January 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37057] Fermi-LAT Gamma-ray Observations of IceCube-250101A
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39048 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-250101A DATE: 25/01/27 17:49:14 GMT FROM: chiara.bartolini-1(a)unitn.it C. Bartolini (Università di Trento & INFN Bari), S. Garrappa (Weizmann Institute of Science), L. Pfeiffer (Univ. of Wuerzburg), S. Buson (DESY, Univ. of Wuerzburg) and J. Sinapius (DESY) and P. M. Veres (Ruhr University Bochum) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC250101A neutrino event (GCN 38770) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2025-01-01 21:13:17.730 UTC (T0) with J2000 position RA = 318.96 (+0.64, -0.63) deg, Decl. = -0.93 (+0.49, -0.44) deg 90% PSF containment. One cataloged >100 MeV gamma-ray source is located within the 90% IC-250101A localization error, at a distance of roughly 0.3 deg (Fourth Fermi-LAT catalog, 4FGL-DR4, The Fermi-LAT collaboration 2023, arXiv:2307.12546). This is the object 4FGL J2115.9-0113. Based on a preliminary analysis of the LAT data over the timescale of one month prior T0, this object is not significantly detected at gamma-rays. We searched for the existence of intermediate (days to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (>5sigma) new excess emission (> 100 MeV) within the IC250101A 90% confidence localization. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IceCube best-fit position, the >100 MeV flux upper limit (95% confidence) is <2.0e-09 ph cm^-2 s^-1 for ~16-years (2008-08-04 / T0), <1.1e-09 ph cm^-2 s^-1 for a 1-month integration time before T0. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this source will continue. For this source, the Fermi-LAT contact person is C. Bartolini (chiara.bartolini at ba.infn.it). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. View this GCN Circular online at https://gcn.nasa.gov/circulars/39048. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37056] GRB 250127A: SVOM/VT upper limit
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39047 SUBJECT: GRB 250127A: SVOM/VT upper limit DATE: 25/01/27 16:08:37 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> SVOM/VT team: L.P. Xin, Y. L. Qiu, H.L. Li., C. Wu, D.H. Zhao, Z.H. Yao, Y.N. Ma, X.H. Han, J. Wang, W.J.Xie, H.B. Cai，J.Y. Wei（NAOC）， J. Palmerio (CEA) and S. Vergani (obs.Paris) report on behalf of the SVOM team: GRB 250127A (Wu et al., GCN 39041) was observed by SVOM/VT after the automatic slew of the platform. The VT conducted observations in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously. With the VHF and X band downlinked data, no any credible candidates were found in our single or stacked images within either the errorbox of Eclairs (Wu et al., GCN 39041), or the errorbox of source #2 detected by Swift/XRT (Swift Team,GCN 39044). The 3 sigma limits in AB magnitude were derived as follows: --------------------------------------------------------- (t-T0)_mid(min) exptime(s) Band upperlim(3sigma) 2.5 15 VT_B 20.6 2.5 15 VT_R 20.3 78.08 23*100 VT_B 23.6 79.75 23*100 VT_R 23.4 147.38 48*100+15 VT_B 23.9 147.01 46*100+2*15 VT_R 23.7 This is consistent with the non-detection report (Turpin et al., GCN 39043). 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/39047. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37055] GRB 250127B: Fermi GBM Final Real-time Localization
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39046 SUBJECT: GRB 250127B: Fermi GBM Final Real-time Localization DATE: 25/01/27 15:25:16 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 15:14:38 UT on 27 Jan 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250127B (trigger 759683683.583014 / 250127635). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 126.4, Dec = -14.0 (J2000 degrees, equivalent to J2000 08h 25m, -14d 00'), with a statistical uncertainty of 4.8 degrees. The angle from the Fermi LAT boresight is 96.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250127635/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250127635/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250127635/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39046. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37054] IPN triangulation of GRB 250119C
