ks after the Fermi trigger (GCN Circ. 38085). A faint fading source is detected consistent with the XRT position (Kennea et al., GCN Circ. 38098) and the reported optical counterparts (Julakanti et al., GCN Circ. 38088, Izzo, GCN. Circ. 38097, Wei et al., GCN Circ. 38099, Hu et al., GCN Circ 38106). The preliminary UVOT position is: RA (J2000) = 04:24:58.96 = 66.24568 (deg.) Dec (J2000) = -49:45:09.8 = -49.75271 (deg.) with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence). Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 38363 67383 4551 21.46+/-0.11 white 90644 106641 4612 >22.76 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.011 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/38110. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36077] EP241101a: CrAO ZTSH optical observations
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38109 SUBJECT: EP241101a: CrAO ZTSH optical observations DATE: 24/11/07 03:48:50 GMT FROM: Alexei Pozanenko at IKI, Moscow <grb.alex(a)gmail.com> N. Pankov (HSE, IKI), A. Pozanenko (IKI), V. Rumyantsev (CrAO) report on behalf of GRB-IKI-FuN collaboration: We observed the EP241101a detected by EP-WXT (Liang et al., GCN 38039) with the 2.6-meter ZTSh telescope of CrAO in the R-filter. The observations were carried out on 02.11.2024 and 03.11.2024. We found several OT candidates entire the EP-WXT localization area. In particular the source (PS1 catalog PSO J037.7952+22.7485) reported by Busmann et al., GCN 38064 and the source reported by Adami et al., GCN 38060 were also marked as candidates in our preliminary analysis. And we do not find any sources within the enhanced localization area of EP-FXT (Wu et al., GCN 38073). Preliminary photometry of the sources and upper limits are the following: Date UT start TO+ Exp. Filter GCN#38064 GCN#38064 UL(3) (mid, days) (s) OT OT 2024-11-02 23:59:22 1.03548 46x120 R 19.98+-0.05 n/d 21.0 2024-11-03 21:18:54 1.91711 36x120 R 20.47+-0.02 21.88+-0.04 22.0 Photometry is calibrated using nearby USNO-B1.0 stars (R2 magnitude). Based on our observations and previously reported candidates, we cannot suggest an obvious candidate for OT EP341101a. View this GCN Circular online at https://gcn.nasa.gov/circulars/38109. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36076] GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
by GCN Circulars 07 Nov '24

07 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38108 SUBJECT: GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission DATE: 24/11/07 00:52:08 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT GUANO detected and localized GRB 241105A (GCN 38091). GRB 241105A was also detected by Fermi/GBM (GCN 38104), GOTO (GCN 38088), Swift-XRT (GCN 38098), SVOM/VT (GCN 38099), VLT/FORS2 (GCN 38097), and Konus-Wind (GCN 38103). The burst was detected at a partial coding fraction of 14%. The mask-weighted light curve shows a short, strong pulse with a duration of ~2 s followed by a longer extended emission with a duration of ~75 s. Consistent with what was observed by both Fermi/GBM (GCN 38104) and Konus-Wind (GCN 38103). T90 (15 - 350 keV) is 72.8 s +/- 9.7 s . The time-average spectrum over T100 from T0 - 0.5 s to T0 + 77.8 s is best fit by a simple power-law with an index of 1.33 +/- 0.20. The 15 - 150 keV fluence is 2.5 +/- 0.3 x 10^-6 erg/cm2. Both the initial spike and the extended emission are best fit by simple power-laws with consistent spectral indices. ~77% of the fluence is contained in the extended emission. The initial spike (T0 - 1.1 s to T0 + 1.3 s) has a best fit spectral index of 1.65 +/- 0.20 with a 15 - 150 keV fluence of 5.6 +/- 0.7 x 10^-7 erg/cm2. The extended emission (T0 + 1.3 s to T0 + 77.8 s) has a best fit spectral index of 1.26 +/- 0.25 with a 15 - 150 keV fluence of 1.9 +/- 0.3 x 10^-6 erg/cm2. View this GCN Circular online at https://gcn.nasa.gov/circulars/38108. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36075] GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38107 SUBJECT: GRB 241030A: optical afterglow detection from the INAF Asiago Observatory DATE: 24/11/06 22:38:03 GMT FROM: Youdong HU at INAF-OAB <huyoudong072(a)hotmail.com> A. Reguitti (INAF-OAB / INAF-OAPd), Y.-D. Hu, M. Ferro, R. Brivio, P. D'Avanzo (INAF-OAB), L. Tomasella (INAF-OAPd), E. Cappellaro (INAF-OAPd), Paolo Ochner (UniPd) and Stefano Fiscale (UniParthenope), report on behalf of the CIBO and of the GRAWITA collaborations: We carried out follow-up optical observations of GRB241030A by Fermi, Swift, SVOM and Konus-Wind (Fermi GBM team, GCNC 37955; Klingler et al., GCNC 37956; Beardmore et al., GCN 37962; SVOM/GRM team, GCNC 37972; Ridnaia et al., GCNC 37982; Pillera et al., GCNC 37979) from the INAF-Padova Astronomical Observatory located in Asiago (Italy) with the 67/92 Schmidt telescope starting on 2024-10-30 at 17:47:50UT (~12 hour after trigger) with SDSS-ri filters. In our single exposure, the optical afterglow (Watson et al., GCNC 37957;Fernández-Rodríguez et al., GCNC 