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[vsnet-grb-info 36443] GRB 241206A: Fermi GBM Final Real-time Localization
by GCN Circulars 06 Dec '24

06 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38447 SUBJECT: GRB 241206A: Fermi GBM Final Real-time Localization DATE: 24/12/06 12:17:08 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 12:06:49 UT on 6 Dec 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241206A (trigger 755179614.876062 / 241206505). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 215.5, Dec = 56.0 (J2000 degrees, equivalent to J2000 14h 22m, 56d 00'), with a statistical uncertainty of 5.2 degrees. The angle from the Fermi LAT boresight is 38.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241206505/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241206505/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241206505/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38447. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36442] EP241201a: 1.6m Mephisto Optical Upper Limits
by GCN Circulars 06 Dec '24

06 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38446 SUBJECT: EP241201a: 1.6m Mephisto Optical Upper Limits DATE: 24/12/06 02:27:12 GMT FROM: Brajesh Kumar at SWIFAR, YNU <brajesh(a)ynu.edu.cn> Guowang Du, Jinghua Zhang, Shiyan Zhong, Yiheng Xie, Yanan Cao, Yu Pan, Xingzhu Zou, Xinlei Chen, Brajesh Kumar, Yuanpei Yang, Yuan Fang, Xiangkun Liu, Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team: The field of EP241201a (Chen et al., GCN 38415) was observed with the 1.6m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University located at Lijiang Observatory starting from 11:21:59 UT 2024-12-04 (~2.5 days after the trigger). Several frames with exposures of 300s and 294s in the uvgr and iz bands were taken. In the stacked images, no credible candidate was detected within the EP-WXT error circle (Chen et al., GCN 38415) and at the location of possible source (Lee et al., GCN 38418). This is consistent with the reports by Liu et al. (GCN 38425), and Perez-Garcia et al. (GCN 38427). The 3-sigma upper limits are listed below. Start_Time(UT) Band Exp(s) Lim-mag(AB) 2024-12-04T11:22:00 u 300*3 >21.93 2024-12-04T11:38:30 v 300*3 >22.34 2024-12-04T11:21:59 g 300*3 >22.29 2024-12-04T11:38:30 r 300*3 >22.59 2024-12-04T11:22:00 i 294*3 >21.23 2024-12-04T11:38:31 z 294*2 >20.18 -------------------------------------------------------------------------- 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/38446. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36441] GRB 241204A: COLIBRÍ Optical Upper Limit
by GCN Circulars 05 Dec '24

05 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38445 SUBJECT: GRB 241204A: COLIBRÍ Optical Upper Limit DATE: 24/12/05 21:16:51 GMT FROM: Dornic Damien <dornicdamien(a)gmail.com> Francesco Magnani (CPPM), J.-G. Ducoin (CPPM), Damien Dornic (CPPM), Alan M. Watson (UNAM), Margarita Pereyra (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), S. Antier (OCA), Jean-Luc Atteia (IRAP), Nathaniel R. Butler (ASU), Francis Fortin (IRAP), Simona Lombardo (LAM), and report: We imaged the field of GRB 241204A detected by Fermi/LAT (Bissaldi et al., GCN 38436) and Fermi/GBM (Godwin et al., GCN 38441) during the commissioning of the COLIBRÍ (SVOM/F-GFT) telescope at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico. The observations started 23.9 hours after the GRB trigger. We obtained 1200 seconds of exposure with the engineering test camera in a red filter that approximates SDSS r. The observation covers 13 arcmin field of view centered to the LAT coordinates. The data were reduced using custom software and then analysed and calibrated against the PS1 catalog using the STDWeb service (Karpov et al. 2022). We estimate an upper limit of 20.6 mag (10 sigma). This limiting magnitude is consistent with other optical observations of MASTER (Lipunov et al., GCN Circ. 38440) and DDOTI (Becerra et al., GCN Circ. 38442). We warmly thank the COLIBRI engineering team and the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/38445. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36440] EP241202b: KAIT optical upper limit
by GCN Circulars 05 Dec '24

05 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38444 SUBJECT: EP241202b: KAIT optical upper limit DATE: 24/12/05 20:05:09 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 EP241202b (Zhou et al., GCN 38426) starting at ~14.3h after the trigger and again at ~39.0h after the trigger. A set of 30x60s images were obtained in the clear (roughly R) filters for each run. We do not detect the optical counterpart candidate reported by Ngeow et al. (GCN 38433) in our coadd images with upper limits of 21.5 mag for both runs. View this GCN Circular online at https://gcn.nasa.gov/circulars/38444. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36439] LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
by GCN Circulars 05 Dec '24

05 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38443 SUBJECT: LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes DATE: 24/12/05 15:33:48 GMT FROM: David Paneque at Max Planck Institute for Physics <dpaneque(a)mppmu.mpg.de> D. Paneque (MPP Munich), M. Teshima (MPP Munich), M. Seglar Arroyo (IFAE Barcelona), D. Miceli (INFN Padova), A. Stamerra (INAF Rome), J. Jimenez (IFAE Barcelona), S. Menon (University & INAF Rome), A. Simongini (University & INAF Rome) on behalf of the LST and MAGIC Collaborations report: We observed the Swift/BAT-GUANO gamma-ray counterpart candidate (GRB 241125A, DeLaunay, GCNC 38308) presumably related to the GW S241125n (LVK Collaboration, GCNC 38305, 38315). A total of 4h of pointed observations towards the gamma-ray counterpart candidate position were obtained, starting approximately on Nov 25, 20 UT (i.e. about 19h post trigger time). A preliminary offline analysis of the LST-1 and MAGIC dataset shows no excess of gamma-rays above 300 GeV at the position of the Swift/BAT-GUANO candidate. These results have been obtained using the LST analysis software, lstchain (https://zenodo.org/records/14227973 , v0.10.13), and the MAGIC analysis software MARS (Zanin et al. 2013). Observations were affected by the presence of clouds and by reduced atmospheric transparency. A more in-depth analysis of this data set is ongoing. LST-1 is the first telescope of the Large-Sized Telescope (LST) for the Cherenkov Telescope Array Observatory. It is located on the Canary island of La Palma, Spain. The telescope design is optimized for observing gamma rays in the range from 20 GeV to 3 TeV. The LST-1 contact persons for these observations are Masahiro Teshima (mteshima(a)mpp.mpg.de) and Monica Seglar-Arroyo (mseglar(a)ifae.es). The preliminary offline analysis has been performed by Sweta Menon (sweta.menon(a)inaf.it) and Juan Jimenez (juan.jimenez(a)ifae.es). MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located on the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 50 TeV. The MAGIC contact persons for these observations are David Paneque (dpaneque(a)mpp.mpg.de), Antonio Stamerra (antonio.stamerra(a)inaf.it) and Davide Miceli (davide.miceli(a)pd.infn.it). The preliminary offline analysis has been performed by Andrea Simongini (andrea.simongini(a)inaf.it). View this GCN Circular online at https://gcn.nasa.gov/circulars/38443. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36438] GRB 241204A: DDOTI Upper Limits on the Afterglow
by GCN Circulars 05 Dec '24

05 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38442 SUBJECT: GRB 241204A: DDOTI Upper Limits on the Afterglow DATE: 24/12/05 11:40:03 GMT FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra(a)roma2.infn.it> Rosa L. Becerra (Tor Vergata, Roma), Alan M. Watson (UNAM), Eleonora Troja (Tor Vergata, Roma), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM), and Margarita Pereyra (UNAM) report: We observed the field of the GRB 241204A detected by Fermi/LAT (Bissaldi et al., GCN [38436](https://gcn.nasa.gov/circulars/38436)) and Fermi/GBM (Godwin et al., GCN 38441) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir (http://ddoti.astroscu.unam.mx) on 2024-12-05 from 02:29 to 03:54 UTC (22.83 to 24.25 hrs after the event), obtaining a total of 48 minutes of exposure in the w filter down to a 10-sigma limiting magnitude of w = 20.6. Comparing our observations to the USNO-B1 and PanSTARRS PS1 DR2 catalogues, we detect no uncatalogued sources within the observed field to our 10-sigma limit within the error radius reported by Fermi/LAT (Bissaldi et al., GCN 38436). We thank the DDOTI technical team and the staff of the Observatorio Astronómico Nacional. View this GCN Circular online at https://gcn.nasa.gov/circulars/38442. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36437] GRB 241204A: Fermi GBM Observation
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38441 SUBJECT: GRB 241204A: Fermi GBM Observation DATE: 24/12/04 21:07:30 GMT FROM: Matt Godwin <msg0028(a)uah.edu> Matt Godwin (UAH), E. Bissaldi (Politecnico and INFN Bari), and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 03:39:22.51 UT on 04 December 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241204A (trigger 754976367/241204152). which was also detected by Fermi-LAT (E. Bissaldi et al. 2024, GCN 38436). The Fermi GBM on-ground location is consistent with the Fermi-LAT position. The angle from the Fermi LAT boresight is 26 degrees. The GBM light curve consists of two peaks with a duration (T90) of about 0.8 s (50-300 keV). The time-averaged spectrum from T0-0.4 to T0+1.0 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.31 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 3453 +/- 1070 keV. The event fluence (10-1000 keV) in this time interval is (2.22 +/- 0.09)E-06 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0.64 s in the 10-1000 keV band is 41 +/- 2 ph/s/cm^2. 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/38441. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36436] Fermi GRB 241204A: Global MASTER-Net observations report
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38440 SUBJECT: Fermi GRB 241204A: Global MASTER-Net observations report DATE: 24/12/04 16:30:42 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 241204A ( E. Bissaldi et al., GCN 38436) errorbox 39000 sec after notice time and 40326 sec after trigger time at 2024-12-04 14:51:28 UT, with upper limit up to 19.8 mag. Observations started at twilight. The observations began at zenith distance = 41 deg. The sun altitude is -13.4 deg. The galactic latitude b = -26 deg., longitude l = 53 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2695247 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 40356 | 2024-12-04 14:51:28 | MASTER-Kislovodsk | (21h 05m 11.61s , +06d 39m 14.6s) | C | 60 | 17.3 | 40617 | 2024-12-04 14:55:49 | MASTER-Kislovodsk | (21h 05m 10.85s , +06d 36m 35.4s) | C | 60 | 17.7 | 40677 | 2024-12-04 14:55:49 | MASTER-Kislovodsk | (21h 05m 10.85s , +06d 36m 35.3s) | C | 180 | 18.4 | Coadd 41157 | 2024-12-04 14:55:49 | MASTER-Kislovodsk | (21h 05m 10.84s , +06d 36m 35.4s) | C | 1140 | 19.8 | Coadd 40697 | 2024-12-04 14:57:09 | MASTER-Kislovodsk | (21h 05m 17.71s , +06d 36m 52.8s) | C | 60 | 17.8 | 40776 | 2024-12-04 14:58:28 | MASTER-Kislovodsk | (21h 05m 13.79s , +06d 38m 06.3s) | C | 60 | 17.7 | 40856 | 2024-12-04 14:59:48 | MASTER-Kislovodsk | (21h 05m 14.85s , +06d 36m 37.2s) | C | 60 | 17.8 | 40976 | 2024-12-04 14:59:48 | MASTER-Kislovodsk | (21h 05m 14.85s , +06d 36m 37.1s) | C | 300 | 19.0 | Coadd 40966 | 2024-12-04 15:01:08 | MASTER-Kislovodsk | (21h 05m 17.13s , +06d 38m 07.3s) | C | 120 | 18.4 | 41105 | 2024-12-04 15:03:27 | MASTER-Kislovodsk | (21h 05m 12.10s , +06d 37m 15.1s) | C | 120 | 18.5 | 41245 | 2024-12-04 15:05:47 | MASTER-Kislovodsk | (21h 05m 11.16s , +06d 38m 11.1s) | C | 120 | 18.4 | 41365 | 2024-12-04 15:05:47 | MASTER-Kislovodsk | (21h 05m 11.16s , +06d 38m 11.1s) | C | 360 | 19.2 | Coadd 41385 | 2024-12-04 15:08:07 | MASTER-Kislovodsk | (21h 05m 18.09s , +06d 37m 07.3s) | C | 120 | 18.5 | 41525 | 2024-12-04 15:10:27 | MASTER-Kislovodsk | (21h 05m 11.35s , +06d 36m 04.7s) | C | 120 | 18.5 | 41665 | 2024-12-04 15:12:47 | MASTER-Kislovodsk | (21h 05m 18.32s , +06d 36m 12.3s) | C | 120 | 18.6 | 41725 | 2024-12-04 15:12:47 | MASTER-Kislovodsk | (21h 05m 18.32s , +06d 36m 12.3s) | C | 240 | 19.0 | Coadd 41774 | 2024-12-04 15:15:06 | MASTER-Kislovodsk | (21h 05m 14.44s , +06d 37m 37.2s) | C | 60 | 18.0 | 41854 | 2024-12-04 15:16:26 | MASTER-Kislovodsk | (21h 05m 15.52s , +06d 36m 04.1s) | C | 60 | 18.0 | 41934 | 2024-12-04 15:17:46 | MASTER-Kislovodsk | (21h 05m 18.53s , +06d 37m 41.4s) | C | 60 | 18.0 | 42114 | 2024-12-04 15:17:46 | MASTER-Kislovodsk | (21h 05m 18.51s , +06d 37m 41.2s) | C | 420 | 19.5 | Coadd 42073 | 2024-12-04 15:19:05 | MASTER-Kislovodsk | (21h 05m 12.75s , +06d 36m 52.9s) | C | 180 | 18.8 | 42273 | 2024-12-04 15:22:25 | MASTER-Kislovodsk | (21h 05m 11.88s , +06d 37m 48.3s) | C | 180 | 18.8 | 42473 | 2024-12-04 15:25:45 | MASTER-Kislovodsk | (21h 05m 18.89s , +06d 36m 44.0s) | C | 180 | 18.8 | 43655 | 2024-12-04 15:46:27 | MASTER-Kislovodsk | (20h 46m 30.15s , +05d 04m 06.4s) | C | 60 | 17.7 | 44775 | 2024-12-04 16:05:07 | MASTER-Kislovodsk | (20h 54m 32.68s , +05d 03m 31.1s) | C | 60 | 17.5 | 44855 | 2024-12-04 16:06:27 | MASTER-Kislovodsk | (20h 46m 28.95s , +05d 04m 25.4s) | C | 60 | 17.8 | 44935 | 2024-12-04 16:07:47 | MASTER-Kislovodsk | (20h 54m 29.51s , +05d 02m 58.9s) | C | 60 | 17.7 | 45014 | 2024-12-04 16:09:06 | MASTER-Kislovodsk | (20h 46m 31.91s , +05d 04m 23.6s) | C | 60 | 17.8 | 45154 | 2024-12-04 16:10:26 | MASTER-Kislovodsk | (20h 58m 42.92s , +03d 10m 49.9s) | C | 180 | 18.2 | 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/38440. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36435] GRB 241130A: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38439 SUBJECT: GRB 241130A: CALET Gamma-Ray Burst Monitor detection DATE: 24/12/04 13:47:11 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> S. Ricciarini (U of Florence), 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, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 241130A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 38405; Fermi GBM Detection: Sharma et al., GCN Circ. 38421; EIRSAT-1 GMOD Detection: McDermott et al., GCN Circ. 38423; IPN triangulation: Ridnaia et al., GCN Circ. 38424; Konus-Wind detection: Frederiks et al., GCN Circ. 38429) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 23:13:45.911 UTC on 30 November 2024 (https://cgbm.calet.jp/cgbm_trigger/flight/1417043611/index.html). The burst signal was seen by all CGBM detectors. 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 single pulse that starts at T-0.4 sec, peaks at T+0.1 sec, and ends at T+5.9 sec. The T90 and T50 durations measured by the SGM data are 5.4 +/- 0.8 sec and 2.4 +/- 0.5 sec (40-1000 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1417043611 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/38439. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36434] GRB 241130A: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38439 SUBJECT: GRB 241130A: CALET Gamma-Ray Burst Monitor detection DATE: 24/12/04 13:47:11 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> S. Ricciarini (U of Florence), 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, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 241130A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 38405; Fermi GBM Detection: Sharma et al., GCN Circ. 38421; EIRSAT-1 GMOD Detection: McDermott et al., GCN Circ. 38423; IPN triangulation: Ridnaia et al., GCN Circ. 38424; Konus-Wind detection: Frederiks et al., GCN Circ. 38429) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 23:13:45.911 UTC on 30 November 2024 (https://cgbm.calet.jp/cgbm_trigger/flight/1417043611/index.html). The burst signal was seen by all CGBM detectors. 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 single pulse that starts at T-0.4 sec, peaks at T+0.1 sec, and ends at T+5.9 sec. The T90 and T50 durations measured by the SGM data are 5.4 +/- 0.8 sec and 2.4 +/- 0.5 sec (40-1000 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1417043611 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/38439. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36433] GRB 241128A : RAPAS follow-up observations
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38438 SUBJECT: GRB 241128A : RAPAS follow-up observations DATE: 24/12/04 11:08:56 GMT FROM: Thierry Midavaine at GRANDMA <thierrymidavaine(a)sfr.fr> Thierry Midavaine on behalf of the RAPAS network reports (#3) : Cédric Latgé, Patrick Martinez [1], Pierre-Michel Bergé, Erik Guthleben, Patrick Martinez [2], Thierry Midavaine [3] observed the Gamma-Ray Burst GRB241128A (R. Brivio et al. GCN 38367, K.L. Page GCN 38368) using [1][2] ADAGIO N 820mm telescope f=3.1m at Belesta Observatory (IAU A05) equiped with a Moravian C3 CMOS camera, 1200s exposure [1],1500s exposure [2], [3] RC 500mm f=1.414m at Salvia Observatory (I73) equipped with ZWO6200MMPRO CMOS camera, 2400s exposure, [1][2][3] are equiped with RAPAS filters meeting the Gaia G, Gbp, Grp photometric bands. The FITS files are reduced with the Gaia photometric catalog in respective G, Gbp, Grp bands. The afterglow is detected RA(J2000) = 18h 14m 53.57s ; Dec(J2000) = +33° 26’ 20.4” ; ± 0.5’’ [1][2] At this location it is not detected, above the upper limit magnitude [3] MJD (mid) Gaia band mag.(Gaia) RAPAS station 60643.72986 G 20.50 ± 0.5 [1] 60644.77083 G 21.00 ± 0.5 [2] 60647.74270 G+Gbp+Grp >21. [3] RAPAS ( https://proam-gemini.fr/rapas/ ) is a new ProAm collaboration funded by Paris Observatory, delivering to a network of french amateur observatories a set of 3 filters meeting the Gaia spectral bands. This network is dedicated to deliver data in the Gaia photometric system on selected astrophysical alerts by Astro-COLIBRI ( https://astro-colibri.com/ ) or from Gaia alerts. View this GCN Circular online at https://gcn.nasa.gov/circulars/38438. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36432] GRB 241201A: GRBAlpha detection
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38437 SUBJECT: GRB 241201A: GRBAlpha detection DATE: 24/12/04 11:07:20 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. We report a possible detection of the long-duration GRB 241201A (Fermi/GBM detection: GCN 38403) by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract). We note that GRBAlpha did not detect the initial bright peak but only the secondary one ~10 s later. The Fermi/GBM location of this burst was not occulted by the Earth or Moon at the trigger time. The non-detection of the initial peak could be due to a significantly decreased effective area caused by the variable attitude of the satellite. The detection peak time is at 2024-12-01 14:56:06.7 UTC. The T90 duration measured by GRBAlpha is 1.5 s and the overall significance during T90 reaches 7.8 sigma. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB241201A_GCN.pdf All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. View this GCN Circular online at https://gcn.nasa.gov/circulars/38437. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36431] GRB 241204A: Fermi-LAT detection
by GCN Circulars 04 Dec '24

