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

[vsnet-grb-info 42744] GRB 260510C: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44616 SUBJECT: GRB 260510C: CALET Gamma-Ray Burst Monitor detection DATE: 26/05/15 07:23:20 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> T. Sakamoto, A. Yoshida, 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), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) detected GRB 260510C (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN #44520; SVOM detection of a burst: Gotz et al., GCN #44521; MAXI/GSC detection: Iwakiri et al., GCN #44526; AstroSat CZTI detection: Arya et al., GCN #44544; Fermi GBM Observation: Palafox et al., GCN #44564) at 17:15:37.60 UTC on 10 May 2026 (https://cgbm.calet.jp/cgbm_trigger/flight/1462468483/index.html) The burst signal was seen by all CGBM detectors. The onboard CGBM trigger corresponds to the second peak of the double-peaked structure reported by Fermi/GBM and SVOM/ECLAIRs. In the CGBM ground analysis, the first peak was also marginally visible in the SGM data. The second peak started at T+0.3 s, peaked at T+2.9 s, and ended at T+8.9 s. The T90 and T50 durations of the second peak, measured with the SGM data, are 7.4 +/- 0.8 s and 3.2 +/- 0.8 s in the 40-1000 keV band, respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1462468483/ The CALET data used in this analysis were provided by the Waseda CALET Operation Center located at Waseda University. View this GCN Circular online at https://gcn.nasa.gov/circulars/44616. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42743] GRB 260511B: GMG Optical Upper Limit
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44615 SUBJECT: GRB 260511B: GMG Optical Upper Limit DATE: 26/05/15 04:58:07 GMT FROM: Rui-Zhi Li at Yunnan Observatories, CAS <liruizhi(a)ynao.ac.cn> R.-Z. Li, B.-T. Wang, F.-F. Song, J. Mao, J.-G. Wang and B. Wang (YNAO, CAS) report: We observed the field of GRB 260511B (Godet et al., GCN 44543, T0 at 2026-05-11T11:00:32) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2026-05-14 12:45:02, about 73.74 hours after the trigger. The optical counterpart (Wu et al. GCN 44547, Sasada et al. GCN 44549, Jiang et al. GCN 44551, Wu et al. GCN 44552, Vijaykumar et al. GCN 44561, de Ugarte Postigo et al. GCN 44565, Lee et al. GCN 44567, Li et al. GCN 44568, Wang et al. GCN 44571, Belkin et al. GCN 44572, Adami et al. GCN 44573, Saccardi et al. GCN 44574, Rajabov et al. GCN 44576, Perez-Fournon et al. GCN 44577, Novotny et al. GCN 44580, Moskvitin et al. GCN 44582, Calapai et al. GCN 44592, Moskvitin et al. GCN 44600 and Liu et al. GCN 44610) of GRB 260511B was not detected in our r-band image. The preliminary analysis results are shown as follows: +-------------------------+----------------+---------------+----------+----------------+ | Start time [UTC] | Exposure [s] | Tmid-T0 [h] | Filter | 5-sigma U.L. | +=========================+================+===============+==========+================+ | 2026-05-14 12:45:02.730 | 900 | 73.867 | r | 21.6 | +-------------------------+----------------+---------------+----------+----------------+ The given magnitudes are derived based on calibrating against Pan-STARRS1 field stars. View this GCN Circular online at https://gcn.nasa.gov/circulars/44615. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42742] EP260514a: Global MASTER-Net observations report
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44614 SUBJECT: EP260514a: Global MASTER-Net observations report DATE: 26/05/15 03:27:20 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. 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP260514a ( EP Team et al., GCN 44613) errorbox 35348 sec after trigger time at 2026-05-15 02:45:14 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 81 deg. The sun altitude is -63.2 deg. The galactic latitude b = 62 deg., longitude l = 91 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3315353 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 35378 | 2026-05-15 02:45:14 | MASTER-OAFA | (14h 15m 58.14s , +49d 22m 48.5s) | C | 60 | 18.0 | 35443 | 2026-05-15 02:46:19 | MASTER-OAFA | (14h 15m 57.12s , +49d 22m 52.2s) | C | 60 | 18.0 | 35509 | 2026-05-15 02:47:24 | MASTER-OAFA | (14h 15m 56.10s , +49d 22m 55.1s) | C | 60 | 18.3 | 35575 | 2026-05-15 02:48:31 | MASTER-OAFA | (14h 15m 54.95s , +49d 22m 57.3s) | C | 60 | 18.2 | 35641 | 2026-05-15 02:49:37 | MASTER-OAFA | (14h 15m 54.43s , +49d 23m 01.2s) | C | 60 | 18.3 | 35701 | 2026-05-15 02:49:37 | MASTER-OAFA | (14h 15m 54.41s , +49d 23m 01.1s) | C | 180 | 18.6 | Coadd 35707 | 2026-05-15 02:50:42 | MASTER-OAFA | (14h 15m 54.22s , +49d 23m 03.8s) | C | 60 | 18.2 | 35773 | 2026-05-15 02:51:49 | MASTER-OAFA | (14h 15m 54.02s , +49d 23m 06.1s) | C | 60 | 17.9 | 35838 | 2026-05-15 02:52:54 | MASTER-OAFA | (14h 15m 53.77s , +49d 23m 08.7s) | C | 60 | 18.0 | 35904 | 2026-05-15 02:53:59 | MASTER-OAFA | (14h 15m 53.54s , +49d 23m 11.4s) | C | 60 | 18.1 | 35970 | 2026-05-15 02:55:05 | MASTER-OAFA | (14h 15m 53.30s , +49d 23m 11.7s) | C | 60 | 18.2 | 36035 | 2026-05-15 02:56:11 | MASTER-OAFA | (14h 15m 53.06s , +49d 23m 14.8s) | C | 60 | 18.4 | 36101 | 2026-05-15 02:57:16 | MASTER-OAFA | (14h 15m 52.80s , +49d 23m 16.2s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/44614. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42741] EP260514a: Einstein Probe detection of a fast X-ray transient
by GCN Circulars 15 May '26