37958; Zheng et al., GCNC 37959; An et al., GCNC 37960; Higuchi et al., GCNC 37963; SVOM/VT team, GCNC 37965; Lin et al., GCNC 37966; SVOM/C-GFT team, GCNC 37970; Breeveld et al., GCNC 37974; Lipunov et al., GCNC 37975 37977; Odeh et al., GCNC 37976; Moskvitin et al., GCNC 38016; Busmann et al. GCNC 38019; Schneider et al. GCNC 38021; Li et al. GCNC 38027; Masi et al. GCNC 38031; Moskvitin et al. GCNC 38032; Yan et al. GCNC 38035; TESS Mission, GCNC 38050; Wang et al. GCNC 38055; Pankov et al. GCNC 38105) is clearly detected. From preliminary analysis, we estimated a magnitude of r=19.29+-0.12 mag (AB; calibrated against r band of SDSS catalog). Further observation is under analysis. We thank the staff at Padova Astronomical Observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38107. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36074] GRB 241105A: BOOTES-7 optical detection
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38106 SUBJECT: GRB 241105A: BOOTES-7 optical detection DATE: 24/11/06 21:39:39 GMT FROM: Youdong HU at INAF-OAB <huyoudong072(a)hotmail.com> Y.-D. Hu (INAF-OAB), I. Perez-Garcia, A. J. Castro-Tirado, E. Fernandez-Garcia, S.-Y. Wu, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga), L. Hernandez-Garcia (Univ. de Valparaiso), M. Gritsevich (Univ. of Helsinki), D. R. Xiong (Yunnan Observatories of CAS), B.-B. Zhang (Nanjing Univ.) and A. Maury (Space, San Pedro de Atacama), on behalf of a larger collaboration, report: Following the detection of GRB 241105A by Fermi (Fermi GBM team, GCNC 38085) and Swift (DeLaunay et al. GCNC 38091; Kennea et al., GCNC 38098), we triggered the 0.6m BOOTES-7 robotic telescope at San Pedro de Atacama celestial observations in San Pedro de Atacama (Chile) to observe the burst position on Nov. 6 at 01:58 UT (i.e. ~ 9.9 hrs after trigger). A series of images was obtained with multi-bands. In the co-added image (11 x 60 s, SDSS-r filter), the optical afterglow reported by GOTO (Julakanti et al. GCNC 38088), VLT (Izzo et al., GCNC 38097) and SVOM/VT (Qiu et al., GCNC 38099) is detected with r=19.2+-0.2 mag. We thank the staff at San Pedro de Atacama celestial observations for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38106. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36073] GRB 241030A: Mondy optical observations
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38105 SUBJECT: GRB 241030A: Mondy optical observations DATE: 24/11/06 20:35:06 GMT FROM: Alexei Pozanenko at IKI, Moscow <apozanen(a)iki.rssi.ru> N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP) report on behalf of IKI-GRB-FuN: We continued observations of the optical afterglow (Klingler et. al, GCN 37956; Watson et. al, GCN 37957; Fernández-Rodríguez et. al, GCN 37958; An et. al, GCN 37960; Higuchi et. al, GCN 37963; SVOM/VT commissioning team, GCN 37965; Lin et. al, GCN 37966; SVOM/C-GFT team, GCN 37970; Breeveld & Klingler, GCN 37974; Odeh et. al, GCN 37976; Méndez-Lapido et. al, GCN 37993; Antier et. al, GCN 38000; Moskvitin & Goranskij, GCN 38016; Busmann et. al, GCN 38019; Schneider et. al, GCN 38021; Li et. al, GCN 38027; Masi, GCN 38031; Moskvitin & Goranskij, GCN 38032; Yan et. al, GCN 38035; The TESS Mission, GCN 38050; Wang et. al, GCN 38055;) of a likely long GRB 241030A (The Fermi GBM team, GCN 37955; Klingler et. al, GCN 37956; SVOM/GRM team, GCN 37972; R. Pillera et. al, GCN 37979; Liang et. al, GCN 38026; Pal et. al, GCN 38074;) at the redshift of z ~ 1.411 (Zheng et. al, GCN 37959, Li et. al, GCN 38027) with 1.5-meter AZT-33IK telescope of Sayan (Mondy) observatory. Four observa! tions were carried out since 2024-10-31 until 2024-01-04. All observations were taken in the R-filter using the CMOS-photometer Andor Neo. We clearyl detect the optical afterglow on the 2024-10-31 epoch, and tentatively detect a possible host galaxy of GRB 241030A on other epochs. The preliminary photometry is given below: Date UTstart t-T0 Exp. Filter OT Err UL (mid, days) (n*s) (3sigma) 2024-10-31 11:25:44 1.253254 27*120 R 20.43 0.09 22.3 2024-11-02 11:50:32 3.272567 30*120 R 22.8 0.4 22.7 2024-11-03 11:59:10 4.278553 30*120 R 22.7 0.3 22.7 2024-11-04 11:40:01 5.264565 29*120 R 22.6 0.4 22.5 The magnitudes were calibrated against stars of the PanSTARSS-PS1 catalog. RA Dec R(Lupton transformations) 343.1048 +80.4430 17.287 343.2647 +80.4324 17.828 The reported magnitudes were not corrected for the Galactic extinction towards the GRB 241030A. From our observations we can suggest that photometry starting from 2024-11-02 could be the photometry of the host galaxy. View this GCN Circular online at https://gcn.nasa.gov/circulars/38105. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36072] GRB241105A: Fermi GBM Observation of a Short Burst with Extended Emission