04 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38436 SUBJECT: GRB 241204A: Fermi-LAT detection DATE: 24/12/04 09:26:19 GMT FROM: Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi(a)ba.infn.it> E. Bissaldi (Politecnico and INFN Bari), A. Holzmann Airasca (UniTrento and INFN Bari) and T. Khalil (Johannesburg Univ) report on behalf of the Fermi-LAT Collaboration: On Dec 4, 2024, Fermi-LAT detected high-energy emission from GRB 241204A, which was also detected by Fermi-GBM (trigger 754976367 / 241204.152). The best LAT on-ground location is found to be: RA, Dec = 316.50, 6.55 (J2000), with an error radius of 0.5 deg (90 % containment, statistical error only). This was 26 deg from the LAT boresight at the time of the GBM trigger (T0 = 03:39:22.51 UT). The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0 - 350 s after the GBM trigger is (1.7 +/- 0.4) E-5 ph/cm2/s. The estimated photon index above 100 MeV is 2.8 +/- 0.4. The highest-energy photon is a 260 MeV event which is observed ~16 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Tamador Khalil (tamtam2030(a)gmail.com). 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/38436. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36430] EP241202b: Upper limits from Fermi-GBM Observations
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38435 SUBJECT: EP241202b: Upper limits from Fermi-GBM Observations DATE: 24/12/03 20:18:30 GMT FROM: mariaedvige.ravasio(a)ru.nl M. E. Ravasio (Radboud Univ.), E. Burns (LSU), P.G. Jonker (Radboud Univ.), and M. Hui (NASA MSFC) report on behalf of the Fermi-GBM Team: Fermi-GBM had full spatial and temporal coverage of the EP-WXT signal of EP241202b (Zhou et al., GCN 38426). There was no Fermi-GBM onboard trigger around the EP-WXT trigger time T0=2024-12-02 15:12:55 UTC. 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 trigger time, seeking signals between 64 ms and 32.768 s in duration. A transient was found, but its localization is not consistent with the EP transient’s one. No signal consistent both temporally and spatially is identified, as confirmed by visual inspection of the data. Assuming a “normal” spectral template (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3), whose alpha value is consistent with the power law index reported by EP (Zhou et al., GCN 38426), and a duration of 8.192 s, we derive a sky-averaged upper limit of 5.2e-08 erg/cm2/s in the energy band 10-1000 keV. [1] Goldstein et al. 2019 arXiv:1903.12597 View this GCN Circular online at https://gcn.nasa.gov/circulars/38435. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36429] IceCube-241127A: No transient candidates from the Zwicky Transient Facility
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38434 SUBJECT: IceCube-241127A: No transient candidates from the Zwicky Transient Facility DATE: 24/12/03 18:53:03 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (JSI), Sven Weimann (Ruhr University Bochum), Jannis Necker (DESY), Anna Franckowiak (Ruhr University Bochum) and Jesper Sollerman (Stockholm University) report: On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: As part of the ZTF neutrino follow up program (Stein et al. 2023), we observed the localization region of the neutrino event IceCube-241127A (Zegarelli et. al, GCN 38349) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). As a result of delays due to bad weather, we started observations in the g- and r-band beginning at 2024-11-29 10:38 UTC, approximately 44.4 hours after event time. We covered 95.5% (1.0 sq deg) of the reported localization region. This estimate accounts for chip gaps. Each exposure was 300s with a typical depth of 21.0 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019). We find one candidates lying within the 90.0% localization of the skymap. +---------------------------------------------------------------------------------+ | ZTF Name | IAU Name | RA (deg) | DEC (deg) | Filter | Mag | MagErr | +---------------------------------------------------------------------------------+ | ZTF19aasljeo | AT2022aelp | 163.5871140 | +05.9265829 | g | 19.23 | 0.14 | +---------------------------------------------------------------------------------+ ZTF19aasljeo is a nuclear source that was first detected on 2019-04-27, and has a long history of variability in ZTF. The source has a crossmatched detection as WISEA J105420.91+055535.5 at a distance of 0.25", and based on the WISE colours of the galaxy (W1-W2 = 1.07), ZTF19aasljeo is very likely an AGN. Over the past two months the source has been detected in difference imaging with a magnitude of g ~ 19.3. In historical detections over the past two years, the source was detected at a fainter level of g ~ 20. In reference science images from PS1 (Chambers et al. 2016), the source was detected at a much fainter level of g = 21.3, demonstrating that the source has brightened substantially in recent years. However, there are no indications of significant flaring on timescales of either weeks or months that coincide with the detection of IC241127A. We therefore find no strong evidence from our data to suggest that this AGN is associated with the neutrino. Observations of this field will continue as part of our standard ToO cadence for high-energy neutrinos (Stein et al. 2023). ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA; WIS, Israel; OKC, Sweden; JSI/UMd, USA; DESY, Germany; TANGO, Taiwan; UW Milwaukee, USA; LANL, USA; TCD, Ireland; IN2P3, France. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering is performed with the nuztf (Stein et al. 2021, https://github.com/desy-multimessenger/nuztf ). View this GCN Circular online at https://gcn.nasa.gov/circulars/38434. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36428] EP241202b: Kinder optical counterpart candidate
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38433 SUBJECT: EP241202b: Kinder optical counterpart candidate DATE: 24/12/03 17:35:31 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> C.-C. Ngeow (NCU), S. Yang (HNAS), A. Aryan, T.-W. Chen, Y. J. Yang, Y.-C. Cheng, M.-H. Lee, W.-J. Hou (all NCU), A. K. H. Kong (NTHU), S. J. Smartt (Oxford/QUB), J. Gillanders (Oxford), A. Sankar.K, Y.-H. Lee, H.-Y. Miao, Y.-C. Pan, C.-H. Lai, H.-C. Lin, H.-Y. Hsiao, C.-S. Lin, J.-K. Guo (all NCU), Z. N. Wang, 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 EP241202b (Zhou et al., GCN 38426) using the 1m LOT at the Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2024 arXiv:2406.09270). The first LOT epoch of observations started at 10:40 UTC on 3rd December 2024 (MJD 60647.444), 19.45 hr after the EP-WXT trigger. We utilized the Kinder pipeline (Yang et al. A&A 646, A22) to stack the images and visually identified a faint, plausible optical transient candidate at RA = 03:01:20.862, Dec = +02:26:27.04, approximately 2.11 arcminutes from the reported coordinates of EP241202b. To confirm this, we subtracted the stacked image from the DESI Legacy Survey (Dey et al. 2019) DR10 template images. The resulting difference image also revealed the trace of a tenuous source characterized by a well-defined Gaussian profile. The details of the observations and measured aperture magnitude without template subtraction (in the AB system) of the possible counterpart of EP241202b are as follows: -------------------------------------------------------------------------------------------------Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass LOT | r | 60647.444 | 19.45 | 300 * 6 | 22.41 +/- 0.16 | 1".51 | 1.56 Following the detection of the plausible optical counterpart candidate, we began another set of observations about 1.47 hr after the first set of observations. The optical counterpart candidate disappeared in the second set. The details of observations and measured 3-sigma upper limit for the second epoch of observations are as follows: -------------------------------------------------------------------------------------------------Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass LOT | r | 60647.524 | 21.36 | 300 * 6 | > 22.9 | 1".02 | 1.13 The plausible optical counterpart candidate has faded by 0.5 magnitudes over 1.9 hours; however, this variation could be attributed to statistical fluctuations, given the source's faintness. The presented magnitudes were calibrated using the field stars from the Pan-STARRS1 catalog (Chambers et al., 2016 arXiv:1612.05560) and were not corrected for the expected Galactic foreground extinction corresponding to a reddening of A_r = 0.21 mag in the direction of the transient (Schlafly & Finkbeiner 2011). Further follow-up observations are encouraged to confirm this candidate. View this GCN Circular online at https://gcn.nasa.gov/circulars/38433. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36427] Fermi-GBM Sub-Threshold Detection of GRB 241128A
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38432 SUBJECT: Fermi-GBM Sub-Threshold Detection of GRB 241128A DATE: 24/12/03 17:09:15 GMT FROM: rhamburg(a)usra.edu R. Hamburg (USRA) reports on behalf of the Fermi-GBM Team: The Swift-BAT detected GRB 241128A on 2024-11-28 at 16:14:34 UTC (Brivio et al. 2024, GCN 38367). There was no Fermi-GBM onboard trigger around this event time. An automated, blind search for gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no counterparts. The GBM Targeted Search [1], a sensitive and coherent search for subthreshold GRB-like signals, was run from +/-30 s around the Swift-BAT trigger time and identified a gamma-ray transient most significantly at 16:14:38 UTC (Fermi MET=754503283), about 4 s after the Swift-BAT trigger time. The transient is approximately 2 s in duration and was identified with the "normal" spectral template (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3) with FAR of 1.7e-4 Hz. The Targeted Search localization is consistent with the Swift-BAT location. [1] Goldstein et al. arXiv:1903.12597 View this GCN Circular online at https://gcn.nasa.gov/circulars/38432. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36426] GRB 241113B : RAPAS follow-up observation
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38431 SUBJECT: GRB 241113B : RAPAS follow-up observation DATE: 24/12/03 16:29:28 GMT FROM: Thierry Midavaine at GRANDMA <thierrymidavaine(a)sfr.fr> Thierry Midavaine on behalf of the RAPAS network reports (#2) : Patrick Martinez, Pascal André, David Bregou, David Fardin, Erik Guthleben [1] observed the Gamma-Ray Burst GRB241113B (N. Dagoneau et al. GCN 38196, D. Turpin et al. GCN 38330) using [1] ADAGIO N 820mm telescope f=3.1m at Belesta Observatory (IAU A05) equiped with a Moravian C3 CMOS camera, 25mn exposure, equiped with RAPAS filter meeting the Gaia G photometric band. The FITS file is reduced with the Gaia photometric catalog in respective G band. The afterglow is detected RA(J2000) = 07h20m55.30s ; Dec(J2000) = +46°48’13.1” Accy +/- 0.5“ [1] MJD(mid) Gaia band mag. accy RAPAS station 60642.92014 G 22.25 +/-0.5 [1] RAPAS ( https://proam-gemini.fr/rapas/ ) is a new ProAm collaboration funded by Paris Observatory, delivering to a network of french amateur observatories a set of 3 filters meeting the Gaia spectral bands. This network is dedicated to deliver data in the Gaia photometric system on selected astrophysical alerts by Astro-COLIBRI ( https://astro-colibri.com/ ) or from Gaia alerts. View this GCN Circular online at https://gcn.nasa.gov/circulars/38431. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36425] EP241201a: EP-FXT follow-up observations
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38430 SUBJECT: EP241201a: EP-FXT follow-up observations DATE: 24/12/03 15:57:18 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> W. Chen (NAO, CAS), G. Y. Zhao (SYSU), C. Zhou (HUST), T. Zhao (NAO, CAS), W. D. Zhang (NAO, CAS) report on behalf of the Einstein Probe team: Following the detection of the fast X-ray transient EP241201a (Chen et al., GCN 38415), we performed an observation with the Follow-up X-ray Telescope (FXT) on board the Einstein Probe mission. The observation started at 2024-12-02T09:23:55 (UTC), about 12 hours after the EP-WXT detection, with an exposure time of 2.9 ks. Within the WXT error circle, an uncatalogued X-ray source is detected at R.A. = 282.4865 deg, DEC = 66.0693 deg (J2000) with an uncertainty of 10 arcsec in radius (90% C.L. statistical and systematic). The average FXT spectrum in 0.5-10 keV can be fitted by an absorbed power law with a photon index of 4.8(-1.5,+1.7) and a column density of 1.2(-0.5,+0.6) x 10^22 cm^-2, giving an average unabsorbed flux of 2.9(-2.0, +14.4) x 10^-12 erg/s/cm^2 in the 0.5-10 keV band. Compared to the WXT detection, its flux has droped by about three orders of magnitude. The X-ray spectrum in 0.5-10 keV can also be fittted by an absorbed black body with a temperature of 0.27(-0.06, +0.08) keV and a column density of 4.9(-3.2, +4.0) x 10^21 cm^-2, giving an average unabsorbed flux of 3.9(-1.5, +3.7) x 10^-13 erg/s/cm^2. 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/38430. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36424] Konus-Wind detection of GRB 241130A
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38429 SUBJECT: Konus-Wind detection of GRB 241130A DATE: 24/12/03 12:50:12 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 long GRB 241130A (Fermi-GBM detection: The Fermi GBM team, GCN 38405, Sharma et al., GCN 38421; EIRSAT-1 GMOD Detection: McDermott et al., GCN 38423; IPN triangulation: Ridnaia et al., GCN 38424) triggered Konus-Wind (KW) at T0=83628.376 s UT (23:13:48.376). The burst light curve shows a single, FRED-like pulse, which starts at ~T0-0.5 s, peaks at ~T0+0.3 s, and has a total duration of ~10 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241130_T83628/ As observed by Konus-Wind, the burst had a fluence of (1.52 ± 0.21)x10^-5 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 0.384 s, of (1.77 ± 0.22)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.25(-0.08,+0.09) and Ep = 663(-128,+185) keV (chi2 = 66/81 dof). Fitting this spectrum by a Band function yields the same values of alpha and Ep, and an upper limit on the high energy photon index beta of -2.4 (chi2 = 66/80 dof). All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/38429. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36423] EP241202b: Global MASTER-Net observations report
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38428 SUBJECT: EP241202b: Global MASTER-Net observations report DATE: 24/12/03 11:18:21 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) was pointed to the EP241202b ( EP Team et al., GCN 38426) errorbox 11695 sec after notice time and 68974 sec after trigger time at 2024-12-03 10:22:29 UT, with upper limit up to 19.5 mag. Observations started at twilight. The observations began at zenith distance = 78 deg. The sun altitude is -11.9 deg. The galactic latitude b = -46 deg., longitude l = 175 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2693898 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 69004 | 2024-12-03 10:22:29 | MASTER-Tunka | (03h 01m 32.26s , +02d 12m 18.8s) | C | 60 | 17.9 | Coadd 70325 | 2024-12-03 10:44:30 | MASTER-Tunka | (03h 01m 32.36s , +02d 14m 44.8s) | C | 60 | 19.2 | 71945 | 2024-12-03 11:11:29 | MASTER-Tunka | (03h 01m 31.26s , +02d 15m 37.9s) | C | 60 | 19.4 | 72017 | 2024-12-03 11:12:41 | MASTER-Tunka | (03h 01m 26.53s , +02d 14m 42.3s) | C | 60 | 19.5 | 72090 | 2024-12-03 11:13:54 | MASTER-Tunka | (03h 01m 25.46s , +02d 15m 45.5s) | 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/38428. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36422] EP241201a: BOOTES-5 optical upper limit
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38427 SUBJECT: EP241201a: BOOTES-5 optical upper limit DATE: 24/12/03 10:36:32 GMT FROM: ipg(a)iaa.es I. Perez-Garcia, S.-Y. Wu, E. Fernandez-Garcia, M. D. Caballero-Garcia, G. Garcia-Segura, R. Sanchez-Ramirez, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), C. Perez del Pulgar, A. Castellon (Univ. de Malaga), Y.-D. Hu (INAF-OAB, Brera), L. Hernandez-Garcia (Univ. de Valparaiso), M. Gritsevich (Univ. of Helsinki), D. R. Xiong (Yunnan Observatories of CAS), S. Jeong (ADD, Daejeon) and D. Hiriart and W. H. Lee (UNAM), on behalf of a larger collaboration, report: Following the detection of the fast X-ray transient EP241201a by the Einstein Probe (Chen et al. GCNC [38415](https://gcn.nasa.gov/circulars/38415)), the 0.6m BOOTES-5 robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) observed the fast X-ray transient location starting on Dec 02, 05:32 UT (8.5 hours after trigger and 1 minute after notification) in different optical bands. No new optical source is detected on the co-added images (20*60 sec clear-filter) within the EP/WXT 3 arcmin radius error box down to 20.3 mag. Additionally, the source reported 4.8 hr later by Kinder (Lee et al, GCNC [38418](https://gcn.nasa.gov/circulars/38418)) is neither detected in our observation nor in the NOT one at a later epoch (Liu et al., GCNC [38425](https://gcn.nasa.gov/circulars/38425)). We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38427. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36421] EP241202b: EP detection of a fast X-ray transient
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38426 SUBJECT: EP241202b: EP detection of a fast X-ray transient DATE: 24/12/03 07:06:08 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> C. Zhou(HUST), G. Y. Zhao(SYSU), X. Mao, R. D. Liang, W. Yuan (NAO,CAS) report on behalf of the Einstein Probe team: We report on the detection of a fast X-ray transient detected by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, EP241202b (Obs. ID: 08500000223). The transient was first detected with WXT at around 2024-12-02 15:12:55 (UTC) and lasted for over 140 seconds. The WXT position of EP241202b is R.A.= 45.302 deg, DEC = 2.441 deg (J2000) with an uncertainty of 2.6 arcmin (radius, 90% C.L. statistical and systematic). It has a peak flux of 1.4 x 10^(-9) erg/s/cm^2 in the 0.5-4 keV band. The average 0.5-4 keV spectrum can be fitted with an absorbed power law with a photon index of 1.06 (+0.43/-0.41) (with a column density fixed at the Galactic value of 9.5 x 10^20 cm^-2). The derived average unabsorbed 0.5-4 keV flux is 5.4 (+2.0/-1.6) x 10^(-10) erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters. No previously known X-ray sources are found within the error circle around the source position. We plan to perform a target of opportunity observation with the Follow-up X-ray Telescope (FXT) on board EP. Further follow-up observations are encouraged to explore the origin of EP241202b. 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/38426. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36420] EP241201a: NOT optical observations
by GCN Circulars 03 Dec '24

