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

[vsnet-grb-info 38470] GRB 250512B: SVOM detection of a burst
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40439 SUBJECT: GRB 250512B: SVOM detection of a burst DATE: 25/05/12 14:40:03 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Pierre Maggi (ObAS), Yinuo Ma (NAOC), Nicolas Dagoneau (CEA), Ulysse Jacob (LUPM), Miguel Moita (CEA) report on behalf of the SVOM mission team: SVOM/ECLAIRs triggered and located GRB 250512B (SVOM burst-id sb25051203) starting at 2025-05-12T11:20:08 (Tb), also detected by Einstein Probe (labelled as EP250512a, Zhao et al. GCN … [View More]40437). The following trigger information was received after data download through the X-band ground station. The burst was detected onboard both by the Count-Rate Trigger (CRT) and the Image Trigger (IMT), which produced a sequence of 16 alerts. CRT provided the alert with the best signal-to-noise-ratio (SNR) of 25.26 in the 8-120 keV energy band over a time window of 20.40 seconds starting at Tb. The localization of the best alert is R.A., Dec. 215.22, -10.1086 degrees with a 90% confidence level (C.L.) radius of 3.65 arcmin (including systematic error of 2 arcmin added in quadrature). The ECLAIRs light curve in the 4-120 keV energy band shows a single broad peak structure with a T90 duration of 23.76 (-2.50/+0.48) seconds. SVOM slewed to the burst. MXT began observing the field at 2025-05-12T11:22:58.718 UTC, 160 seconds after Tb. Using the X-band data we found an uncatalogued X-ray source located at R.A., Dec. 215.200, -10.1128 degrees: R.A. (J2000) = 14h20m48.1s Dec. (J2000) = -10d06m46.16s with a 90% C.L. radius of 40 arcseconds including 35 arcseconds added in quadrature. This location is 1.2 arcminutes from the ECLAIRs onboard position and 50 arcseconds from the EP/FXT one. The MXT source is rapidly fading and is not detected in the second orbit starting 1.5 hours after slew. VT began observing the field after the slew. The analysis of the recorded images will be published in a future circular gathering information on the follow-up of the SVOM optical instruments. The Space-based multi-band astronomical 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 CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE. The Burst Advocate (BA) on shift for this burst is Pierre Maggi: pierre.maggi(a)astro.unistra.fr. Please contact the BA by email if you require additional information regarding the SVOM follow-up of this burst. View this GCN Circular online at https://gcn.nasa.gov/circulars/40439. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

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[vsnet-grb-info 38469] GRB 250507B: SVOM/GRM observation of a burst
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40438 SUBJECT: GRB 250507B: SVOM/GRM observation of a burst DATE: 25/05/12 14:30:02 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Olivier Godet, Hui Yang (IRAP) report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by a burst GRB 250507B (SVOM trigger reference: sb25050704) at 2025-05-07T09:31:33.2 UTC (T0). With … [View More]

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[vsnet-grb-info 38468] EP250512a: Einstein Probe detection of an X-ray transient
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40437 SUBJECT: EP250512a: Einstein Probe detection of an X-ray transient DATE: 25/05/12 12:13:33 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> D. H. Zhao, M. J. Liu, J. W. Hu, H. W. Pan (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of an X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP250512a. The transient triggered EP-WXT (ID: 01709175718) at 2025-… [View More]

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[vsnet-grb-info 38467] GRB 250512A: Fermi GBM Final Real-time Localization
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40436 SUBJECT: GRB 250512A: Fermi GBM Final Real-time Localization DATE: 25/05/12 12:12:11 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 12:01:36 UT on 12 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250512A (trigger 768744101.290912 / 250512501). The on-ground calculated location, using the Fermi GBM trigger data, is RA =… [View More]

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[vsnet-grb-info 38466] EP250511a: REM optical/NIR observations
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40435 SUBJECT: EP250511a: REM optical/NIR observations DATE: 25/05/12 09:02:36 GMT FROM: Riccardo Brivio at INAF-OAB <riccardo.brivio(a)inaf.it> R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB EP250511a detected by EP/WXT (Lian et al., GCN 40429) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the … [View More]

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[vsnet-grb-info 38465] EP250511a: Einstein Probe follow-up obsevation and refined analysis
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40434 SUBJECT: EP250511a: Einstein Probe follow-up obsevation and refined analysis DATE: 25/05/12 06:36:55 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> A. Li (BNU), Y. L. Wang (NAO, CAS), T. Y. Lian (NAO, CAS), C. C. Jin (NAO, CAS) behalf of the Einstein Probe (EP) team: The X-ray transient EP250511a was detected by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission (Lian et al., GCN 40429), and followed up by several … [View More]