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38104 SUBJECT: GRB241105A: Fermi GBM Observation of a Short Burst with Extended Emission DATE: 24/11/06 19:06:27 GMT FROM: sumanbala2210(a)gmail.com U. Pathak (IITB), O. Mukherjee (USRA), S. Rushikesh (IISER, TVM), S. Bala (USRA), O.J. Roberts (USRA/NASA-MSFC), E. Burns (LSU), P. Veres (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 16:06:04.66 UT on 05 November 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB241105A (trigger 752515569/241105671), which was also detected by Swift/BAT-GUANO (DeLaunay et al. 2024, GCN 38091), GOTO (Julakanti et al. 2024, GCN 38088), Swift-XRT (Kennea et al. 2024, GCN 38098), and SVOM/VT (Qiu et al. 2024, GCN 38099). The spectroscopic redshift of the optical counterpart observered by VLT/FORS2 (Izzo et al. 2024, GCN 38097) is 2.702. The Fermi GBM on-ground location is consistent with the Swift/BAT-GUANO position. The angle from the Fermi LAT boresight is 145 degrees. The GBM light curve consists of a short single pulse with a duration (T90) of about 1.4 s (50-300 keV) followed by significant extended emission for ~91 (50-300 keV) seconds. The extended emission appears to contain more fluence than the initial spike. The time-averaged spectrum from T0-0.5 to T0+2.6 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.2 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 702 +/- 278 keV. Considering the redshift of 2.702, and best fit model, we find the isotropic equivalent luminosity Liso = 7.5e+52 erg s-1 (1-10000 keV). The event fluence (10-1000 keV) in this time interval is (2.8 +/- 0.2)E-06 erg/cm^2. The 64-ms peak photon flux measured starting from T0-0.19 s in the 10-1000 keV band is 11 +/- 3 ph/s/cm^2. The total emission (short pulse + extended emission) from T0-2.6 to T0+97 s is best fit by a power law function with photon index -1.42 +/- 0.04. The total fluence (10-1000 keV) in this time interval is (1.1 +/- 0.1)E-05 erg/cm^2. Using z=2.702, we find Eiso = 1.5e+53 erg (1-10000 keV) when fitting the spectrum with a power law function with an exponential high-energy cutoff, with a power-law index of -0.03 +/- 0.4 and cutoff energy, parameterized as Epeak, of 221 +/- 30 keV. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/38104. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36071] Konus-Wind detection of GRB 241105A (short with extended emission)
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38103 SUBJECT: Konus-Wind detection of GRB 241105A (short with extended emission) DATE: 24/11/06 18:53:19 GMT FROM: Dmitry Frederiks at Ioffe Institute <fred(a)mail.ioffe.ru> D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The likely short GRB 241105A (Fermi GBM team, GCN 38085) triggered Konus-Wind (KW) at T0=57966.516 s UT (16:06:06.516). The burst light curve shows a short initial pulse, which starts at ~T0-0.5 s, peaks at ~T0, and has a total duration of ~1.5 s, which was followed by a weaker extended emission, visible in KW up to ~T0+60 s. The emission is seen up to ~4 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241105_T57966/ As observed by Konus-Wind, the burst had a fluence of (2.01 ± 0.47)x10^-5 erg/cm^2 and a 64-ms peak energy flux, measured from T0 - 0.064 s, of (2.37 ± 0.30)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+57.640 s) is best fit in the 20 keV - 15 MeV range by a GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.69 (-0.37,+0.67), the high energy photon index beta = -1.76 (-0.55,+0.21), the peak energy Ep = 374 (-165,+437) keV, chi2 = 98/97 dof. The spectrum of the initial pulse alone (measured from T0-0.512 s to T0+0.960 s) can be described by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.90(-0.15,+0.15) and Ep = 417(-82,+111) keV. Assuming the redshift z=2.702 (Izzo et al., GCN 38097) and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the burst isotropic energy release E_iso to (3.42 ± 0.80)x10^53 erg, the isotropic peak luminosity L_iso to (1.49 ± 0.18)x10^53 erg/s, the rest-frame peak energy of the time-integrated spectrum Ep,i,z to ~1380 keV, and the rest-frame peak energy at the peak of the emission Ep,p,z to ~1540 keV. With the obtained estimates, GRB 241105A fits 68% prediction bands for both 'Amati' and 'Yonetoku' relations derived for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021), see http://www.ioffe.ru/LEA/GRBs/GRB241105_T57966/GRB241105A_rest_frame.pdf All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/38103. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36070] LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38102 SUBJECT: LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search DATE: 24/11/06 17:26:38 GMT FROM: Erik Blaufuss at University of Maryland, College Park <blaufuss(a)umd.edu> IceCube Collaboration (http://icecube.wisc.edu/) reports: We have performed a search for track-like muon neutrino candidate events detected by IceCube consistent with the sky localization of the low-significance gravitational-wave candidate event S241106ba in a time range of 1000 seconds centered on the alert event time (2024-11-06 15:23:26 UTC to 2024-11-06 15:40:06 UTC) [1,2]. During this time period, IceCube was collecting good quality data. A single hypothesis test was conducted using a Bayesian approach to quantify the joint GW + neutrino event significance, which assumes a binary merger scenario and accounts for known astrophysical priors, such as GW source distance, in the statistical significance estimation [3]. One track-like event was found in spatial and temporal coincidence with the gravitational-wave candidate S241106ba calculated from the map circulated in the S241106ba-2-Preliminary notice. This represents an overall p-value of 0.0042 for the Bayesian search. The p-value measures the consistency of the observed track-like event with the known atmospheric backgrounds for this single map (not accounting for statistical trials from multiple GW events). Further details are available at https://gcn.nasa.gov/missions/icecube and at https://roc.icecube.wisc.edu/public/LvkNuTrackSearch. Properties of the coincident event are shown below: dt(s) RA(deg) Dec(deg) Angular uncertainty(deg) p-value(Bayesian) ------------------------------------------------------------------------------------- -137.94 210.20 20.74 1.84 0.0046 where: dt = Time of track event minus time of GW trigger (sec) Angular uncertainty = Angular uncertainty of track event: the radius of a circle representing 90% CL containment by area. p-value = the p-value for this specific track event from this search. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu [1] M. G. Aartsen et al 2020 ApJL 898 L10 [2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80 [3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017 View this GCN Circular online at https://gcn.nasa.gov/circulars/38102. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36069] LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38101 SUBJECT: LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search DATE: 24/11/06 17:25:51 GMT FROM: Erik Blaufuss at University of Maryland, College Park <blaufuss(a)umd.edu> IceCube Collaboration (http://icecube.wisc.edu/) reports: We have performed a search for track-like muon neutrino candidate events detected by IceCube consistent with the sky localization of the low-significance gravitational-wave candidate event S241102o in a time range of 1000 seconds centered on the alert event time (2024-11-02 03:08:31 UTC to 2024-11-02 03:25:11 UTC) [1,2]. During this time period, IceCube was collecting good quality data. A single hypothesis test was conducted using a Bayesian approach to quantify the joint GW + neutrino event significance, which assumes a binary merger scenario and accounts for known astrophysical priors, such as GW source distance, in the statistical significance estimation [3]. One track-like event was found in spatial and temporal coincidence with the gravitational-wave candidate S241102o calculated from the map circulated in the S241102o-2-Preliminary notice. This represents an overall p-value of 0.01 for the Bayesian search. The p-value measures the consistency of the observed track-like event with the known atmospheric backgrounds for this single map (not accounting for statistical trials from multiple GW events). Further details are available at https://gcn.nasa.gov/missions/icecube and at https://roc.icecube.wisc.edu/public/LvkNuTrackSearch. Properties of the coincident event are shown below: dt(s) RA(deg) Dec(deg) Angular uncertainty(deg) p-value(Bayesian) ------------------------------------------------------------------------------------- -44.62 338.77 42.96 1.48 0.010 where: dt = Time of track event minus time of GW trigger (sec) Angular uncertainty = Angular uncertainty of track event: the radius of a circle representing 90% CL containment by area. p-value = the p-value for this specific track event from this search. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu [1] M. G. Aartsen et al 2020 ApJL 898 L10 [2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80 [3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017 View this GCN Circular online at https://gcn.nasa.gov/circulars/38101. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36067] Konus-Wind detection of GRB 241021A
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38100 SUBJECT: Konus-Wind detection of GRB 241021A DATE: 24/11/06 13:13:48 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> V. Panteleeva, D. Frederiks, A. Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 241021A (IPN triangulation: Kozyrev et al., GCN 37847) triggered Konus-Wind at T0=53930.240 s UT (14:58:50.240). The burst light curve shows a multipeaked structure which starts at ~T0-25 s and has a total duration of ~236 s. The emission is seen up to ~16 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241021_T53930/ As observed by Konus-Wind, the burst had a fluence of 2.62(-0.21,+0.23)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+15.616 s, of 6.42(-1.49,+1.50)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+224 s) is best fit in the 20 keV - 16 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.09(-0.04,+0.04), the high energy photon index beta = -2.76(-0.60,+0.29), the peak energy Ep = 359(-25,+26) keV (chi2 = 103/97 dof). The spectrum near the maximum count rate (measured from T0+15.360 to T0+21.504 s) is best fit in the 20 keV - 16 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.05(-0.07,+0.07), the high energy photon index beta = -2.54(-0.58,+0.26), the peak energy Ep = 474(-60,+71) keV (chi2 = 102/97 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/38100. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36068] Konus-Wind detection of GRB 241021A