03 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38425 SUBJECT: EP241201a: NOT optical observations DATE: 24/12/03 06:06:27 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> X. Liu, S.Q. Jiang, S.Y. Fu, Z.P. Zhu, J. An, D. Xu (NAOC), J.P.U. Fynbo (DAWN/NBI), A.H. de la Fuente, A.G. Theil (NOT) report: We observed the field of EP241201a detected by EP-WXT (Chen et al, GCN 38415) using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started at 2024-12-02T19:53:15, i.e., ~ 22.9 hrs after the EP-WXT trigger, and 5x200 s Sloan r-filter images were obtained. No reliable optical transient is found within the EP-WXT 2.34 arcmin error circle (Chen et al, GCN 38415) after performing image differencing using the DESI Legacy Survey as template, down to a 5-sigma upper limit of r > 22.5, calibrated with nearby Pan-STARRS stars and not corrected for Galactic extinction. In addition, the plausible optical transient candidate reported by Kinder (Lee et al, GCN 38418) is not present in our stacked image. View this GCN Circular online at https://gcn.nasa.gov/circulars/38425. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36419] IPN triangulation of GRB 241130A
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38424 SUBJECT: IPN triangulation of GRB 241130A DATE: 24/12/02 20:40:45 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, 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, and E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report: The long-duration GRB 241130A (Fermi-GBM detection: The Fermi GBM team, GCN 38405, Sharma et al., GCN 38421; EIRSAT-1 GMOD Detection: McDermott et al., GCN 38423) was detected by Fermi (GBM trigger 754701230), Konus-Wind, INTEGRAL (SPI-ACS), and EIRSAT-1 (GMOD) at about 83625 s UT (23:13:45). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 111.465 (07h 25m 52s) -31.442 (-31d 26' 30") Corners: 120.603 (08h 02m 25s) -25.812 (-25d 48' 42") 122.268 (08h 09m 04s) -26.450 (-26d 27' 01") 99.058 (06h 36m 14s) -35.673 (-35d 40' 23") 96.603 (06h 26m 25s) -34.608 (-34d 36' 30") --------------------------------------------- The error box area is 31 sq. deg, and its maximum dimension is 23.5 deg (the minimum one is 1.4 deg). The Sun distance was 108 deg. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM localization (GCN 38405). This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB241130_T83628/IPN The HEALPix triangulation map is the multi-order HEALPix 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/38424. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36418] GRB 241130A: EIRSAT-1 GMOD Detection
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38423 SUBJECT: GRB 241130A: EIRSAT-1 GMOD Detection DATE: 24/12/02 20:06:55 GMT FROM: Padraig McDermott at University College Dublin <padraig.mcdermott(a)ucdconnect.ie> P. McDermott, C. McKenna, D. Murphy, C. de Barra, A. Ulyanov, M. Doyle, R. Dunwoody, J. Mangan, G. Finneran, G. Corcoran, L. Cotter, A. Empey, J. Fisher, F. Gibson Kiely, J. Thompson, D. McKeown, A. Martin-Carrillo, L. Hanlon, S. McBreen, on behalf of the EIRSAT-1 team: EIRSAT-1 reports the detection of the long gamma-ray burst GRB241130A by the Gamma-ray Module (GMOD) instrument, which was also reported by Fermi GBM (GCN 38421 and 38406). The GMOD detection was made at 24-11-30 23:13:44.3 UTC. The GMOD light curve for GRB241130A, with 1.2s binning, shows a single peak. The spacecraft location at time of detection was 36.002 N, 21.890 W and an altitude of 453 km. The light curve for this event as measured by GMOD can be found here: https://grb.eirsat1.ie/241130A/241130A_LC_onboard_preliminary.png A bright FRED-like pulse can also be seen in the SPI-ACS ([Rau et al, Astronomy & Astrophysics, 438(3). 1175-1183. 2005](https://www.aanda.org/articles/aa/abs/2005/30/aa3159-05/aa3159-05.htm…) light curve at a consistent time (SPI-ACS data can be retrieved using the following [link](https://www.astro.unige.ch/mmoda/?DEC=-29.74516667&RA=265.97845833&T1=2024-11-30T23%3A10%3A00.000&T2=2024-11-30T23%3A20%3A00.000&T_format=isot&data_level=ordinary&instrument=spi_acs&product_type=spi_acs_lc&query_status=new&query_type=Real&selected_catalog=&src_name=1E+1740.7-2942&time_bin=0.2&time_bin_format=sec)). EIRSAT-1 is Ireland’s first satellite ([Doyle et al. Proceedings of the 4th SSEA, 2022](https://researchrepository.ucd.ie/bitstreams/2f3fdccb-6e36-4ac1-88cd-4e80feecf446/download)). It is a 2U CubeSat and carries onboard a number of experiments including the Gamma-Ray Module (GMOD), a novel, compact Gamma-ray detector ([Murphy et al, Experimental Astronomy, 53, 961–990, 2022](https://link.springer.com/article/10.1007/s10686-022-09842-z)). GMOD consists of a 25 mm × 25 mm × 40 mm Cerium Bromide scintillator coupled to SiPMs and is designed to detect gamma-ray bursts in the ~ 60 keV - 1.5 MeV range. EIRSAT-1 was developed in University College Dublin with support from ESA’s Fly Your Satellite! programme and was launched on 1st December 2023. View this GCN Circular online at https://gcn.nasa.gov/circulars/38423. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36416] GRB 241128A: Swift/UVOT Upper Limits
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38422 SUBJECT: GRB 241128A: Swift/UVOT Upper Limits DATE: 24/12/02 19:11:35 GMT FROM: Sam Shilling at Lancaster University <shilling.sam(a)gmail.com> S.P.R. Shilling (Lancaster U.) and Brivio (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 241128A 3880 s after the BAT trigger (Brivio et al., GCN Circ. 38367). No optical afterglow consistent with the enhanced XRT position (Beardmore et al., GCN Circ. 38374) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 3880 4029 147 >20.0 white 3880 4649 344 >20.6 v 4860 5059 197 >19.0 b 4244 4444 197 >19.7 u 4038 4238 197 >19.2 m2 5065 10054 534 >19.4 w2 4655 4855 197 >19.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.067 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/38422. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36417] GRB 241128A: Swift/UVOT Upper Limits
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38422 SUBJECT: GRB 241128A: Swift/UVOT Upper Limits DATE: 24/12/02 19:11:35 GMT FROM: Sam Shilling at Lancaster University <shilling.sam(a)gmail.com> S.P.R. Shilling (Lancaster U.) and Brivio (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 241128A 3880 s after the BAT trigger (Brivio et al., GCN Circ. 38367). No optical afterglow consistent with the enhanced XRT position (Beardmore et al., GCN Circ. 38374) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 3880 4029 147 >20.0 white 3880 4649 344 >20.6 v 4860 5059 197 >19.0 b 4244 4444 197 >19.7 u 4038 4238 197 >19.2 m2 5065 10054 534 >19.4 w2 4655 4855 197 >19.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.067 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/38422. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36415] GRB 241130A: Fermi GBM Detection
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38421 SUBJECT: GRB 241130A: Fermi GBM Detection DATE: 24/12/02 18:25:13 GMT FROM: Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma(a)nasa.gov> V Sharma (NASA GSFC/UMBC), O.J. Roberts (NASA/MSFC) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 23:13:45.38 UT on 30 November 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241130A (trigger 754701230/241130968). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 100.29, Dec = -26.38 (J2000 degrees, equivalent to J2000 6h 41m, -26d 22'), with a statistical uncertainty of 1.00 degrees. (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a mixture of two Gaussians, one with a radius of 1.8 degrees (52% contribution) and one with a radius of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]). The angle from the Fermi LAT boresight is 95 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 4.6 s (50-300 keV). The time-averaged spectrum from T0+0 to T0+4.544 s is best fit by a Band function with Epeak = 320 +/- 30 keV, alpha = -0.92 +/- 0.04, and beta = -2.04 +/- 0.07. The event fluence (10-1000 keV) in this time interval is (1.09 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.22 s in the 10-1000 keV band is 33.6 +/- 0.5 ph/s/cm^2. 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/38421. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36414] IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38420 SUBJECT: IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube DATE: 24/12/02 17:19:50 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites(a)wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-241127A (https://gcn.nasa.gov/circulars/38349) in a time range of 1000 seconds centered on the alert event time (2024-11-27 14:02:54.420 UTC to 2024-11-27 14:19:34.420 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-241127A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-241127A is 1.4e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 1e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2024-11-26 14:11:14.420 UTC to 2024-11-28 14:11:14.420 UTC). In this case, we report a p-value of 1.00, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-241127A is 1.6e-01 GeV cm^-2 in a 2 day time window. 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] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021) View this GCN Circular online at https://gcn.nasa.gov/circulars/38420. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36413] GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38419 SUBJECT: GRB 241129A: Swift/BAT-GUANO localization skymap of a burst DATE: 24/12/02 17:11:37 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 241129A onboard (T0: 2024-11-29T01:31:33.42 UTC, Fermi trig 754536698) 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 BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 10.58 in a 16.384 s analysis time bin, starting at T0 - 4.096 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2024. in prep) The 90% credible area is 411 deg2 and the 50% credible area is 96 deg2. The integrated probability inside the coded field of view is <1%. The NITRATES skymap is consistent with the Fermi localization reported in the final position notice (GCN 38375). The combined Fermi/GBM+NITRATES 90% credible area is 145 deg2 and the 50% credible area is 45 deg2. A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=754536728/#:~:te… The probability skymap file can be downloaded from the link here [skymap_fits_file](https://guano.swift.psu.edu/files/754536728/0_n_PROBMAP) Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=754536728 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/38419. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36412] EP241201a: Kinder optical counterpart candidate
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38418 SUBJECT: EP241201a: Kinder optical counterpart candidate DATE: 24/12/02 15:45:07 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> M.-H. Lee (NCU), S. Yang (HNAS), A. Aryan, T.-W. Chen, Y. J. Yang, W.-J. Hou (all NCU), S. J. Smartt (Oxford/QUB), A. K. H. Kong (NTHU), J. Gillanders (Oxford), C.-C. Ngeow, A. Sankar.K, Y.-H. Li, H.-Y. Miao, Y.-C. Pan, C.-H. Lai, H.-C. Lin, H.-Y. Hsiao, C.-S. Lin, J.-K. Guo (all NCU), Z. N. Wang, 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 EP241201a (Chen et al., GCN 38415) using the 1m LOT at the Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2024 arXiv:2406.09270). The first LOT epoch of observations started at 10:25 UTC on 2nd December 2024 (MJD 60646.434), 13.40 hr after the EP-WXT trigger. We utilized the Kinder pipeline (Yang et al. A&A 646, A22) to stack the images and subtract them from the DESI Legacy Survey (Dey et al. 2019) DR10 template images. Although no definitive candidates were detected in the difference images, we conducted a manual inspection of both the target and difference images. During this process, we identified a plausible optical transient candidate at RA=18:50:38.079, Dec=+66:03:11.36, located approximately 2.28 arcminutes from the reported coordinates of EP241201a. Despite the low signal-to-noise ratio (SNR) of this candidate, we believe it to be real due to its well-defined Gaussian profile. The details of the observations and measured PSF magnitude with template subtraction (in the AB system) of the possible counterpart of EP241201a are as follows: --------------------------------------------------------------------------------------------------Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass LOT | r | 60646.434 | 13.40 | 300 * 6 | 22.69 +/- 0.41 | 1".43 | 2.06 The presented magnitude was calibrated using the field stars from the Pan-STARRS1 catalog (Chambers et al., 2016 arXiv:1612.05560) and was not corrected for the expected Galactic foreground extinction corresponding to a reddening of A_r = 0.13 mag in the direction of the transient (Schlafly & Finkbeiner 2011). We note an extended source in the Legacy Survey image 5".8 west and 3".8 south from the plausible optical transient candidate, at RA=18:50:37.128, Dec=+66:03:07.56, is possibly its host galaxy, with r-band magnitude as 20.47 mag and photo-z = 0.313 +/- 0.056, the distance module is then 40.91. Assuming the r-band can be roughly K-corrected to the g-band, with the Milky Way extinction correction, the optical counterpart candidate has the rest-frame M_g = -18.35 mag. Further follow-up observations are encouraged to confirm this candidate, as it is beyond our 3-sigma detection limit of r > 21.6 mag. View this GCN Circular online at https://gcn.nasa.gov/circulars/38418. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36411] EP241201a: Kinder optical counterpart candidate
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38418 SUBJECT: EP241201a: Kinder optical counterpart candidate DATE: 24/12/02 15:45:07 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> M.-H. Lee (NCU), S. Yang (HNAS), A. Aryan, T.-W. Chen, Y. J. Yang, W.-J. Hou (all NCU), S. J. Smartt (Oxford/QUB), A. K. H. Kong (NTHU), J. Gillanders (Oxford), C.-C. Ngeow, A. Sankar.K, Y.-H. Li, H.-Y. Miao, Y.-C. Pan, C.-H. Lai, H.-C. Lin, H.-Y. Hsiao, C.-S. Lin, J.-K. Guo (all NCU), Z. N. Wang, 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 EP241201a (Chen et al., GCN 38415) using the 1m LOT at the Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2024 arXiv:2406.09270). The first LOT epoch of observations started at 10:25 UTC on 2nd December 2024 (MJD 60646.434), 13.40 hr after the EP-WXT trigger. We utilized the Kinder pipeline (Yang et al. A&A 646, A22) to stack the images and subtract them from the DESI Legacy Survey (Dey et al. 2019) DR10 template images. Although no definitive candidates were detected in the difference images, we conducted a manual inspection of both the target and difference images. During this process, we identified a plausible optical transient candidate at RA=18:50:38.079, Dec=+66:03:11.36, located approximately 2.28 arcminutes from the reported coordinates of EP241201a. Despite the low signal-to-noise ratio (SNR) of this candidate, we believe it to be real due to its well-defined Gaussian profile. The details of the observations and measured PSF magnitude with template subtraction (in the AB system) of the possible counterpart of EP241201a are as follows: --------------------------------------------------------------------------------------------------Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass LOT | r | 60646.434 | 13.40 | 300 * 6 | 22.69 +/- 0.41 | 1".43 | 2.06 The presented magnitude was calibrated using the field stars from the Pan-STARRS1 catalog (Chambers et al., 2016 arXiv:1612.05560) and was not corrected for the expected Galactic foreground extinction corresponding to a reddening of A_r = 0.13 mag in the direction of the transient (Schlafly & Finkbeiner 2011). We note an extended source in the Legacy Survey image 5".8 west and 3".8 south from the plausible optical transient candidate, at RA=18:50:37.128, Dec=+66:03:07.56, is possibly its host galaxy, with r-band magnitude as 20.47 mag and photo-z = 0.313 +/- 0.056, the distance module is then 40.91. Assuming the r-band can be roughly K-corrected to the g-band, with the Milky Way extinction correction, the optical counterpart candidate has the rest-frame M_g = -18.35 mag. Further follow-up observations are encouraged to confirm this candidate, as it is beyond our 3-sigma detection limit of r > 21.6 mag. View this GCN Circular online at https://gcn.nasa.gov/circulars/38418. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36410] LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38417 SUBJECT: LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations DATE: 24/12/02 12:09:28 GMT FROM: Andrea Reguitti at INAF - Osservatorio Astronomico di Brera <andreareguitti(a)gmail.com> *A. Reguitti (INAF-OABr / INAF-OAPd), P. D’Avanzo (INAF-OAB), L. Tomasella (INAF-OAPd), Y. Hu (INAF-OABr), A. Rossi (INAF-OAS), E. Cappellaro (INAF-OAPd) et al. on behalf of the GRAWITA collaboration* We carried out optical follow-up observations of the well-localized LIGO/Virgo/KAGRA GW trigger S241102br (LVK Collaboration, GCN #38043) with the Schmidt telescope sited at the INAF Asiago observatory (Italy). Observations started on 2024-11-02 at 17:08 UT (~4.5 hours after the GW trigger) with the Sloan-r filter. We covered 12 square degrees within the 90% localisation region of the S241102br GW event, almost covering the totality of the final 7 deg2 50% localisation region. The 12 pointings of 1 square degree each are centered at J2000 celestial coordinates: (344.4023, 38.1139); (344.3944, 39.0544); (344.3862, 39.9948); (344.3775, 40.9352); (344.3684, 41.8757); (344.3589, 42.8161); (345.6411, 42.8161); (345.6316, 41.8757); (345.6225, 40.9352); (345.6138, 39.9948); (345.6056, 39.0544); (345.5977, 38.1139). These observations covered ~ 43% of the final 90% credible region (LVK Collaboration, GCN #38043). The typical 3 sigma limiting AB magnitudes are r ~ 21.1 mag. Preliminary analysis, which includes image subtraction with the template images from the PanSTARRS all-sky survey, shows no clear candidate counterparts. We carried out a specific search for transients in the galaxies located within the S241102br volume. We note that one of the NED galaxies (Cook et al. 2024, GCN #38044) at z = 0.08, a distance consistent with the estimation for the S241102br GW event (0.069<z<0.093), has been proposed in the past as the host galaxy of GRB 051109B (Perley et al. 2006, GCN #5387). We thank the staff at Padova Astronomical Observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38417. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36409] EP241201a: Global MASTER-Net observations report
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38416 SUBJECT: EP241201a: Global MASTER-Net observations report DATE: 24/12/02 10:27:31 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) was pointed to the EP241201a ( EP Team et al., GCN 38415) errorbox 10284 sec after notice time and 48020 sec after trigger time at 2024-12-02 10:21:42 UT, with upper limit up to 19.5 mag. Observations started at twilight. The observations began at zenith distance = 28 deg. The sun altitude is -11.8 deg. The galactic latitude b = 25 deg., longitude l = 96 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2692013 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 48028 | 2024-12-02 10:21:42 | MASTER-Tunka | (18h 51m 35.06s , +66d 13m 05.0s) | C | 15 | 19.0 | 48056 | 2024-12-02 10:22:09 | MASTER-Tunka | (18h 51m 34.90s , +66d 14m 05.6s) | C | 15 | 19.0 | 48091 | 2024-12-02 10:22:38 | MASTER-Tunka | (18h 51m 40.39s , +66d 13m 06.2s) | C | 30 | 19.5 | 48133 | 2024-12-02 10:23:20 | MASTER-Tunka | (18h 51m 35.74s , +66d 12m 06.9s) | C | 30 | 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/38416. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36408] EP241201a: EP detection of a fast X-ray transient
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38415 SUBJECT: EP241201a: EP detection of a fast X-ray transient DATE: 24/12/02 07:27:17 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> W. Chen, T. Zhao(NAO,CAS), C. Zhou(HUST), G. Y. Zhao(SYSU), W. D. Zhang(NAO,CAS) report on behalf of the Einstein Probe team: We report the detection of an X-ray transient EP241201a by EP-WXT, which triggered the on-board processing unit at 2024-12-01T21:01:22 (UTC) (trigger ID: 01709126276). We analysed the telemetry data of WXT, and found in the lightcurve a fast X-ray flare that started at 2024-12-01T20:59:16 (UTC) and lasted for about 230 seconds. The position is R.A. = 282.596 deg, DEC = 66.081 deg (J2000) with an uncertainty of about 2.343 arcmin (radius, 90% C.L. statistical and systematic). The average 0.5-4 keV spectrum that was extracted from the time interval of the flare can be fitted with an absorbed power law with a photon index of 3.9(-1.4,+1.6) and a column density of 1.5(-0.6,+0.8)e22 cm^-2. The unabsorbed flux in 0.5-4 keV is 7.1(-4.9,+32.7)e-9 erg/s/cm^2. We plan to perform a target of opportunity observation with the Follow-up X-ray Telescope (FXT) on board EP. Further follow-up observations are encouraged to explore the orgin of EP241201a. 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/38415. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36407] The EP-WXT trigger 01709126243 is not a real source
by GCN Circulars 02 Dec '24