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[vsnet-grb-info 38464] EP250511a: SVOM/VT optical candidate comfirmation
by GCN Circulars 12 May '25

12 May '25

TITLE: GCN CIRCULAR NUMBER: 40433 SUBJECT: EP250511a: SVOM/VT optical candidate comfirmation DATE: 25/05/12 01:50:53 GMT FROM: Huali Li at at NAOC, SVOM <lhl(a)nao.cas.cn> H. L. Li, L. P. Xin, Y. L. Qiu, J. Wang, C. Wu, Z. H. Yao, Y. N. Ma, X. H. Han, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. S. Deng, J. Y. Wei, T. Y. Lian (NAOC), A. Li (BNU), Y. L. Wang (NAOC; ICE, CSIC-IEEC), C. C. Jin (NAOC) report on behalf of the SVOM and Einstein Probe (EP) teams: … [View More]

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[vsnet-grb-info 38463] EP250511a: Global MASTER-Net observations report
by GCN Circulars 11 May '25

11 May '25

TITLE: GCN CIRCULAR NUMBER: 40432 SUBJECT: EP250511a: Global MASTER-Net observations report DATE: 25/05/11 20:36:40 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E.… [View More] Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), 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 EP250511a ( EP Team et al., GCN 40429) errorbox 28887 sec after notice time and 44100 sec after trigger time at 2025-05-11 20:14:59 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 30 deg. The sun altitude is -55.6 deg. The galactic latitude b = 58 deg., longitude l = 322 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2867812 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 44115 | 2025-05-11 20:14:59 | MASTER-SAAO | (13h 27m 09.60s , -02d 50m 52.7s) | C | 30 | 16.8 | 44220 | 2025-05-11 20:14:59 | MASTER-SAAO | (13h 27m 09.60s , -02d 50m 52.5s) | C | 240 | 16.8 | Coadd 44165 | 2025-05-11 20:15:48 | MASTER-SAAO | (13h 27m 07.01s , -02d 49m 12.4s) | C | 30 | 16.9 | 44259 | 2025-05-11 20:16:38 | MASTER-SAAO | (13h 27m 08.05s , -02d 50m 48.6s) | C | 120 | 16.7 | 44399 | 2025-05-11 20:18:57 | MASTER-SAAO | (13h 27m 12.36s , -02d 49m 05.6s) | C | 120 | 16.8 | 44538 | 2025-05-11 20:21:16 | MASTER-SAAO | (13h 27m 08.49s , -02d 49m 44.1s) | C | 120 | 16.6 | 44707 | 2025-05-11 20:23:36 | MASTER-SAAO | (13h 27m 08.91s , -02d 48m 40.9s) | C | 180 | 15.3 | 44907 | 2025-05-11 20:26:55 | MASTER-SAAO | (13h 27m 18.75s , -02d 49m 37.8s) | C | 180 | 16.1 | 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/40432. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

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[vsnet-grb-info 38462] EP250511a: COLIBRÍ optical counterpart candidate
by GCN Circulars 11 May '25

11 May '25

TITLE: GCN CIRCULAR NUMBER: 40431 SUBJECT: EP250511a: COLIBRÍ optical counterpart candidate DATE: 25/05/11 14:01:49 GMT FROM: Benjamin Schneider at MIT <bschn(a)mit.edu> Benjamin Schneider (LAM), Kin Ocelotl López (UNAM), Rosa L. Becerra (U Roma), Camila Angulo (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Alan M. Watson (UNAM), Fredd Alvarez (UNAM), Jean-Luc Atteia (IRAP), Dalya Akl (AUS), Sarah Antier (OCA), Nathaniel R. Butler (ASU) , Damien Dornic (CPPM), Jean-… [View More]

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[vsnet-grb-info 38461] EP250511a: BOOTES-5 optical upper limit
by GCN Circulars 11 May '25

11 May '25

TITLE: GCN CIRCULAR NUMBER: 40430 SUBJECT: EP250511a: BOOTES-5 optical upper limit DATE: 25/05/11 12:27:11 GMT FROM: I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg(a)iaa.es> I. Perez-Garcia, E. J. Fernandez-Garcia, M. D. Caballero-Garcia, S.-Y. Wu, R. Sanchez-Ramirez, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), I. M. Carrasco (SMA), M. Gritsevich (Univ. of Helsinki), C. Perez del Pulgar (Univ. of Malaga), Y.-D. Hu (GXU), S. Jeong (ADD, Daejeon), G. … [View More]

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