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38100 SUBJECT: Konus-Wind detection of GRB 241021A DATE: 24/11/06 13:13:48 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> V. Panteleeva, D. Frederiks, A. Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 241021A (IPN triangulation: Kozyrev et al., GCN 37847) triggered Konus-Wind at T0=53930.240 s UT (14:58:50.240). The burst light curve shows a multipeaked structure which starts at ~T0-25 s and has a total duration of ~236 s. The emission is seen up to ~16 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241021_T53930/ As observed by Konus-Wind, the burst had a fluence of 2.62(-0.21,+0.23)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+15.616 s, of 6.42(-1.49,+1.50)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+224 s) is best fit in the 20 keV - 16 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.09(-0.04,+0.04), the high energy photon index beta = -2.76(-0.60,+0.29), the peak energy Ep = 359(-25,+26) keV (chi2 = 103/97 dof). The spectrum near the maximum count rate (measured from T0+15.360 to T0+21.504 s) is best fit in the 20 keV - 16 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.05(-0.07,+0.07), the high energy photon index beta = -2.54(-0.58,+0.26), the peak energy Ep = 474(-60,+71) keV (chi2 = 102/97 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/38100. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36066] GRB 241105A: SVOM/VT optical afterglow observations
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38099 SUBJECT: GRB 241105A: SVOM/VT optical afterglow observations DATE: 24/11/06 12:23:57 GMT FROM: Liping Xin at NAOC, SVOM <xlp(a)nao.cas.cn> SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO), W. K. Zheng (UCB), Z. Q. Wang (GXU) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP),Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: VT started to observe the optical counterpart (Julakanti et al., GCN 38088; Izzo et al., GCN 38097) of GRB 241105A (Fermi GBM team, GCN 38085; DeLaunay et al., GCN 38091) in ToO mode from 2024-11-06T06:18:32 UT, about 14.2 hours after the burst. The VT conducted observations in VT_B band (400-650nm) and VT_R band (650-1000nm) simultaneously. The afterglow was clearly detected in both bands with the brightness of VT_B = 20.94 +/- 0.04 mag and VT_R = 19.92 +/- 0.03 mag in AB magnitude at the midtime of 14.36 hours after the burst. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/38099. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36065] GRB 241105A: Swift-XRT afterglow detection
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38098 SUBJECT: GRB 241105A: Swift-XRT afterglow detection DATE: 24/11/06 11:56:11 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.A. Kennea (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), M. A. Williams (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the BAT/GUANO localisation of the Fermi/GBM-detected burst GRB 241105A, collecting 3.9 ks of Photon Counting (PC) mode data between T0+38.3 ks and T0+62.2 ks. Two uncatalogued X-ray sources are detected consistent with being within 296 arcsec of the BAT/GUANO position, of which one ("Source 1") is fading with 2.2 sigma significance and thus is believed to be the GRB afterglow. Using 794 s of PC mode data and 2 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 66.24484, -49.75181 which is equivalent to: RA (J2000): 04h 24m 58.76s Dec(J2000): -49d 45' 06.5" with an uncertainty of 4.9 arcsec (radius, 90% confidence). This position is 18 arcsec from the BAT/GUANO position (DeLaunay et al., GCN Circ. 38091), and is consistent with the GOTO optical counterpart (Julakanti et al., GCN Circ. 38088). The light curve can be modelled with a power-law decay with a decay index of alpha=3.32 (+0.05, -2.26). If the light curve continues to decay with a power-law decay index of 3.32, the count rate at T+24 hours will be 1.8 x 10^-3 count s^-1 The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021728. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021728. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38098. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36064] GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.702