02 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38414 SUBJECT: The EP-WXT trigger 01709126243 is not a real source DATE: 24/12/02 01:38:36 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> H.-Q. Cheng (NAO, CAS), S. X. Wen (NAO, CAS), A. Li (BNU), H. N. Yang (NAO, CAS), H. W. Pan (NAO, CAS) on behalf of the Einstein Probe team Further analysis of the late arrived telemetry data verifies that the EP-WXT on-board trigger 01709126243 at 2024-12-01T05:24:55 UTC is not a real source. View this GCN Circular online at https://gcn.nasa.gov/circulars/38414. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36406] GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38413 SUBJECT: GRB 241127B: detection of a long GRB by SVOM/ECLAIRs DATE: 24/12/01 22:27:09 GMT FROM: miguel.llamas.lanza(a)gmail.com SVOM/ECLAIRs Commissioning Team: Jean-Luc Atteia, Laurent Bouchet, Marius Brunet, Sebastien Guillot, Juliette Alaux, Hui Yang (IRAP), Stéphane Schanne, Damien Turpin, Nicolas Dagoneau, Frédéric Chateau, Hervé Le Provost (CEA), Wenjin Xie, Donghua Zhao (NAOC), Floriane Cangemi (APC), Tais Maiolino (LUPM), 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 comissioning phase, the SVOM/ECLAIRs telescope detected and localized a long duration GRB (GRB 241127B) at 2024-11-27T20:56:28.248 UT (Tb) through an offline search with the event-by-event data downloaded through the X-band ground station. The burst was detected by several methods and within several energy ranges and timescales. The best detection is obtained by the Wavelet Count-Rate trigger with a signal-to-noise ratio of 55.5 within 4-120 keV over a time window of 20.48 seconds starting at Tb. The lightcurve shows a slow rise of about 50 seconds and a faster decay of about 20 seconds. The localization of the best Alert is RA, Dec = 10.9757, 17.8559 (J2000).The statistical uncertainty on this position is 1.4 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature. SVOM did not slew on this burst. The ECLAIRs onboard trigger was not activated at the time of the burst. The burst is also observed in SVOM/GRM. 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: Miguel Llamas Lanza (IRAP) miguel.llamas.lanza(a)irap.omp.eu View this GCN Circular online at https://gcn.nasa.gov/circulars/38413. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36405] GRB241201B: Fermi GBM Final Localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38412 SUBJECT: GRB241201B: Fermi GBM Final Localization DATE: 24/12/01 22:15:58 GMT FROM: Bagrat Mailyan at Florida Tech <mbagrat(a)gmail.com> The Fermi GBM team reports the detection of a likely SHORT GRB "At 13:32:00.63 UT on 01 December 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB241201B (trigger 754752725/241201564). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 333.26, Dec = 38.75 (J2000 degrees, equivalent to J2000 22h 13m, +38d 45'), with a statistical uncertainty of 20.18 degrees. The angle from the Fermi LAT boresight is 74 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201564/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201564/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201564/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/38412. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36404] GRB241201B: Fermi GBM Final Localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38411 SUBJECT: GRB241201B: Fermi GBM Final Localization DATE: 24/12/01 22:15:15 GMT FROM: Bagrat Mailyan at Florida Tech <mbagrat(a)gmail.com> The Fermi GBM team reports the detection of a likely SHORT GRB "At 13:32:00.63 UT on 01 December 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB241201B (trigger 754752725/241201564). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 333.26, Dec = 38.75 (J2000 degrees, equivalent to J2000 22h 13m, +38d 45'), with a statistical uncertainty of 20.18 degrees. The angle from the Fermi LAT boresight is 74 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201564/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201564/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201564/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/38411. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36403] LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38410 SUBJECT: LIGO/Virgo/KAGRA S241201ac: Updated Sky localization DATE: 24/12/01 21:50:44 GMT FROM: ethan.payne(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further offline 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 S241201ac (GCN Circular 38402). 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/S241201ac For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 2300 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 7122 +/- 2366 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/38410. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36402] EP241126a: SOAR observations of the optical counterpart
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38409 SUBJECT: EP241126a: SOAR observations of the optical counterpart DATE: 24/12/01 21:45:36 GMT FROM: James Freeburn at Swinburne University of Technology <jamesfreeburn54(a)gmail.com> J. Freeburn (Swinburne/OzGrav), I. Andreoni (UNC), J. Carney (UNC) We observed the optical counterpart to the X-ray transient, EP241126a (Hu et al., GCN 38335; Zheng et al., GCN 38339), with the Goodman High Throughput Spectrograph mounted on the SOAR telescope in imaging mode. We took three 300s exposures in r-band between 2024-11-28T03:48:34 and 2024-11-28T04:07:23 UTC corresponding to ~32 hours after the initial trigger. We detect the optical counterpart associated with EP241126a (Fu et al., GCN 38337; Li et al., GCN 38338; Geng et al., GCN 38357; Qiu et al., GCN 38378; Malesani et al., GCN 38385; Zou, GCN 38404). With photometric calibration using the Pan-STARRS1 catalogue, we measure r= 23.325 +/- 0.090 AB magnitude. View this GCN Circular online at https://gcn.nasa.gov/circulars/38409. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36401] Fermi GRB 241201A: Global MASTER-Net observations report
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38408 SUBJECT: Fermi GRB 241201A: Global MASTER-Net observations report DATE: 24/12/01 20:00:43 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 Fermi GRB 241201A ( Fermi GBM team, GCN 38403) errorbox 14079 sec after notice time and 14110 sec after trigger time at 2024-12-01 18:51:09 UT, with upper limit up to 19.9 mag. The observations began at zenith distance = 79 deg. The sun altitude is -53.3 deg. The galactic latitude b = 63 deg., longitude l = 275 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2691073 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 14141 | 2024-12-01 18:51:09 | MASTER-Tunka | (11h 48m 39.15s , +06d 53m 47.2s) | C | 60 | 19.3 | 14201 | 2024-12-01 18:51:09 | MASTER-Tunka | (11h 48m 39.15s , +06d 53m 47.2s) | C | 180 | 19.8 | Coadd 14579 | 2024-12-01 18:58:27 | MASTER-Tunka | (11h 46m 11.74s , +05d 01m 12.0s) | C | 60 | 19.0 | 14639 | 2024-12-01 18:58:27 | MASTER-Tunka | (11h 46m 11.73s , +05d 01m 12.1s) | C | 180 | 19.6 | Coadd 14728 | 2024-12-01 19:00:56 | MASTER-Tunka | (11h 55m 50.65s , +06d 54m 27.7s) | C | 60 | 19.4 | 14788 | 2024-12-01 19:00:56 | MASTER-Tunka | (11h 55m 50.64s , +06d 54m 27.8s) | C | 180 | 19.8 | Coadd 14956 | 2024-12-01 19:04:45 | MASTER-Tunka | (12h 03m 54.69s , +06d 53m 20.5s) | C | 60 | 19.2 | 15016 | 2024-12-01 19:04:45 | MASTER-Tunka | (12h 03m 54.67s , +06d 53m 20.7s) | C | 180 | 19.8 | Coadd 15029 | 2024-12-01 19:05:58 | MASTER-Tunka | (11h 48m 42.69s , +06d 54m 06.9s) | C | 60 | 19.2 | 15322 | 2024-12-01 19:10:50 | MASTER-Tunka | (11h 46m 08.97s , +05d 00m 58.9s) | C | 60 | 19.4 | 15468 | 2024-12-01 19:13:16 | MASTER-Tunka | (11h 55m 58.43s , +06d 54m 49.9s) | C | 60 | 19.5 | 15541 | 2024-12-01 19:14:30 | MASTER-Tunka | (11h 53m 27.89s , +05d 00m 10.0s) | C | 60 | 19.5 | 15601 | 2024-12-01 19:14:30 | MASTER-Tunka | (11h 53m 27.89s , +05d 00m 09.9s) | C | 180 | 19.9 | Coadd 15613 | 2024-12-01 19:15:41 | MASTER-Tunka | (12h 01m 27.44s , +05d 01m 21.4s) | C | 60 | 19.3 | 15673 | 2024-12-01 19:15:41 | MASTER-Tunka | (12h 01m 27.43s , +05d 01m 21.6s) | C | 180 | 19.9 | Coadd 15685 | 2024-12-01 19:16:53 | MASTER-Tunka | (12h 03m 58.03s , +06d 53m 52.1s) | C | 60 | 19.4 | 16624 | 2024-12-01 19:32:32 | MASTER-Tunka | (11h 46m 08.42s , +05d 02m 28.5s) | C | 60 | 19.3 | 16696 | 2024-12-01 19:33:45 | MASTER-Tunka | (11h 55m 58.00s , +06d 55m 15.8s) | C | 60 | 19.6 | 16769 | 2024-12-01 19:34:57 | MASTER-Tunka | (11h 53m 21.59s , +05d 00m 20.6s) | C | 60 | 19.5 | 16842 | 2024-12-01 19:36:10 | MASTER-Tunka | (12h 01m 30.45s , +05d 00m 28.6s) | C | 60 | 19.3 | 16914 | 2024-12-01 19:37:23 | MASTER-Tunka | (12h 03m 57.99s , +06d 56m 01.3s) | C | 60 | 19.5 | 17358 | 2024-12-01 19:44:46 | MASTER-Tunka | (11h 44m 31.08s , +03d 07m 24.0s) | C | 60 | 19.5 | 17430 | 2024-12-01 19:45:59 | MASTER-Tunka | (11h 53m 27.91s , +05d 02m 25.5s) | C | 60 | 19.6 | 17503 | 2024-12-01 19:47:11 | MASTER-Tunka | (12h 01m 23.85s , +05d 01m 30.2s) | C | 60 | 19.6 | 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/38408. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36400] GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38407 SUBJECT: GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622) DATE: 24/12/01 17:22:52 GMT FROM: Jochen Greiner at MPE <jcg(a)mpe.mpg.de> T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 754757764 at 14:55:59 on 01 Dec. 2024 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position is: RA(2000.0) = 189.8 deg Decl.(2000.0) = -0.7 deg The 1 sigma statistical error radius is 2.6 deg. We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB241201622/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB241201622/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB241201622/json View this GCN Circular online at https://gcn.nasa.gov/circulars/38407. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36399] GRB 241130A: Fermi GBM Final Real-time Localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38406 SUBJECT: GRB 241130A: Fermi GBM Final Real-time Localization DATE: 24/12/01 17:11:32 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 23:13:45 UT on 30 Nov 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241130A (trigger 754701230.37592 / 241130968). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 100.3, Dec = -26.4 (J2000 degrees, equivalent to J2000 06h 41m, -26d 23'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 95.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241130968/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241130968/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241130968/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38406. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36398] GRB 241130A: Fermi GBM Final Real-time Localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38405 SUBJECT: GRB 241130A: Fermi GBM Final Real-time Localization DATE: 24/12/01 16:32:34 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 23:13:45 UT on 30 Nov 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241130A (trigger 754701230.37592 / 241130968). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 100.3, Dec = -26.4 (J2000 degrees, equivalent to J2000 06h 41m, -26d 23'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 95.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241130968/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241130968/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241130968/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38405. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36397] EP241126a: 1.6m Mephisto Optical Upper Limits
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38404 SUBJECT: EP241126a: 1.6m Mephisto Optical Upper Limits DATE: 24/12/01 15:38:10 GMT FROM: Brajesh Kumar at SWIFAR, YNU <brajesh(a)ynu.edu.cn> Xingzhu Zou, Helong Guo, Xinlei Chen, Yu Pan, Yaosong Yu, Guowang Du, Xufeng Zhu, Tao Wang, Brajesh Kumar, Yuan Fang, Jinghua Zhang, Yuanpei Yang, Xiangkun Liu, Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team: The field of fast X-ray transient EP241126a (Hu et al., GCN 38335; Zheng et al., GCN 38339) was observed with the 1.6m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University located at Lijiang Observatory. The observations were carried out in the v and r bands, ~15.8 hours after the EP trigger. We do not detect the optical counterpart (Fu et al., GCN 38337; Li et al., GCN 38338; Geng et al., GCN 38357; Qiu et al., GCN 38378; Malesani et al., GCN 38385) in the stacked images (total exposure 420 sec in each band). The 3-sigma upper limits in v and r bands (mid-UT 2024-11-27T11:28:36) are 22.2 and 22.3 mag respectively, which is consistent with Lai et al. (GCN 38344). ----------------------------------------------------------------------- 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/38404. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36396] GRB 241201A: Fermi GBM Final Real-time Localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38403 SUBJECT: GRB 241201A: Fermi GBM Final Real-time Localization DATE: 24/12/01 15:06:28 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 14:55:59 UT on 1 Dec 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241201A (trigger 754757764.155878 / 241201622). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 179.9, Dec = 3.2 (J2000 degrees, equivalent to J2000 11h 59m, 3d 12'), with a statistical uncertainty of 2.6 degrees. The angle from the Fermi LAT boresight is 26.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201622/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201622/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241201622/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38403. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36395] LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38402 SUBJECT: LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate DATE: 24/12/01 06:44:24 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241201ac during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-12-01 05:57:58.628 UTC (GPS time: 1417067896.628). The candidate was found by the cWB BBH [1] and GstLAL [2] analysis pipelines. S241201ac is an event of interest because its false alarm rate, as estimated by the online analysis, is 4.3e-08 Hz, or about one in 8 months. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241201ac The classification of the GW signal, in order of descending probability, is BBH (97%), Terrestrial (3%), NSBH (<1%), or BNS (<1%). Transient noise was present in the Virgo detector data at the time of the candidate, which may affect the parameters or 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%. [3] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [3] 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 4%. 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 [4], distributed via GCN notice about 28 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [4], 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 3425 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 9495 +/- 2984 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] T. Mishra et al. PRD 105, 083018 (2022) doi:10.1103/PhysRevD.105.083018 [2] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [3] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [4] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38402. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36394] LIGO/Virgo/KAGRA S241130be: Updated Sky localization
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38401 SUBJECT: LIGO/Virgo/KAGRA S241130be: Updated Sky localization DATE: 24/12/01 06:23:21 GMT FROM: ethan.payne(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 S241130be (GCN Circular 38393). 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/S241130be For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 1069 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1226 +/- 321 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/38401. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36393] Fermi trigger No 754701230: Global MASTER-Net observations report
by GCN Circulars 01 Dec '24