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39045 SUBJECT: IPN triangulation of GRB 250119C DATE: 25/01/27 12:48:35 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind 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, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The long-duration GRB 250119C (Fermi-GBM detection: The Fermi GBM team, GCN 38990; Smith and Meegan, GCN 39030; Swift-BAT/GUANO detection: Ronchini et al., GCN 39008) was detected by Fermi (GBM trigger 759019271), Swift (BAT), Konus-Wind, and INTEGRAL (SPI-ACS) at about 81666 s UT (22:41:06). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 158.335 (10h 33m 20s) +20.621 (+20d 37' 17") Corners: 135.211 (09h 00m 51s) +18.215 (+18d 12' 54") 179.680 (11h 58m 43s) +14.804 (+14d 48' 15") 182.465 (12h 09m 52s) +23.952 (+23d 57' 06") 135.484 (09h 01m 56s) +27.480 (+27d 28' 47") --------------------------------------------- The error box area is 393.4 sq. deg, and its maximum dimension is 44.2 deg (the minimum one is 9.2 deg). The Sun distance was 124 deg. This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM (GCN 38990) and Swift-BAT/GUANO (GCN 39008) localizations. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250119_T81666/IPN The HEALPix triangulation map is the multi-order HEALPix in units of probability density. View this GCN Circular online at https://gcn.nasa.gov/circulars/39045. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37053] GRB 250127A: Swift ToO observations
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39044 SUBJECT: GRB 250127A: Swift ToO observations DATE: 25/01/27 10:13:24 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 250127A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021757 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/39044. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37052] GRB 250127A: LCO optical upper limit
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39043 SUBJECT: GRB 250127A: LCO optical upper limit DATE: 25/01/27 09:58:37 GMT FROM: Damien Turpin at CEA-Saclay <dturpin-astro(a)hotmail.com> D. Turpin, J. T. Palmerio, A. Saccardi (CEA), B. Schneider (LAM), S. Basa (UAR Pytheas, OHP, LAM), S. Vergani (GEPI/Obs. de Paris), E. Le Floc'h (CEA), C. Wu, L.-P Xin (NAOC) on behalf of a larger collaboration. We observed the field of GRB 250127A detected by SVOM (Wu et al., GCN 39041) with the Sinistro instrument mounted on the 1-m telescope of the LCO network and the SCICAM QHY600 camera mounted on the 40 cm telescope, located at the Cerro Tololo, Chile. Our observation started at 2025-01-27T07:12:38.385 UTC (2.13 hr after the trigger) with a series of 2 x180s images using the PS1-z filter and 4 x 180s exposure using the sdss-r filter. We did not detect any uncatalogued optical source inside the SVOM/ECLAIRs error region. We derived the preliminary following upper limit z > 17.8 (T-TGRB = 2.23h ,midtime) and r > 22.1 (T-TGRB = 2.32h ,midtime) given at 5 sigma (AB system) calibrated with the PanSTARRS DR2 catalog and not corrected for galactic extinction. At the time of our observations, we note the presence of the minor planet designated as 2007 RT45 at RA, DEC (J2000): 11:18:42.1, +03:21:34 just outside the SVOM/ECLAIRs localisation error region. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101004719. View this GCN Circular online at https://gcn.nasa.gov/circulars/39043. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37051] GRB 241223A: cubesat Avion detection
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39042 SUBJECT: GRB 241223A: cubesat Avion detection DATE: 25/01/27 08:52:00 GMT FROM: Andrey Bogomolov at Moscow State University <aabboogg(a)srd.sinp.msu.ru> A. Bogomolov, V. Bogomolov, A. Iyudin, S. Svertilov, N. Vasiliev on behalf of the MSU “Sozvezdie-270” team, report: At 2024-12-23 ~12:08:45 UT the long-duration GRB 241223A (Fermi GBM detection: GCN #38650; GRBAlpha detection: GCN #38678) was detected by the DeCoR-1 and DeCoR-3 instruments on the cubesat Avion of the Moscow University project “Constellation-270” [1]. Total amount of photons detected by Avion is 620 (DeCoR-1, energy band 40-500 keV) and ~1540 (DeCoR-3, >30 keV), it corresponds to a fluence of ~7*10^(-6) erg/cm^2 in the range 30-500 keV. LC in the energy range of 30-500 keV has two main episodes with a maximum flux of ~1.6 phot/(cm^2*s) in the 1st peak with a duration of ~11 s, and ~11.7 phot/(cm^2*s) in the 2nd peak with a duration of ~12 s. А total duration (T90) of the burst is ~31 s. The light curve obtained by Avion is available here: https://swx.sinp.msu.ru/models/grb_cat/data/pictures/GRB20241223A_Acion_Dec… Parameters of GRB 241223A as well as 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 Moscow University 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/39042. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37050] GRB 250127A: SVOM detection of a long burst