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38097 SUBJECT: GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.702 DATE: 24/11/06 09:31:01 GMT FROM: Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo(a)ucd.ie> L. Izzo (INAF-OACn & DARK/NBI), A. A. Chrimes (ESA/ESTEC & Radboud Univ.), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Saccardi (CEA/Irfu), A. Martin-Carrillo (UCD), A. J. Levan (Radboud Univ. and Warwick Univ.), B. P. Gompertz (Birmingham), N. R. Tanvir (U. Leicester), report on behalf of the Stargate collaboration: We observed the proposed optical counterpart (Julakanti et al., GCN 38088) of GRB 241105A (Fermi GBM team, GCN 38085; DeLaunay et al., GCN 38091). We used the FORS2 spectrograph mounted on the ESO VLT UT1 (Antu), equipped with grisms 300V (without order-sorting filter) and 300I (with filter OG590). The exposure time was 600 s per grism. Spectroscopy started on 2024 November 6.133 UT (about 11.08 hr after the trigger), and was carried out through moderately good seeing conditions (1"). In the acquisition image, we measure a preliminary magnitude R = 20.10 +/- 0.10 (Vega), calibrated using archival FORS2 zeropoints. From a preliminary reduction of the 300V spectrum, a continuum is detected over the wavelength range 4600 to 8700 AA. A trough due to Lya absorption is visible at the blue end. From the detection of multiple absorption features, which we interpret as due to C II, C IV, Si II, Si IV, Al II, Al III and Fe II, we infer a redshift of z = 2.702. We acknowledge the excellent support from the ESO staff in Paranal, in particular Maria Jose Rain and Israel Blanchard. View this GCN Circular online at https://gcn.nasa.gov/circulars/38097. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36063] GRB 241104A: Swift-XRT observations
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38096 SUBJECT: GRB 241104A: Swift-XRT observations DATE: 24/11/06 08:51:15 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> S. Dichiara (PSU), J.A. Kennea (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/GBM-detected burst GRB 241104A, using the localisation by SVOM/ECLAIRs (Schanne et al., GCN 38078), collecting 2.9 ks of Photon Counting (PC) mode data between T0+98.0 ks and T0+105.0 ks. No X-ray sources have been detected consistent with being within 256 arcsec of the SVOM/ECLAIRs position. The 3-sigma upper limit in the field is 0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.1e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). Three uncatalogued sources were detected too far from the GRB position to be likely afterglow candidates. These sources are also inconsistent with the X-ray localisation by EP/WXT (Zhou et al., GCN 38081). The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021727. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38096. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36062] GRB 241104A: Swift-XRT observations
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38096 SUBJECT: GRB 241104A: Swift-XRT observations DATE: 24/11/06 08:51:15 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> S. Dichiara (PSU), J.A. Kennea (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/GBM-detected burst GRB 241104A, using the localisation by SVOM/ECLAIRs (Schanne et al., GCN 38078), collecting 2.9 ks of Photon Counting (PC) mode data between T0+98.0 ks and T0+105.0 ks. No X-ray sources have been detected consistent with being within 256 arcsec of the SVOM/ECLAIRs position. The 3-sigma upper limit in the field is 0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.1e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). Three uncatalogued sources were detected too far from the GRB position to be likely afterglow candidates. These sources are also inconsistent with the X-ray localisation by EP/WXT (Zhou et al., GCN 38081). The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021727. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38096. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36061] GRB 240511A: LCO upper limits
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38095 SUBJECT: GRB 240511A: LCO upper limits DATE: 24/11/06 08:25:43 GMT FROM: ankur ghosh at ARIES <ghosh.ankur1994(a)gmail.com> Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Alexander Moskvitin, Yulia Sotnikova (SAO RAS) report on behalf of a larger collaboration. We observed the field of GRB 240511A (The Fermi GBM team, GCN 36428; Laha et al., GCN 36430; Evans, GCN 36431; Salvaggio et al., GCN 36443; Evans et al., GCN 36446; Krimm et al., GCN 36459) using the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at SAAO, South Africa. The telescope is equipped with a CCD (FOV: 13 x 13 arcmin, scale: 0.39 arcsec/pixel) and V, R filters. Observations began on May 12, starting 8.8269 hours after the GRB trigger. We did not detect the optical transient (OT) reported by Malesani and Milvang-Jensen (GCN 36442) and de Ugarte Postigo et al. (GCN 36498) in our images. Our non-detection upper limits are consistent with those reported by other teams (Lipunov et al., GCNs 36435, 36436; Niwano et al., GCN 36445; Mo et al., GCN 36452). UT Start–End Filter Exposure (s) Upper Limit 02:55:57–03:15:57 R 1200 R_lim = 21.8 09:39:59–10:04:59 V 1500 V_lim = 22.4 The field was calibrated against nearby SDSS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38095. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36060] GRB241104A: Fermi GBM Observation