01 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38400 SUBJECT: Fermi trigger No 754701230: Global MASTER-Net observations report DATE: 24/12/01 01:30:42 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB241130.97 (trigger No 754701230,06h 41m 09.60s , -26d 22m 48.0s, R=1) errorbox 80 sec after notice time and 90 sec after trigger time at 2024-11-30 23:15:15 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 18 deg. The sun altitude is -35.0 deg. The galactic latitude b = -13 deg., longitude l = 236 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2690291 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 100 | 2024-11-30 23:15:15 | MASTER-SAAO | (06h 36m 22.91s , -27d 23m 19.4s) | C | 20 | 18.6 | 125 | 2024-11-30 23:15:15 | MASTER-SAAO | (06h 36m 22.91s , -27d 23m 19.4s) | C | 70 | 19.2 | Coadd 140 | 2024-11-30 23:15:55 | MASTER-SAAO | (06h 36m 22.98s , -27d 23m 19.1s) | C | 20 | 18.6 | 184 | 2024-11-30 23:16:34 | MASTER-SAAO | (06h 36m 23.00s , -27d 23m 18.6s) | C | 30 | 18.8 | 238 | 2024-11-30 23:17:23 | MASTER-SAAO | (06h 36m 23.05s , -27d 23m 18.2s) | C | 40 | 19.0 | 293 | 2024-11-30 23:17:23 | MASTER-SAAO | (06h 36m 23.05s , -27d 23m 18.3s) | C | 150 | 19.5 | Coadd 302 | 2024-11-30 23:18:22 | MASTER-SAAO | (06h 36m 23.09s , -27d 23m 17.4s) | C | 50 | 19.1 | 376 | 2024-11-30 23:19:31 | MASTER-SAAO | (06h 36m 23.12s , -27d 23m 16.5s) | C | 60 | 19.2 | 619 | 2024-11-30 23:23:34 | MASTER-SAAO | (06h 39m 55.86s , -26d 37m 24.9s) | C | 60 | 19.1 | 679 | 2024-11-30 23:23:34 | MASTER-SAAO | (06h 39m 55.87s , -26d 37m 24.9s) | C | 180 | 19.5 | Coadd 698 | 2024-11-30 23:24:53 | MASTER-SAAO | (06h 39m 55.95s , -26d 37m 24.4s) | C | 60 | 19.1 | 777 | 2024-11-30 23:26:12 | MASTER-SAAO | (06h 39m 56.00s , -26d 37m 23.4s) | C | 60 | 19.1 | 856 | 2024-11-30 23:27:31 | MASTER-SAAO | (06h 39m 56.01s , -26d 37m 22.4s) | C | 60 | 19.2 | 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/38400. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36392] IPN triangulation of GRB 241128B
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38399 SUBJECT: IPN triangulation of GRB 241128B DATE: 24/11/30 21:38:39 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 MGNS/BepiColombo and HEND/Mars Odyssey teams, J. Benkhoff on behalf of the BepiColombo team, D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, E. Burns on behalf of the IPN, 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 bright, long-duration GRB 241128B (SVOM-GRM detection: Xue et al., GCN 38389) Konus-Wind, INTEGRAL (SPI-ACS), SVOM (GRM), Mars-Odyssey (HEND), and BepiColombo (MGNS), at about 19346 s UT (05:22:26). We have triangulated it to a preliminary, 3 sigma error region whose area is 880 sq. arcmin, and its maximum dimension is 7.9 deg (the minimum one is 2.1 arcmin). This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB241128_T19346/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/38399. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36391] Konus-Wind detection of GRB 241114B
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38398 SUBJECT: Konus-Wind detection of GRB 241114B DATE: 24/11/30 21:32:42 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 241114B (Insight-HXMT-HE detection: Wang et al., GCN 38284; IPN triangulation: Svinkin et al., GCN 38341) triggered Konus-Wind at T0=39903.659 s UT (11:05:03.659). The burst light curve shows a multipeaked structure which starts at ~T0-11.7 s and has a total duration of ~45 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241114_T39903/ As observed by Konus-Wind, the burst had a fluence of 4.03(-0.38,+0.43)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+23.648 s, of 1.38(-0.22,+0.24)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+32.768 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 = -1.15(-0.10,+0.11), the high energy photon index beta = -3.11(-6.89,+0.49), the peak energy Ep = 258(-25,+30) keV (chi2 = 123/97 dof). The spectrum near the maximum count rate (measured from T0+16.640 s to T0+24.576 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 = -0.76(-0.14,+0.17), the high energy photon index beta = -3.08(-6.92,+0.46), the peak energy Ep = 272(-30,+31) keV (chi2 = 84/77 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/38398. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36390] LIGO/Virgo/KAGRA S241130n: Updated Sky localization
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38397 SUBJECT: LIGO/Virgo/KAGRA S241130n: Updated Sky localization DATE: 24/11/30 20:02:05 GMT FROM: Elise Sänger at Max Planck Institute for Gravitational Physics (AEI Potsdam) <elise.sanger(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 S241130n (GCN Circular 38391). 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/S241130n For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 302 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1790 +/- 518 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/38397. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36389] LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38396 SUBJECT: LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits DATE: 24/11/30 17:57:41 GMT FROM: Dalya Akl at American Uni. SHJ <dalyaakl.d(a)gmail.com> D. Akl (AUS), C. Andrade (UMN), E. de Bruin (UMN), M. Tanasan (NARIT), N. Kochiashvili (AbAO), T. Hussenot-Desenonges (IJCLAB), M. Coughlin (UMN), M. Molham (NRIAG), S. Agayeva (Shamakhy Obs.), S. Antier (OCA), S. Karpov (FZU), D. Turpin (CEA-Saclay/Irfu), I. Tosta e Melo (UniCT-DFA), P. Hello (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), M. Masek (FZU), K. Noysena (NARIT), M. Eldepsy (NRIAG), A. Shokry (NRIAG), E. Elhosseiny (NRIAG), A. Takey (NRIAG) on behalf of the GRANDMA collaboration: We observed the field of the Swift/BAT-GUANO candidate counterpart (DeLaunay et al., GCN 38308) of the GW compact binary merger candidate S241125n (LIGO/Virgo/KAGRA Collaborations, GCN 38305) with the GRANDMA network. Our observations were conducted with the FRAM-CTA-N, TRT-SRO, and KAO telescopes starting ~0.8 days post T0 in the R, I, and i' bands, respectively. No clear candidate is identified within the 5 arcmin uncertainty region around the BAT position (RA, Dec = 58.079, 69.689 deg), with the following 5-sigma upperlimits: +---------------------+-------------+--------+----------+------------+ | T-mid(UTC) | Exposure(s) | Filter | U.L.(AB) | Instrument | +=====================+=============+========+==========+============+ | 2024-11-25T20:32:50 | 20x120 | R | 16.38 | FRAM-CTA-N | | 2024-11-25T23:38:47 | 23x150 | i' | 21.87 | KAO | | 2024-11-27T07:30:28 | 6x300 | I | 19.83 | TRT-SRO | | 2024-11-28T02:35:43 | 8x300 | I | 20.22 | TRT-SRO | +---------------------+-------------+--------+----------+------------+ This non-detection is consistent with Chen et al., GCN 38314, Watson et al., GCN 38317, Swain et al., GCN 38322, Mohan et al., GCN 38325, Jiang et al., GCN 38328, Becerra et al., GCN 38329. Our FRAM-CTA-N observation includes the positions of all 5 Swift-XRT X-ray sources (Page et al., GCN 38324). The KAO and TRT-SRO observations include only the position of the S241125n_X3 XRT source. We do not detect any clear candidates within the localization regions of these sources. This non-detection is consistent with Becerra et al., GCN 38329 and Akl et al., GCN 38334. Further, the FRAM-CTA-N observation includes all of the X-ray sources detected by EP-FXT (Wang et al., GCN 38345), while the KAO and TRT-SRO images include only the X-ray source detected by both modules of the EP-FXT with an averaged position at RA, Dec = 58.1097, 69.6392 deg and an uncertainty of 10 arcsec. We do not detect any of the EP-FXT sources across all of our images. All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). Images obtained in Johnson Cousin filters were calibrated using the Gaia DR3 Synphot catalog, while images taken with Sloan filters were calibrated using the Pan-STARRS DR1 catalog. We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023). GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). View this GCN Circular online at https://gcn.nasa.gov/circulars/38396. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36388] GRB 241128A: AbAO optical upper limit
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38395 SUBJECT: GRB 241128A: AbAO optical upper limit DATE: 24/11/30 15:48:32 GMT FROM: Alexei Pozanenko at IKI, Moscow <grb.alex(a)gmail.com> N. Pankov (HSE), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova (IKI), S. Belkin (HSE, Monash) report on behalf of GRB IKI FuN: We observed the field of GRB 241128A (Brivio et al., GCN 38367; Page, GCN 38368; Parsotan et al., GCN 38387) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter on 2024-11-29 starting (UT) 14:47:06. We do not detect the afterglow (Hu et al., GCN 38371; Izzo and Malesani, GCN 38372; Gompertz et al., GCN 38373; Akl et al., GCN 38382; Pankov et al., GCN 38383). Preliminary photometry of the field is the following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2024-11-29 14:47:06 0.96877 85x60 R n/d n/d 20.2 The photometry is based on nearby USNO-B1.0 R2 star View this GCN Circular online at https://gcn.nasa.gov/circulars/38395. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36387] LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38394 SUBJECT: LIGO/Virgo/KAGRA S241127aj: Updated Sky localization DATE: 24/11/30 14:56:01 GMT FROM: ethan.payne(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted additional 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 S241127aj (GCN Circular 38361). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline1.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S241127aj For the Bilby.offline1.multiorder.fits,0 sky map, the 90% credible region is 53 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1050 +/- 67 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/38394. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36386] LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38393 SUBJECT: LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate DATE: 24/11/30 11:55:12 GMT FROM: martina.dicesare(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241130be during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-11-30 11:04:22.113 UTC (GPS time: 1416999880.113). The candidate was found by the GstLAL [1], MBTA [2], PyCBC Live [3], and SPIIR [4] analysis pipelines. S241130be is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.9e-10 Hz, or about one in 1e2 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241130be The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), or NSBH (<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 4%. 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 [6], distributed via GCN notice about 28 seconds after the candidate event time. * bayestar.multiorder.fits,1, 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,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 1301 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1350 +/- 388 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] Chu et al. PRD 105, 024023 (2022) doi:10.1103/PhysRevD.105.024023 [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/38393. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36385] LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38392 SUBJECT: LIGO/Virgo/KAGRA S241129aa: Updated Sky localization DATE: 24/11/30 06:40:27 GMT FROM: ethan.payne(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 S241129aa (GCN Circular 38377). 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/S241129aa For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 269 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2499 +/- 437 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/38392. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36384] LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38391 SUBJECT: LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate DATE: 24/11/30 05:06:18 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241130n during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-11-30 03:49:08.603 UTC (GPS time: 1416973766.603). The candidate was found by the cWB [1], cWB BBH [2], GstLAL [3], MBTA [4], PyCBC Live [5], and SPIIR [6] analysis pipelines. S241130n is an event of interest because its false alarm rate, as estimated by the online analysis, is 4e-20 Hz, or about one in 1e12 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241130n The classification of the GW signal, in order of descending probability, is BBH (>99%), BNS (<1%), NSBH (<1%), or Terrestrial (<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%. [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 29 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 543 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2052 +/- 550 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] Chu et al. PRD 105, 024023 (2022) doi:10.1103/PhysRevD.105.024023 [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/38391. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36383] SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38390 SUBJECT: SVOM/GRM observation of a short burst from soft gamma repeater Kes 73 DATE: 24/11/30 02:41:15 GMT FROM: Wang-Chen Xue <wcxuemail(a)gmail.com> SVOM/GRM team: Wang-Chen Xue, 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, 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, SVOM/GRM was triggered in-flight by a short burst (SVOM trigger reference: sb24112902) from Kes 73 at 2024-11-29T10:56:49.200 UTC (T0), which was also observed by Fermi/GBM and Swift/BAT (Atel #16927). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of single pulse with a duration of about 0.1 s. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb241129B.png 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/GRM point of contact for this burst is: Wang-Chen Xue (IHEP)(xuewc(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38390. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36382] GRB 241128C: SVOM/GRM observation
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38389 SUBJECT: GRB 241128C: SVOM/GRM observation DATE: 24/11/30 02:39:57 GMT FROM: Wang-Chen Xue <wcxuemail(a)gmail.com> SVOM/GRM team: Wang-Chen Xue, 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, 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, SVOM/GRM was triggered in-flight by a short burst (SVOM trigger reference: sb24112802) at 2024-11-28T18:07:23.050 UTC (T0). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of single pulse with a duration of about 0.3 s. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb241128C.png 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/GRM point of contact for this burst is: Wang-Chen Xue (IHEP)(xuewc(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38389. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36381] GRB 241128B: SVOM/GRM observation
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38388 SUBJECT: GRB 241128B: SVOM/GRM observation DATE: 24/11/30 02:39:10 GMT FROM: Wang-Chen Xue <wcxuemail(a)gmail.com> SVOM/GRM team: Wang-Chen Xue, 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, 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, SVOM/GRM was triggered in-flight by a short burst (SVOM trigger reference: sb24112801) at 2024-11-28T05:22:24.000 UTC (T0). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a duration of about 10 s. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb241128B.png 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/GRM point of contact for this burst is: Wang-Chen Xue (IHEP)(xuewc(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38388. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36380] GRB 241128A: Swift-BAT refined analysis
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38387 SUBJECT: GRB 241128A: Swift-BAT refined analysis DATE: 24/11/30 02:20:35 GMT FROM: Amy <yarleen(a)gmail.com> T. Parsotan (GSFC), S. D. Barthelmy (GSFC), R. Brivio (INAF-OAB), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+899 sec from the recent telemetry downlink, we report further analysis of BAT GRB 241128A (trigger #1270999) (Brivio et al., GCN Circ. 38367). The BAT ground-calculated position is RA, Dec = 273.724, 33.492 deg which is RA(J2000) = 18h 14m 53.7s Dec(J2000) = +33d 29' 32.9" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 52%. The mask-weighted light curve shows a multi-pulse structure that starts at ~T0 and ends at ~T+240 s. The main pulse starts at ~T0, peaks at ~T+3 s, and ends at ~T+10 s. In addition, there is a weak pulse at ~T+220 s. T90 (15-350 keV) is 238.32 +- 15.83 sec (estimated error including systematics). The time-averaged spectrum from T-0.86 to T+244.08 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.54 +- 0.31. The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+2.88 sec in the 15-150 keV band is 1.0 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1270999 View this GCN Circular online at https://gcn.nasa.gov/circulars/38387. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36379] GRB 241127A: Swift-BAT refined analysis
by GCN Circulars 30 Nov '24