by GCN Circulars 27 Jan '25

27 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39041 SUBJECT: GRB 250127A: SVOM detection of a long burst DATE: 25/01/27 06:17:14 GMT FROM: Stéphane Schanne at CEA Paris-Saclay/IRFU <s.schanne(a)cea.fr> C. Wu, D.-H. Zhao, W.-J. Xie (NAOC), S. Schanne (CEA), C.-W. Wang (IHEP), D. Götz (CEA) report on behalf of the SVOM team: The SVOM/ECLAIRs telescope triggered and located the long duration GRB 250127A (sb25012701) starting at 2025-01-27T05:04:46 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 both the on-board Count-Rate Trigger (CRT) and Image Trigger (IMT) and 12 alerts were received. The best detection is obtained by IMT with a signal-to-noise ratio of 17.45 in the 8-120 keV energy band over a time window of 40.96 s starting at Tb. In the real-time light-curve the burst is well seen in the 5-50 keV band and not above. The localization of the best Alert is RA, Dec = 169.589, 3.346 (J2000). The uncertainty on this position is 4.8 arcminutes at 90% C.L. which includes 2 arcminutes of systematic uncertainty in quadrature. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250127A.png SVOM performed an automatic slew on this burst, MXT and VT results will be reported later. 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. The SVOM point of contact for this burst is: Donghua Zhao ( zhaodh(a)bao.ac.cn ) View this GCN Circular online at https://gcn.nasa.gov/circulars/39041. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37049] GRB 250126A: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 26 Jan '25

26 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39040 SUBJECT: GRB 250126A: CALET Gamma-Ray Burst Monitor detection DATE: 25/01/26 15:05:47 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> S. Sugita, A. Yoshida, T. Sakamoto, Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (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 250126A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 39035; BALROG localization: Preis et al., GCN Circ 39036; MAXI/GSC detection: Okada et al., GCN Circ 39038) was detected in the ground analysis of the CALET Gamma-ray Burst Monitor (CGBM) data around 04:58:50.99 on 26 January 2025 (referenced to the Fermi-GBM Observation: GCN Circ. 39035). (https://cgbm.calet.jp/cgbm_trigger/flight/1421902612/index.html) The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure that starts at T-0.3 sec, peaks at T+85.4 sec, and ends at T+100.1 sec. The T90 and T50 durations measured by the HXM2 data are 96.9 +/- 1.4 sec and 82.5 +/- 1.3 sec (7-100 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1421902612/ 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/39040. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37048] EP250125A: Non-detection from Fermi-GBM Observations
by GCN Circulars 26 Jan '25

26 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39039 SUBJECT: EP250125A: Non-detection from Fermi-GBM Observations DATE: 25/01/26 14:36:25 GMT FROM: mariaedvige.ravasio(a)ru.nl M. E. Ravasio (Radboud Univ.), E. Burns (LSU), and P.G. Jonker (Radboud Univ.) report on behalf of the Fermi-GBM Team: The location of the EP-WXT event EP250125A (Wu et al., GCN 39028) was occulted by the Earth for Fermi at the EP trigger time T0=2025-01-25T02:37:31 UTC, as well as at the starting time 2025-01-25T02:36:19 UTC (T0-72 s) of the event reported by Wu et al. (GCN 39028). There was no Fermi-GBM onboard trigger around EP-WXT times. The location becomes visible at around ~T0+174 s. The GBM targeted search [1], the most sensitive, coherent search for GRB-like signals, was run in the time interval [-50;+500] s from the EP starting time (T0-72 s), seeking signals between 64 ms and 32.768 s in duration. No signal consistent both temporally and spatially is identified, as confirmed by visual inspection of the data. [1] Goldstein et al. 2019 arXiv:1903.12597 View this GCN Circular online at https://gcn.nasa.gov/circulars/39039. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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