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38094 SUBJECT: GRB241104A: Fermi GBM Observation DATE: 24/11/06 07:33:06 GMT FROM: Rushikesh Digambar Sonawane PHD231014 at IISER, TVM <rushikesh23(a)iisertvm.ac.in> S. Rushikesh (IISER, TVM), U. Pathak (IITB), O. Mukherjee (USRA), S. Bala (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 18:30:15.42 UT on 04 November 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB241104A (trigger 752437820/241104771) which was also detected by EP/WXT (Zhou et al. 2024, GCN 38081), SVOM/VT (Qiu et al. 2024, GCN 38086) and SVOM/ECLAIRs (Schanne et al. 2024, GCN 38078). The Fermi GBM on-ground location is consistent with the EP/WXT position. The angle from the Fermi LAT boresight is 62 degrees. The GBM light curve consist of single pulse with multiple peaks with a duration (T90) of about 10.5 s (50-300 keV). The time-averaged spectrum from T0-7.6 to T0+11.8 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.69 +/- 0.08 and the cutoff energy, parameterized as Epeak, is 74 +/- 2 keV. The event fluence (10-1000 keV) in this time interval is (3.4 +/- 0.8)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.6 s in the 10-1000 keV band is 6.9 +/- 0.3 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 68 +/- 3 keV, alpha = -0.6 +/- 0.1 and beta = -3.0 +/- 0.3. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/38094. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36059] GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38093 SUBJECT: GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source DATE: 24/11/06 05:57:04 GMT FROM: Liping Xin at NAOC, SVOM <xlp(a)nao.cas.cn> SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO). SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP),Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: After further analysis of all data acquired via the X-band downlink, the candidate was reported by VT commission team in the previous report(Qiu et al., GCN #38086), is a defect on the detector in VT_R band image,that is detectable in other fields, as well as in the new dark master images. A more detailed analysis is still in progress. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/38093. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36058] GRB 241105A: Swift ToO observations
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38092 SUBJECT: GRB 241105A: Swift ToO observations DATE: 24/11/06 02:44:22 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/GBM GRB 241105A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021728 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/GBM event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38092. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36057] GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
by GCN Circulars 06 Nov '24

06 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38091 SUBJECT: GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst DATE: 24/11/06 01:36:11 GMT FROM: Aaron Tohuvavohu at Caltech <aaron.tohu(a)gmail.com> James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 241105A onboard (T0: 2024-11-05T16:06:04 UTC, Fermi GCN 38085). The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The position of the burst is found via BAT imaging with SNR of 11. The position is: RA, Dec = 66.2381, -49.7547 deg which is RA(J2000) = 04h 24m 57.14s Dec(J2000) = -49d 45′ 16.9″ with an estimated uncertainty of 3 arcmin radius. This BAT-GUANO position is coincident with the optical transient discovered by GOTO (GCN 38088). XRT and UVOT follow-up has been triggered. Results of follow-up observations will be reported in future circulars. GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/38091. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36056] GRB 241104A: Swift ToO observations
by GCN Circulars 05 Nov '24

05 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38090 SUBJECT: GRB 241104A: Swift ToO observations DATE: 24/11/05 23:40:27 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/GBM GRB 241104A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021727 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/GBM event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38090. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36054] GRB 241104A: NOT optical non-detection
by GCN Circulars 05 Nov '24