30 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38386 SUBJECT: GRB 241127A: Swift-BAT refined analysis DATE: 24/11/30 02:05:21 GMT FROM: Amy <yarleen(a)gmail.com> D. M. Palmer (LANL), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), C. Salvaggio (INAF-OAB), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-50 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 241127A (trigger #1270788) (Salvaggio et al., GCN Circ. 38354). The BAT ground-calculated position is RA, Dec = 327.911, -56.652 deg which is RA(J2000) = 21h 51m 38.5s Dec(J2000) = -56d 39' 08.1" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows some weak emission that starts at ~T-21 s, followed by the main pulse that starts at ~T-1 s, peaks at ~T+1 s, and ends at ~T+9 s. T90 (15-350 keV) is 26.02 +- 3.63 sec (estimated error including systematics). The time-averaged spectrum from T-20.83 to T+9.13 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.10 +- 1.01, and Epeak of 19.0 +- 12.56 keV (chi squared 52.96 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 6.5 +- 0.8 x 10^-07 erg/cm2 and the 1-sec peak flux measured from T+0.09 sec in the 15-150 keV band is 2.3 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.65 +- 0.21 (chi squared 60.15 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1270788 View this GCN Circular online at https://gcn.nasa.gov/circulars/38386. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36378] EP241126a: NOT optical observations
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38385 SUBJECT: EP241126a: NOT optical observations DATE: 24/11/29 22:23:22 GMT FROM: Daniele B. Malesani at IMAPP / Radboud University <d.malesani(a)astro.ru.nl> Daniele B. Malesani (DAWN/NBI and Radboud Univ.), Peter G. Jonker (Radboud Univ.), Franz E. Bauer (PUC), Maria E. Ravasio (Radboud Univ.), Jonathan Quirola-Vasquez (Radboud Univ.), Javi Sanchez-Sierras (Radboud Univ.), Andrew J. Levan (Radboud Univ. and Warwick Univ.), on behalf of a larger collaboration, and Jacco H. Terwel (NOT and TCD), report: We observed the optical counterpart (Fu et al., GCN 38337; Li et al., GCN 38338; Geng et al., GCN 38357; Qiu et al., GCN 38378) of the X-ray transient EP241126a (Hu et al., GCN 38335; Zheng et al., GCN 38339), using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations were carried out in the SDSS r band and were unfortunately affected by "non-ideal" seeing (>2.5"). The mean time of our observation was 2024 Nov 27.836 UT, that is 24.4 hr after the EP trigger, and the total exposure time was 9x240 s. The optical counterpart is marginally detected in our stacked image, with a magnitude r = 23.4 +- 0.3 (AB, calibrated against nearby sources from the Pan-STARRS catalog). View this GCN Circular online at https://gcn.nasa.gov/circulars/38385. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36377] GRB 241127A: PRIME near-infrared detection
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38384 SUBJECT: GRB 241127A: PRIME near-infrared detection DATE: 24/11/29 19:31:33 GMT FROM: Joe Durbak at UMD <gcn.joedurbak(a)gmail.com> J. Durbak (UMD), E. Troja (U Rome), O. Guiffreda (UMD), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC) Following the Swift BAT detection (GCN 38354), we observed the transient field in J and H filters with PRIME ~23 hours after Swift detection. At the position of the optical counterpart reported by Swift UVOT (GCN 38354), we detect an uncatalogued source in J-band. Using nearby VISTA Hemispherical Survey (VHS) for preliminary calibration we derive the following magnitude and limit, not corrected for Galactic extinction: | Filter | Mag(AB) | |--------|--------------| | J | 20.5 +/- 0.1 | | H | > 20.1 | 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/38384. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36376] GRB 241127A: PRIME near-infrared detection
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38384 SUBJECT: GRB 241127A: PRIME near-infrared detection DATE: 24/11/29 19:31:33 GMT FROM: Joe Durbak at UMD <gcn.joedurbak(a)gmail.com> J. Durbak (UMD), E. Troja (U Rome), O. Guiffreda (UMD), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC) Following the Swift BAT detection (GCN 38354), we observed the transient field in J and H filters with PRIME ~23 hours after Swift detection. At the position of the optical counterpart reported by Swift UVOT (GCN 38354), we detect an uncatalogued source in J-band. Using nearby VISTA Hemispherical Survey (VHS) for preliminary calibration we derive the following magnitude and limit, not corrected for Galactic extinction: | Filter | Mag(AB) | |--------|--------------| | J | 20.5 +/- 0.1 | | H | > 20.1 | 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/38384. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36375] GRB 241128A: Mondy optical observations
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38383 SUBJECT: GRB 241128A: Mondy optical observations DATE: 24/11/29 16:03:19 GMT FROM: XXXX at IKI <alex(a)cgrsmx.iki.rssi.ru> N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova (IKI) report on behalf of GRB IKI FuN: We observed the field of GRB 241128A (Brivio et al., GCN 38367; Page, GCN 38368) with AZT-33IK telescope of Mondy observatory in R-filter on 2024-11-29 starting (UT) 10:48:37. We detect the afterglow (Hu et al., GCN 38371; Izzo and Malesani, GCN 38372; Gompertz et al., GCN 38373; Akl et al., GCN 38382). Preliminary photometry of the afterglow is the following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2024-11-29 10:48:37 0.79796 15x120 R 19.80 0.10 22.9 The photometry is based on nearby USNO-B1.0 R2 stars. View this GCN Circular online at https://gcn.nasa.gov/circulars/38383. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36374] GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38382 SUBJECT: GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits DATE: 24/11/29 15:25:01 GMT FROM: Dalya Akl at American Uni. SHJ <dalyaakl.d(a)gmail.com> D. Akl (AUS), E. de Bruin (UMN), C. Andrade (UMN), M. Tanasan (NARIT), N. Kochiashvili (AbAO), T. Hussenot-Desenonges (IJCLAB), M. Coughlin (UMN), M. Molham (NRIAG), S. Agayeva (Shamakhy Obs.), S. Antier (OCA), S. Karpov (FZU), D. Turpin (CEA-Saclay/Irfu), I. Tosta e Melo (UniCT-DFA), P. Hello (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), M. Masek (FZU), A. Klotz (IRAP), M. Boer, S. Gervasoni, C. Limonta (OCA), E. Broens, F. Kugel (KNC), on behalf of the GRANDMA and Kilonova-Catcher collaborations: We observed the field of GRB 241128A (Brivio et al., GCN 38367) detected by Swift-BAT with GRANDMA and its citizen science project Kilonova-catcher (KNC). Our observations were performed with the FRAM-Auger, TAROT-TCA, KNC T400, and KNC-T-BRO telescopes starting from TGRB+108 min. We clearly detect the optical afterglow within the Swift-XRT uncertainty region (Beardmore et al., GCN 38374) and obtain the following magnitudes and 5-sigma upperlimits: +---------------------+-------------+--------+----------------+------------+ | T-mid(UTC) | Exposure(s) | Filter | Mag (AB) | Instrument | +=====================+=============+========+================+============+ | 2024-11-28T18:02:48 | 27x60 | Clear | 19.50 +/- 0.07 | KNC | | 2024-11-28T18:11:15 | 7x180 | Clear | 19.78 +/- 0.22 | KNC | | 2024-11-28T18:38:26 | 11x180 | Clear | 19.67 +/- 0.19 | KNC | | 2024-11-28T19:31:58 | 18x120 | R | 17.84 (U.L.) | FRAM-Auger | | 2024-11-28T19:40:56 | 3x180 | Clear | 17.53 (U.L.) | TAROT-TCA | +---------------------+-------------+--------+----------------+------------+ Our detection is consistent with the optical afterglow detected and reported by Hu et al., GCN 38371. Further, our magnitudes are consistent with those reported by LCO (Izzo and Malesani, GCN 38372) and NOT (Gompertz et al., GCN 38373). All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). Images obtained in Johnson Cousin filters were calibrated using the Gaia DR3 Synphot catalog, while images taken with a clear filter were calibrated using the Gaia eDR3 Catalog. We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023). GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/). View this GCN Circular online at https://gcn.nasa.gov/circulars/38382. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36373] Swift-XRT observations of IceCube -241127A
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38381 SUBJECT: Swift-XRT observations of IceCube -241127A DATE: 24/11/29 14:11:26 GMT FROM: P.A. Evans at U. Leicester <pae9(a)leicester.ac.uk> P.A. Evans (U. Leicester) and J.A. Kennea (PSU) report on behalf of the Swift-XRT team, Swift-XRT observed the field of IceCube-241127A (IceCube Collaboration, GCN 38349) between 18:51 and 22:12 UT on 2024 November 27 (16.8 to 29.4 ks after the trigger), gathering 4.7 ks over 10 pointings centred on the neutrino position. One X-ray source is detected at a RA, Dec = 164.0502° 5.2615, which is equivalent to: RA (J2000) = 10h 56m 12.04s Dec (J2000) = +05d 15’ 41.3S" with an uncertainty of 8.4 arcseconds (radius, 90 confidence). This is consistent with the a known X-ray source from the Swift [LSXPS](https://www.swift.ac.uk/LSXPS/) catalogue: [LSXPS J105612.0+051546](https://www.swift.ac.uk/LSXPS/LSXPS%20J105612.0%2B051546); and the optical galaxy SDSS J105612.22+051544.6. The count-rate in the historical Swift data is 0.023 (+0.007, -0.006) ct/sec; in the new observations the count-rate is 0.015 (+0.006, -0.005); i.e. the source shows no signs of outburst. Three other objects were found, all of which are rated “poor” by the detection algorithm which corresponds to a ~1 sigma detection, their details are below (all positions in J2000, errors are arcseconds, 90% confidence). SWIFT J105542.0+051112 (source 2): RA: 10h 55m 42.04s (= 163.9252) Dec: +05d 11’ 12.1" (= +5.1867) Error: 7.0 This source is 2.1 arcseconds from the radio source NVSS J105542+051112. SWIFT J105615.1+051437 (source 3): RA: 10h 56m 15.13s (= 164.0630) Dec: +05d 14’ 37.7" (= +5.2438) Error: 8.2 SWIFT J105711.6+054504 (source 4): RA (J2000): 10h 57m 11.64s (= 164.2985) Dec (J2000): +05d 45’ 04.8" (= +5.7513) Error: 7.6 This source is 10.6 arseconds from the high proper-motion star PM J10571+0544A, and 13arcseconds from the Rosat source: 1RXS J105710.9+054458. The Rosat brightness is equivalent to 0.048 +/- 0.011 ct/sec in XRT (assuming a power-law spectrum, photon index 1.7, nH = 3e20 cm^-2); the XRT count-rate is 0.013 (+0.008, -0.006); this this possible source also shows no evidence for an outburst. The full XRT analysis can be viewed online at https://www.swift.ac.uk/neutrino/NEUTRINO_FIELD00042/. View this GCN Circular online at https://gcn.nasa.gov/circulars/38381. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36372] Swift GRB 241128A: Global MASTER-Net observations report
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38380 SUBJECT: Swift GRB 241128A: Global MASTER-Net observations report DATE: 24/11/29 10:38:36 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) was pointed to the Swift GRB 241128A ( R. Brivio et al., GCN 38367) errorbox 65606 sec after notice time and 65649 sec after trigger time at 2024-11-29 10:28:43 UT, with upper limit up to 19.3 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -12.6 deg. The galactic latitude b = 21 deg., longitude l = 61 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2687409 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 65694 | MASTER-Tunka | C | 90 | 19.1 | 65798 | MASTER-Tunka | C | 90 | 19.2 | 65887 | MASTER-Tunka | C | 60 | 19.3 | 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/38380. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36371] Fermi-LAT gamma-ray observations of IceCube-241127A
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38379 SUBJECT: Fermi-LAT gamma-ray observations of IceCube-241127A DATE: 24/11/29 10:03:28 GMT FROM: Leo Pfeiffer at University of Würzburg <pfeiffer.leo(a)gmail.com> L. Pfeiffer (Univ. of Wuerzburg), S. Buson (DESY, Univ. of Wuerzburg), C. Bartolini (INFN Bari), S. Garrappa (Weizmann Institute of Science) 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 IC241127A neutrino event (GCN 38349) 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 2024-11-27 14:11:14.42 UTC (T0) with J2000 position RA = 164.09 (+0.46, -0.52) deg, Decl. = 5.38 (+0.58, -0.55) deg 90% PSF containment. No cataloged gamma-ray sources are found within the 90% IC241127A localization error (The Fourth Fermi-LAT catalog, 4FGL-DR4, The Fermi-LAT collaboration 2023, arXiv:2307.12546). 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 IC241127A 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 <3.09e-10 ph cm^-2 s^-1 for ~16-years (2008-08-04 / T0), <1.67e-08(<9.31e-08) ph cm^-2 s^-1 for a 1-month (1-day) 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 L. Pfeiffer (leonard.pfeiffer at stud-mail.uni-wuerzburg.de). 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/38379. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36370] EP241126a: SVOM/VT observations
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38378 SUBJECT: EP241126a: SVOM/VT observations DATE: 24/11/29 03:41:17 GMT FROM: Huali Li at at NAOC, SVOM <lhl(a)nao.cas.cn> SVOM/VT commissioning team: Y. L. Qiu, L. P. Xin, C. Wu, H. L. Li, 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), L. Zhang (IHEP), Y.D. Hu(GXU), X.L. Chen (YNU), K. Chatterjee (YNU) 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 fast X-ray transient EP241126a (EP-WXT，Hu et al., GCN 38335；EP-FXT，Zheng et al., GCN 38339; SVOM/GRM, Zheng et al., GCN 38342) in ToO mode from 2024-11-28T02:02:37.5 UT, about 30.38 hours after the burst. The VT conducted observations in VT_B band (400-650nm) and VT_R band (650-1000nm) simultaneously. The optical counterpart (TRT, Fu et al., GCN 38337; GSP, Li et al., GCN 38338; WFST, Geng et al, GCN 38357) was detected in VT_R combined image with the brightness of 22.95 +/- 0.15 mag at the midtime of 33.27 hours after the burst. It was not detected in VT_B combined image, with the 3 sigma limit magnitudes of VT_B~24.1 mag. The exposure time of images in VT_R and VT_B are 5670 sec and 5760 sec respectively. 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/38378. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36369] LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38377 SUBJECT: LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate DATE: 24/11/29 03:05:20 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241129aa during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-11-29 02:18:32.610 UTC (GPS time: 1416881930.610). The candidate was found by the cWB [1], cWB BBH [2], GstLAL [3], MBTA [4], PyCBC Live [5], and SPIIR [6] analysis pipelines. S241129aa is an event of interest because its false alarm rate, as estimated by the online analysis, is 4e-20 Hz, or about one in 1e12 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241129aa The classification of the GW signal, in order of descending probability, is BBH (>99%), BNS (<1%), NSBH (<1%), or Terrestrial (<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%. [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,1, an initial localization generated by BAYESTAR [8], distributed via GCN notice about 34 seconds after the candidate event time. * bayestar.multiorder.fits,2, 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,2. For the bayestar.multiorder.fits,2 sky map, the 90% credible region is 502 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2287 +/- 548 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] Chu et al. PRD 105, 024023 (2022) doi:10.1103/PhysRevD.105.024023 [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/38377. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36368] GRB 241128A: Swift-XRT refined Analysis
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38376 SUBJECT: GRB 241128A: Swift-XRT refined Analysis DATE: 24/11/29 01:47:12 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.A. Kennea (PSU), D.N. Burrows (PSU), M. A. Williams (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 241128A, from 3.9 ks to 28.3 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The light curve can be modelled with a power-law decay with a decay index of alpha=0.51 (+/-0.15). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.07 (+0.31, -0.25). The best-fitting absorption column is 8.9 (+7.5, -2.9) x 10^20 cm^-2, consistent with the Galactic value of 6.0 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.2 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 8.9 (+7.5, -2.9) x 10^20 cm^-2 Galactic foreground: 6.0 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 2.07 (+0.31, -0.25) If the light curve continues to decay with a power-law decay index of 0.51, the count rate at T+24 hours will be 0.017 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.6 x 10^-13 (6.9 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01270999. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38376. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36367] GRB 241129A: Fermi GBM Final Real-time Localization
by GCN Circulars 29 Nov '24

29 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38375 SUBJECT: GRB 241129A: Fermi GBM Final Real-time Localization DATE: 24/11/29 01:42:13 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 01:31:33 UT on 29 Nov 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241129A (trigger 754536698.4246 / 241129064). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 245.5, Dec = 1.1 (J2000 degrees, equivalent to J2000 16h 22m, 1d 06'), with a statistical uncertainty of 5.0 degrees. The angle from the Fermi LAT boresight is 75.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241129064/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241129064/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241129064/… View this GCN Circular online at https://gcn.nasa.gov/circulars/38375. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36366] GRB 241128A: Enhanced Swift-XRT position
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38374 SUBJECT: GRB 241128A: Enhanced Swift-XRT position DATE: 24/11/28 23:56:21 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 1910 s of XRT Photon Counting mode data and 3 UVOT images for GRB 241128A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 273.72356, +33.43915 which is equivalent to: RA (J2000): 18h 14m 53.65s Dec (J2000): +33d 26' 20.9" with an uncertainty of 3.0 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38374. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36365] GRB 241128A: NOT optical observations
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38373 SUBJECT: GRB 241128A: NOT optical observations DATE: 24/11/28 22:59:25 GMT FROM: Daniele B. Malesani at IMAPP / Radboud University <d.malesani(a)astro.ru.nl> B. Gompertz (Birmingham), D. B. Malesani (DAWN/NBI and Radboud Univ.), L. Izzo (INAF/OACN, DARK/NBI), J. H. Terwel (NOT and TCD) report on behalf of a larger collaboration: We observed the field of GRB 241128A (Brivio et al., GCN 38367; Page, GCN 38368) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations were carried out at large airmass and under a poor seeing of 2.5". A total of 3x300 s and 5x200 s were secured in the SDSS r and z bands, respectively. From a preliminary reduction of the data, the optical afterglow (Hu et al., GCN 38371; Izzo & Malesani, GCN 38372) is well detected in our images. We measure r = 19.52 +- 0.03 AB on Nov 28.80 UT (2.95 hr after the GRB); z = 19.03 +- 0.05 AB on Nov 28.81 UT (3.25 hr after the GRB). Both magnitudes are calibrated against nearby objects from the Pan-STARRS catalog. We note a discrepancy in the r-band magnitude compared to the nearly simultaneous measurement by Izzo & Malesani (GCN 38372), which we are unable to account for at the present time. View this GCN Circular online at https://gcn.nasa.gov/circulars/38373. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36364] GRB 241128A: LCO optical detection
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38372 SUBJECT: GRB 241128A: LCO optical detection DATE: 24/11/28 21:48:43 GMT FROM: luca.izzo(a)inaf.it L. Izzo (INAF-OACn and DARK/NBI), and D. B. Malesani (DAWN/NBI and Radboud Univ.) report: We observed the field of GRB 241128A (Brivio et al., GCN #38367) with the Sinistro instrument mounted on the 1-m telescope of the LCO network, located at the Teide Observatory, Spain. Observations started on 2024 November 28 at 19:04 UT (2.83 hr after the GRB trigger). We obtained a series of 3x300 s images in the SDSS-r filter. The afterglow reported by Hu et al. (GCN #38371; see also Page et al., GCN #38368) is well detected in our images. We measure a preliminary magnitude of r = 19.24 +/- 0.07 mag (AB), calibrated against nearby stars from the Pan-STARRS catalog. This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 101004719. View this GCN Circular online at https://gcn.nasa.gov/circulars/38372. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36363] GRB 241128A: 1.5m OSN optical afterglow detection
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38371 SUBJECT: GRB 241128A: 1.5m OSN optical afterglow detection DATE: 24/11/28 21:15:38 GMT FROM: Youdong HU at INAF-OAB <huyoudong072(a)hotmail.com> Y.-D. Hu (INAF-OAB), V. Casanova, E. Fernandez-Garcia, A. J. Castro-Tirado, S.-Y. Wu, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC) and G. Garcia-Segura (UNAM), on behalf of a larger collaboration, report: Following the detection of GRB 241128A by Swift (Brivio et al. GCN 38367), we triggered the 1.5m OSN telescope in Granada (Spain) starting on Nov 28, 18:19 UT (~2.1 hrs post burst) in R & I-bands. An uncatalogued object is detected within the XRT error circle (Page et al. GCNC 38368) with R=19.3+-0.1 mag, at coordinates RA(J2000) = 18:14:53.55, DEC(J2000) = +33:26:20.32, which we proposed as the GRB 241128A optical afterglow. Spectroscopic observations are encouraged. We thank the staff at OSN for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38371. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36362] LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38370 SUBJECT: LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations DATE: 24/11/28 19:18:52 GMT FROM: Thomas Hussenot-Desenonges at IJCLab <thomas.hussenot(a)ijclab.in2p3.fr> T. Hussenot-Desenonges (IJCLAB), D. Akl (AUS), M. Coughlin (UMN), M. Molham (NRIAG), S. Agayeva (Shamakhy Obs.), S. Antier (OCA), C. Andrade (UMN), S. Karpov (FZU), I. Tosta e Melo (UniCT-DFA), P. Hello (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), M. Masek (FZU), on behalf of the GRANDMA collaboration: We performed tiled observations of the LIGO/VIRGO event S241127aj (GCN 38336) with the 25 cm f/6.3 FRAM-CTA-N telescope located at Observatorio del Roque de los Muchachos, La Palma, Spain. Observations were conducted from 2024-11-28T06:05:22 to 2024-11-28T08:21:54, 1.0 day after the GW trigger time. We obtained a total of 23 images in the Johnson R band, acquiring 2 consecutive 2-minute long exposures at the individual pointings in the table below, for a total of 2760 seconds. The observation plan was constructed to cover 11.8 degrees of the bayestar.multiorder.fits,1 localization, corresponding to ~3.1% of the enclosed probability. The regions of highest localization probability were unfortunately unobservable because of constraints of proximity to the Sun. Our low latency analysis (Karpov et al. 2021) did not reveal any significant candidate down to the limits listed in the table below (5 sigma, Vega system): | Start time (UTC) | RA | DEC | Lim.Mag. | Exposure (seconds) | 2024-11-28T06:05:22.573 | 189.11392 | -31.62162 | 17.04 | 120 | 2024-11-28T06:07:34.140 | 189.11392 | -31.62162 | 17.03 | 120 | 2024-11-28T06:09:56.133 | 188.46395 | -30.64865 | 16.96 | 120 | 2024-11-28T06:12:07.703 | 188.46395 | -30.64865 | 17.02 | 120 | 2024-11-28T06:14:26.822 | 187.97468 | -31.62162 | 17.19 | 120 | 2024-11-28T06:16:38.420 | 187.97468 | -31.62162 | 17.13 | 120 | 2024-11-28T06:19:00.368 | 189.66443 | -36.48649 | 17.45 | 120 | 2024-11-28T06:21:11.958 | 189.66443 | -36.48649 | 17.46 | 120 | 2024-11-28T06:23:43.572 | 195.42857 | -73.45946 | 17.74 | 120 | 2024-11-28T06:25:55.193 | 195.42857 | -73.45946 | 17.76 | 120 | 2024-11-28T06:28:16.041 | 198.85714 | -73.45946 | 17.73 | 120 | 2024-11-28T06:30:27.649 | 198.85714 | -73.45946 | 17.73 | 120 | 2024-11-28T06:32:48.431 | 192 | -73.45946 | 17.76 | 120 | 2024-11-28T07:11:24.897 | 188.9441 | -29.67568 | 17.72 | 120 | 2024-11-28T07:13:36.499 | 188.9441 | -29.67568 | 17.65 | 120 | 2024-11-28T07:15:56.104 | 189.59248 | -30.64865 | 17.67 | 120 | 2024-11-28T07:18:07.696 | 189.59248 | -30.64865 | 17.53 | 120 | 2024-11-28T07:20:31.567 | 190.25316 | -31.62162 | 17.57 | 120 | 2024-11-28T07:22:43.183 | 190.25316 | -31.62162 | 17.53 | 120 | 2024-11-28T07:25:14.770 | 192 | -73.45946 | 17.64 | 120 | 2024-11-28T07:27:26.342 | 192 | -73.45946 | 17.65 | 120 | 2024-11-28T08:17:43.339 | 188.45638 | -36.48649 | 16.07 | 120 | 2024-11-28T08:19:54.951 | 188.45638 | -36.48649 | 15.87 | 120 All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022), and calibrated using the Gaia DR3 SynPhot catalogue. The data are not corrected from Galaxy extinction. We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023) GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). View this GCN Circular online at https://gcn.nasa.gov/circulars/38370. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36361] Fermi trigger No 754492985: Global MASTER-Net observations report
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38369 SUBJECT: Fermi trigger No 754492985: Global MASTER-Net observations report DATE: 24/11/28 19:01:02 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB241128.56 (trigger No 754492985,20h 05m 12.00s , -50d 37m 01.2s, R=32.43) errorbox 18760 sec after notice time and 18796 sec after trigger time at 2024-11-28 18:36:17 UT, with upper limit up to 19.6 mag. Observations started at twilight. The observations began at zenith distance = 37 deg. The sun altitude is -13.3 deg. The galactic latitude b = -33 deg., longitude l = 348 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2687320 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 18886 | 2024-11-28 18:36:17 | MASTER-SAAO | (21h 51m 11.04s , -56d 55m 07.0s) | C | 180 | 19.3 | 19086 | 2024-11-28 18:39:36 | MASTER-SAAO | (21h 51m 14.31s , -56d 55m 53.2s) | C | 180 | 19.6 | 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/38369. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36360] GRB 241128A: Swift-XRT afterglow detection
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38368 SUBJECT: GRB 241128A: Swift-XRT afterglow detection DATE: 24/11/28 18:34:25 GMT FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk> K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team: Immediately following the BAT trigger on GRB 241128A, Swift entered the South Atlantic Anomaly, during which time no XRT data were taken. The field of the GRB became visible to the XRT at 17:16 UT, 3.9 ks after the trigger, at which point the XRT afterglow of the burst was detected at a position of RA, Dec = 273.72454, 33.43853 which is equivalent to: RA (J2000): 18:14:53.89 Dec(J2000): +33:26:18.9 with an uncertainty of 3.5 arcsec (radius, 90% confidence). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38368. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36359] GRB 241128A: Swift detection of a burst
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38367 SUBJECT: GRB 241128A: Swift detection of a burst DATE: 24/11/28 16:37:44 GMT FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk> R. Brivio (INAF-OAB), M. Ferro (INAF-OAB), C. Gronwall (PSU), R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), K. L. Page (U Leicester), D. M. Palmer (LANL), C. Salvaggio (INAF-OAB) and T. Sbarrato (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team: At 16:14:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 241128A (trigger=1270999). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 273.724, +33.435 which is RA(J2000) = 18h 14m 54s Dec(J2000) = +33d 26' 07" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Although a telemetry gap prevented the download of a BAT lightcurve, the trigger duration of 4 s indicates that this is a long burst. The XRT began observing the field at 16:16:32.2 UT, 118.0 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart. There are no prompt UVOT data available at this time. Although this source has not been confirmed during the short XRT observation (truncated by entrance into the SAA) or by the non-availability of the BAT lightcurve, the strength of peak (8.4 sigma) in the BAT image indicates that this is an astrophysical source. Burst Advocate for this burst is R. Brivio (riccardo.brivio AT inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/) View this GCN Circular online at https://gcn.nasa.gov/circulars/38367. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36358] GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38366 SUBJECT: GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections DATE: 24/11/28 16:24:29 GMT FROM: Thomas Hussenot-Desenonges at IJCLab <thomas.hussenot(a)ijclab.in2p3.fr> T. Hussenot-Desenonges (IJCLAB), D. Akl (AUS), M. Coughlin (UMN), M. Molham (NRIAG), S. Agayeva (Shamakhy Obs.), S. Antier (OCA), C. Andrade (UMN), S. Karpov (FZU), I. Tosta e Melo (UniCT-DFA), P. Hello (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), M. Masek (FZU), A. Klotz (IRAP), D. Turpin (CEA-Saclay/Irfu), M. Freeberg (KNC), on behalf of the GRANDMA and Kilonova-Catcher collaborations: We observed the field of GRB 241127A, detected by SWIFT (GCN 38354) and SVOM (GCN 38363) with the GRANDMA network and its citizen science project Kilonova-catcher (KNC). Our observations were performed with the TAROT-TCH, FRAM-Auger and the KNC-CHI-1, 60cm telescopes. We detect the afterglow already observed by Swift/XRT and UVOT (GCN 38354, 38362, 38364, 38365), MASTER (GCN 38353, 38358) and LCOGT (GCN 38359) and obtain the following magnitudes: | Tstart (UTC) | Telescope | Exposure | Filter | Magnitude | | 2024-11-28T00:33:05 | FRAM-Auger | 20x120s | R | 18.78 +- 0.20 (Vega)| | 2024-11-28T00:50:45 | TAROT-TCH | 4x180s | R | 19.14 +- 0.17 (Vega)| | 2024-11-28T01:16:26 | KNC-CHI-1 | 2x120s | r' | 19.4 +- 0.1 (AB) | | 2024-11-28T01:20:52 | KNC-CHI-1 | 2x120s | g' | 19.74 +- 0.09 (AB) | All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). TCH and KNC images were calibrated using the SkyMapper DR4 catalogue, the FRAM-Auger image used Gaia DR3 Synphot. The data are not corrected from Galaxy extinction. Our magnitudes are consistent with those reported by LCOGT in GCN 38359. We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023) A report of the observations of GRANDMA for this source can be seen at: https://skyportal-icare.ijclab.in2p3.fr/public/sources/GRB241127 GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/). View this GCN Circular online at https://gcn.nasa.gov/circulars/38366. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36357] GRB 241127A: Swift/UVOT Detection
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38365 SUBJECT: GRB 241127A: Swift/UVOT Detection DATE: 24/11/28 13:21:45 GMT FROM: Alice Breeveld at MSSL-UCL <a.breeveld(a)ucl.ac.uk> A. A. Breeveld (UCL-MSSL) and C. Salvaggio (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 241127A 484 s after the BAT trigger (Salvaggio et al., GCN Circ. 38354). The optical counterpart seen in the UVOT at the position given in that circular, and also reported by Ortega-Cass et al., (GCN Circ. 38359) and MASTER (Buckley et al., GCN circular 38352 and Francile et al., GCN circular 38358) is detected in all the filters used for the initial UVOT exposures and is fading. Preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 484 634 147 17.04 ± 0.03 white 16459 16862 393 19.81 +/1 0.09 b 15547 16453 885 20.3 ± 0.3 u 21787 22629 821 19.1 ± 0.1 v 10002 10870 847 19.7 ± 0.2 uvw1 20881 21780 886 19.5 ± 0.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.034 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/38365. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36356] GRB 241127A: Swift-XRT refined Analysis
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38364 SUBJECT: GRB 241127A: Swift-XRT refined Analysis DATE: 24/11/28 11:07:18 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> A. Melandri (INAF-OAR), S. Dichiara (PSU), J.A. Kennea (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 5.0 ks of XRT data for GRB 241127A, from 443 s to 27.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The light curve can be modelled with a power-law decay with a decay index of alpha=0.66 (+0.05, -0.06). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.97 (+0.18, -0.17). The best-fitting absorption column is 8.0 (+4.5, -3.9) x 10^20 cm^-2, in excess of the Galactic value of 2.7 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 8.0 (+4.5, -3.9) x 10^20 cm^-2 Galactic foreground: 2.7 x 10^20 cm^-2 Excess significance: 2.2 sigma Photon index: 1.97 (+0.18, -0.17) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01270788. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38364. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36355] GRB 241127A: SVOM/GRM observation
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38363 SUBJECT: GRB 241127A: SVOM/GRM observation DATE: 24/11/28 09:08:34 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, 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, SVOM/GRM detected GRB 241127A at 2024-11-27T21:43:16.230 UT (T0), which was also observed by Swift/BAT (C. Salvaggio, et al., GCN 38354). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of a single pulse with a duration of about 3 s. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb241127A.png This burst is located at about 75.6 degrees from the SVOM optical axis. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), the 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/GRM point of contact for this burst is: Chao Zheng (IHEP)(zhengchao97(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/38363. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36354] GRB 241127A: Enhanced Swift-XRT position
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38362 SUBJECT: GRB 241127A: Enhanced Swift-XRT position DATE: 24/11/28 07:55:25 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2379 s of XRT Photon Counting mode data and 9 UVOT images for GRB 241127A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 327.88543, -56.66544 which is equivalent to: RA (J2000): 21h 51m 32.50s Dec (J2000): -56d 39' 55.6" with an uncertainty of 2.1 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38362. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36353] LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38361 SUBJECT: LIGO/Virgo/KAGRA S241127aj: Updated Sky localization DATE: 24/11/28 05:18:19 GMT FROM: ethan.payne(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further offline 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 S241127aj (GCN Circular 38336). 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/S241127aj For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 105 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1100 +/- 99 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/38361. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36352] The EP-WXT trigger 01709125191 is not a real source
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38360 SUBJECT: The EP-WXT trigger 01709125191 is not a real source DATE: 24/11/28 04:19:36 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> B.-T. Wang (YNAO, CAS), T. C. Zheng (PMO, CAS), Y. L. Wang, S. X. Wen, W. X. Wang, W. Yuan (NAO, CAS) report on behalf of the Einstein Probe team: Further analysis of the late arrived telemetry data verifies that the EP-WXT on-board trigger 01709125191 at 2024-11-25T22:28:15.649 (UTC) is not a real source. View this GCN Circular online at https://gcn.nasa.gov/circulars/38360. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36351] GRB 241127A: LCOGT (40-cm) optical counterpart detection
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38359 SUBJECT: GRB 241127A: LCOGT (40-cm) optical counterpart detection DATE: 24/11/28 04:18:13 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf(a)iac.es> I. Ortega-Casas, B. Armas-Chinea, F. Dobrindt, P. Escudero-Coca, G. Fernández-Rodríguez, Á. García Lozano, A. Huertas Ferrer, C. Méndez-Lapido, M. Torreiro Martínez, G. Villa (all ULL), S.R. Berlanas (IAC and ULL), and I. Pérez-Fournon (IAC and ULL) We report on optical follow-up observations of GRB 241127A, detected by Swift BAT, XRT, and UVOT (Salvaglio et al., GCN circular 38354) and by MASTER (Buckley et al., GCN circular 38352 and Francile et al., GCN circular 38358). We observed the field of GRB 241127A with the two Las Cumbres Observatory Global telescope network (LCOGT) Planewave Delta Rho 350 telescopes, equipped with QHY600 CMOS detectors, located at the LCOGT node at the Cerro Tololo Inter-American Observatory (Chile) in the SDSS r', i', and g' filters, with 600 sec exposures in each of the filters. We detect the optical counterpart at a position consistent with the Swift UVOT (Salvaglio et al., GCN circular 38354) and MASTER (Buckley et al., GCN circular 38352 and Francile et al., GCN circular 38358) detections. We measure the following magnitudes, calibrated using stars from the catalog of Gaia DR3 synthetic photometry generated from the Gaia BP/RP mean spectra (Gaia collaboration 2022) and without corrections for Milky Way extinction: r' = 19.42 +/- 0.08, on 2024-11-28 00:58:30 UT, 3.25 hours after the Swift trigger i' = 19.27 +/- 0.15, on 2024-11-28 01:04:49 UT, 3.36 hours after the Swift trigger g' = 19.70 +/- 0.07, on 2024-11-28 01:10:03 UT, 3.45 hours after the Swift trigger In the Legacy Surveys DR10 catalog there is a faint galaxy close to the position of the GRB optical counterpart at RA, Dec (J2000, deg) = 327.8851, -56.6653 and with magnitudes g = 25.08, r = 24.70, i = 24.38, and z = 23.57, that is the likely GRB host galaxy. These results are based on observations made with the Las Cumbres Observatory’s education network telescopes that were upgraded through generous support from the Gordon and Betty Moore Foundation and are part of a course on Astrophysical Techniques of the Master in Astrophysics of the Universidad de La Laguna, Tenerife, Spain (LCOGT observing programme IAC2024B-010, ULL-ASTRO-MASTER). View this GCN Circular online at https://gcn.nasa.gov/circulars/38359. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36350] Swift GRB241127.91: Global MASTER-Net OT detection
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38358 SUBJECT: Swift GRB241127.91: Global MASTER-Net OT detection DATE: 24/11/28 03:15:55 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), 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 (Lomonosov MSU), O.Gress, N.Budnev(ISU), 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 GRB241127.91 9640 sec after notice time and 9658 sec after trigger time at 2024-11-28 00:24:14 UT. On our 9-th (60s exposure) set , obtained 10200 sec after tigger time at 2024-11-28 00:33:17 UT, we found 1 optical transient within Swift error-box (ra=327.921 dec=-56.685 r=0.05) brighter than 19.3. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 10230 2024-11-28 00:33:17 60 (21h 51m 32.32s , -56d 39m 56.5s) 19.4 The 5-sigma upper limit has been about 19.3mag The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38358. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36349] EP241126a: WFST Observations
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38357 SUBJECT: EP241126a: WFST Observations DATE: 24/11/28 02:53:42 GMT FROM: Tianrui Sun at Purple Mountain Obs,CAS <trsun(a)pmo.ac.cn> Jin-Jun Geng, Ji-An Jiang, Ning Jiang, Ming-Xin Wu, Min-Xuan Cai, Jia-Zheng Zhu, Kun Yan, Qing-Yi Hai, Xue-Feng Wu on behalf of the WFST Collaboration: Following the detection of the fast X-ray transient EP241126a by WXT (Hu et al., GCN 38335) and FXT on board Einstein Probe (Zheng et al., GCN 38339), TRT (Fu et al., GCN 38337) and GSP (Li et al., GCN 38338), we carried out image observations using the newly deployed Wide Field Survey Telescope (WFST Collaboration; arXiv:2306.07590) at Lenghu Astronomical Observation Base (Qinghai province, China) to search and follow up its afterglow in the error box. The optical counterpart candidate (Fu et al., GCN 38337 and Li et al., GCN 38338) was detected in the r band on the co-added images with an exposure time of 8 x 60s. Our preliminary results are as follows: |RA |DEC | DATE-OBS |Filter | Magnitude |02:14:57.974 |+11:42:05.34 |2024-11-27T11:47 |r | 22.55+/-0.23 We used the PanStarrs DR1 (Flewelling,2020) catalog as the magnitude reference for calibration. View this GCN Circular online at https://gcn.nasa.gov/circulars/38357. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36348] LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38356 SUBJECT: LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method DATE: 24/11/28 02:26:46 GMT FROM: Brandon Piotrzkowski <brandon.piotrzkowski(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration along with the Swift/BAT-GUANO Collaboration report: A search performed by the RAVEN pipeline [1] (reported in GCN Circular 38309) found a spatio-temporal coincidence between S241125n and a sub-threshold Swift/BAT trigger with ID 754189311 (DeLaunay et al., GCN Circular 38308). The estimated joint false alarm rate (FAR) for the spatial and temporal coincidence was reported to be 1.8e-11 Hz, or about one in 1e3 years (GCN 38315). See https://lscsoft.docs.ligo.org/raven/joint_far.html for a description of the Targeted Search joint FAR method. The difference between the joint FAR estimate in GCN 38315 and GCN 38308 can be accounted for by the updated gravitational-wave skymap, the use of the highest resolution information in the sky map combination, and by the fact that the GCN 38308 method included a correction for trials arising from multiple GW pipelines. The Targeted Search joint FAR presented above is dominated by the low FAR of the confident GW signal, which is much lower than the detected rate of BBH mergers. In this case of a confident GW signal, using a version of the Untargeted joint FAR method (see link above) is likely to more appropriately describe the background association rate. Using a conservative accounting of the BBH detection rate (1 per 3 days) along with the Untargeted joint FAR method increases the joint FAR to 1 per 6 years. [1] Urban, A. L. 2016, Ph.D. Thesis https://dc.uwm.edu/etd/1218 and Piotrzkowski, B. J. 2022, Ph.D. Thesis https://dc.uwm.edu/etd/3060 View this GCN Circular online at https://gcn.nasa.gov/circulars/38356. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36347] IceCube Alert 241127.59: Global MASTER-Net observations report
by GCN Circulars 28 Nov '24