05 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38089 SUBJECT: GRB 241104A: NOT optical non-detection DATE: 24/11/05 21:36:21 GMT FROM: Daniele B. Malesani at IMAPP / Radboud University <d.malesani(a)astro.ru.nl> D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Martin-Carrillo (UCD), D. Xu (NAOC), M. Turkki (NOT) report on behalf of a larger collaboration: We observed the candidate optical counterpart (Qiu et al., GCN 38086) of GRB 241104A (Fermi GBM team, GCN 38075; Schanne et al., GCN 38078; Zhang et al., GCN 38082), using the Nordic Optical Telescope (NOT) equipped with the ALFOSC imager. Observations were carried out in the SDSS r, i, and z filters. No object is detected at the location of the candidate counterpart, down to the following 3-sigma limiting magnitudes: r > 24.0 AB 2024 Nov 5.859 UT (1.088 days after the trigger) i > 23.7 AB 2024 Nov 5.871 UT (1.100 days after the trigger) z > 22.2 AB 2024 Nov 5.847 UT (1.077 days after the trigger) Calibration was performed against nearby Pan-STARRS sources. View this GCN Circular online at https://gcn.nasa.gov/circulars/38089. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36055] GRB 241104A: NOT optical non-detection
by GCN Circulars 05 Nov '24

05 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38089 SUBJECT: GRB 241104A: NOT optical non-detection DATE: 24/11/05 21:36:21 GMT FROM: Daniele B. Malesani at IMAPP / Radboud University <d.malesani(a)astro.ru.nl> D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Martin-Carrillo (UCD), D. Xu (NAOC), M. Turkki (NOT) report on behalf of a larger collaboration: We observed the candidate optical counterpart (Qiu et al., GCN 38086) of GRB 241104A (Fermi GBM team, GCN 38075; Schanne et al., GCN 38078; Zhang et al., GCN 38082), using the Nordic Optical Telescope (NOT) equipped with the ALFOSC imager. Observations were carried out in the SDSS r, i, and z filters. No object is detected at the location of the candidate counterpart, down to the following 3-sigma limiting magnitudes: r > 24.0 AB 2024 Nov 5.859 UT (1.088 days after the trigger) i > 23.7 AB 2024 Nov 5.871 UT (1.100 days after the trigger) z > 22.2 AB 2024 Nov 5.847 UT (1.077 days after the trigger) Calibration was performed against nearby Pan-STARRS sources. View this GCN Circular online at https://gcn.nasa.gov/circulars/38089. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36053] GRB 241105A: GOTO tentative optical counterpart candidate
by GCN Circulars 05 Nov '24

05 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38088 SUBJECT: GRB 241105A: GOTO tentative optical counterpart candidate DATE: 24/11/05 20:17:55 GMT FROM: Yashaswi Julakanti at University of Leicester <skyj1(a)leicester.ac.uk> Y. Julakanti, G. Ramsay, B. P. Gompertz, K. Ackley, D. O'Neill, A. Kumar, R. Starling, M. J. Dyer, J. Lyman, K. Ulaczyk, F. Jimenez-Ibarra, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle and D. Pollacco report on behalf of the GOTO collaboration: We report on optical observations with the Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022; Dyer et al. 2024) in response to the GRB 241105A (Fermi GBM Team, GCN 38085). Targeted imaging covered the Fermi localisation region from 2024-11-05 16:19:10 UT, (+0.22h post trigger) to 2024-11-05 17:42:50 UT (+1.61h post trigger). In total, 277.9 square degrees within the 90% contour were imaged, resulting in a coverage total of ~84.3% of the total 2D localisation probability. The observations consisted of 4x90s exposures in the GOTO L-band (400-700 nm). In total, 101 images were taken, across 10 unique pointings, with an average 5-sigma depth of 20.4 mag. Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using deeper template observations. Source candidates were initially filtered using a classifier (Killestein et al. 2021) and cross-matched against a variety of contextual and minor planet catalogs. Human vetting was carried out in real time on any candidates that passed the above checks. A new optical source GOTO24ibf is identified within the GBM 90% localisation region. We find no evidence of the source down to 20.0 mag prior to the GRB trigger time in previous GOTO observations taken at 2024-11-05 10:48:54 UTC (t-t0 = -5.29h) or the ATLAS forced photometry server (Shingles et al. 2021). There is a faint ambiguous underlying source at the position of GOTO24ibf visible in DESI legacy survey images that we cannot definitively identify as a star or galaxy. Due to the onset of twilight at Siding Spring Observatory, only a single epoch of observations were obtained, preventing any assessment of the evolution of the source. We encourage further deeper follow-up observations. +-------------------------------------------------------------------------------------------------------+ | Internal name | Time (UT) | t-t0 (h) | RA (J2000) | Dec (J2000) | Mag | +-------------------------------------------------------------------------------------------------------+ | GOTO24ibf | 2024-11-05 16:34:35 | 0.48 | 04:24:59.0 | -49:45:09.3 | 17.21 +/- 0.01 | Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction. GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC). View this GCN Circular online at https://gcn.nasa.gov/circulars/38088. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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