28 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38355 SUBJECT: IceCube Alert 241127.59: Global MASTER-Net observations report DATE: 24/11/28 01:39:25 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the IceCube Alert 241127.59 (trigger No 41215060,10h 55m 02.88s , +05d 54m 46.8s, R=0.51) errorbox 39590 sec after notice time and 39645 sec after trigger time at 2024-11-28 01:11:59 UT, with upper limit up to 19.2 mag. The observations began at zenith distance = 65 deg. The sun altitude is -23.6 deg. The galactic latitude b = 55 deg., longitude l = 246 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2685949 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 39735 | 2024-11-28 01:11:59 | MASTER-SAAO | (10h 48m 19.09s , +05d 07m 06.3s) | C | 180 | 19.0 | 39934 | 2024-11-28 01:15:18 | MASTER-SAAO | (10h 56m 24.83s , +05d 08m 43.8s) | C | 180 | 19.2 | 40134 | 2024-11-28 01:18:38 | MASTER-SAAO | (11h 03m 32.09s , +05d 08m 51.5s) | C | 180 | 19.1 | 40915 | 2024-11-28 01:31:39 | MASTER-SAAO | (10h 48m 18.34s , +05d 06m 59.9s) | C | 180 | 17.7 | 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/38355. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36346] GRB 241127A: Swift detection of a burst with an optical counterpart
by GCN Circulars 27 Nov '24

27 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38354 SUBJECT: GRB 241127A: Swift detection of a burst with an optical counterpart DATE: 24/11/27 21:59:40 GMT FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk> C. Salvaggio (INAF-OAB), R. Brivio (INAF-OAB), S. Dichiara (PSU), M. Ferro (INAF-OAB), R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), A. Tohuvavohu (Caltech) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 21:43:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 241127A (trigger=1270788). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 327.922, -56.685 which is RA(J2000) = 21h 51m 41s Dec(J2000) = -56d 41' 06" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 10 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 21:44:22.8 UT, 66.6 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 327.88355, -56.66459 which is equivalent to: RA(J2000) = 21h 51m 32.05s Dec(J2000) = -56d 39' 52.5" with an uncertainty of 4.0 arcseconds (radius, 90% containment). This location is 105 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (2.68 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 6.1 (+6.36/-4.83) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 2.12e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 484 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 21:51:32.32 = 327.88467 DEC(J2000) = -56:39:55.1 = -56.66531 with a 90%-confidence error radius of about 0.61 arc sec. This position is 2.1 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.14 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.034. Burst Advocate for this burst is C. Salvaggio (chiara.salvaggio AT inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/) View this GCN Circular online at https://gcn.nasa.gov/circulars/38354. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36345] Swift GRB241127.91: Global MASTER-Net observations report
by GCN Circulars 27 Nov '24

27 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38353 SUBJECT: Swift GRB241127.91: Global MASTER-Net observations report DATE: 24/11/27 21:55:40 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB241127.91 (trigger No 1270788,21h 51m 41.28s , -56d 41m 06.0s, R=0.05) errorbox 11 sec after notice time and 35 sec after trigger time at 2024-11-27 21:43:51 UT, with upper limit up to 18.3 mag. The observations began at zenith distance = 61 deg. The sun altitude is -35.8 deg. The galactic latitude b = -47 deg., longitude l = 337 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2686277 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 41 | MASTER-SAAO | C | 10 | 13.0 | 56 | MASTER-SAAO | C | 40 | 17.9 | Coadd 70 | MASTER-SAAO | C | 10 | 17.5 | 104 | MASTER-SAAO | C | 20 | 17.9 | 143 | MASTER-SAAO | C | 20 | 16.7 | 178 | MASTER-SAAO | C | 90 | 18.3 | Coadd 187 | MASTER-SAAO | C | 30 | 17.7 | 241 | MASTER-SAAO | C | 40 | 17.9 | 305 | MASTER-SAAO | C | 50 | 15.7 | 379 | MASTER-SAAO | C | 60 | 14.9 | 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/38353. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36344] Swift GRB241127.91: Global MASTER-Net OT detection
by GCN Circulars 27 Nov '24

27 Nov '24

TITLE: GCN CIRCULAR NUMBER: 38352 SUBJECT: Swift GRB241127.91: Global MASTER-Net OT detection DATE: 24/11/27 21:48:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> D. Buckley (South African Astronomical Observatory), V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the GRB241127.91 19 sec after notice time and 35 sec after trigger time at 2024-11-27 21:43:51 UT. On our 3-th (20s exposure) set , obtained 93 sec after tigger time at 2024-11-27 21:44:49 UT, we found 1 optical transient within Swift error-box (ra=327.921 dec=-56.685 r=0.05) brighter than 17.4. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 103 2024-11-27 21:44:49 20 (21h 51m 32.48s , -56d 39m 55.8s) 15.5 The 5-sigma upper limit has been about 17.4mag The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38352. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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