15 May '26

TITLE: GCN CIRCULAR NUMBER: 44613 SUBJECT: EP260514a: Einstein Probe detection of a fast X-ray transient DATE: 26/05/15 03:20:32 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.-H. Cheng (SWIFAR, YNU), K.R. Ni (CCNU), R.-Z. Li (YNAO, CAS) and W.-D. Zhang (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of a fast X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP260514a. The ground analysis of the WXT data shows that the event started at T0 = 2026-05-14T16:56:06 (UTC) and lasted for around 500 s. The WXT position of the source is R.A. = 214.297 deg, DEC = 49.365 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). A follow-up observation with the Follow-up X-ray Telescope (FXT) on board EP has been scheduled. Further information will be updated when the telemetry data is received. 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/44613. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42740] EP260512a: LCO optical upper limits
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44612 SUBJECT: EP260512a: LCO optical upper limits DATE: 26/05/14 18:45:03 GMT FROM: Jonathan Quirola at Radboud University <jaquirola1990(a)gmail.com> J. Quirola-Vasquez (Radboud), R. A. J. Eyles-Ferris (Leicester), G. Corcoran (UCD), P. G. Jonker (Radboud), M. Fraser (UCD), A. J. Levan (Radboud & Warwick) and D. B. Malesani (DAWN/NBI and Radboud), J. A. Chacón (PUC), F. E. Bauer (SSI and UTA), report on behalf of a larger collaboration: We observed the field of the X-ray transient EP260512a (Liang et al., GCN 44594) using LCO 1m telescopes located at the McDonald Observatory (USA) equipped with SINISTRO instruments. A series of 6x300 s exposures was taken using the SDSS-r filter, starting at 2026-05-13 06:54:11 UT (i.e., ~0.93 days after the first X-ray detection). No new source is detected within or at the border of the EP/WXT (Liang et al., GCN 44594) uncertainty region compared with the Legacy Survey. From the stacked images, we obtain the following 3-sigma upper limits:  r > 22.2 These upper limits are in AB magnitudes, calibrated using nearby stars from the PanSTARRS catalogue, and are not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/44612. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42739] IPN triangulation of GRB 260512A
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44611 SUBJECT: IPN triangulation of GRB 260512A DATE: 26/05/14 15:55:38 GMT FROM: Dmitry Svinkin at Ioffe Institute <dmitrysvinkin(a)gmail.com> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi-GBM 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 long-duration GRB 260512A (Ferm-GBM detection: The Fermi GBM team, GCN 44587; NuSTAR-ACS detection: Waratkar et al., GCN 44591; AstroSat-CZTI detection: Tembhurnikar et al., GCN 44608) was detected by Fermi (GBM trigger 800297808), Konus-Wind, NuSTAR (ACS), AstroSat (CZTI), and Mars-Odyssey (HEND) at about 61003 s UT (16:56:43). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 131.305 (08h 45m 13s) -83.033 (-83d 02' 00") Corners: 128.432 (08h 33m 44s) -81.525 (-81d 31' 31") 128.203 (08h 32m 49s) -81.573 (-81d 34' 22") 135.825 (09h 03m 18s) -84.513 (-84d 30' 48") 136.100 (09h 04m 24s) -84.461 (-84d 27' 41") --------------------------------------------- The error box area is 485 sq. arcmin, and its maximum dimension is 3.1 deg (the minimum one is 2.6 arcmin). The Sun distance was 106 deg. This localization may be improved. A triangulation map and HEALPix FITS files are posted at http://www.ioffe.ru/LEA/GRBs/GRB260512_T61005/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/44611. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42738] GRB 260511B: Mephisto multi-band optical followup
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44610 SUBJECT: GRB 260511B: Mephisto multi-band optical followup DATE: 26/05/14 15:51:44 GMT FROM: Brajesh Kumar at SWIFAR, YNU <brajesh(a)ynu.edu.cn> Chenxu Liu, Chenxi Shang, Guowang Du, Brajesh Kumar, Xian Liu, Haipeng Lei, Weikang Lin, Yu Pan, Xingzhu Zou, Xinlei Chen, Yuan Fang, Jinghua Zhang, Xufeng Zhu, Tao Wang, Xinzhong Er, Yuanpei Yang (SWIFAR, YNU), Chao Wu (NAOC), Xiangkun Liu, Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team: We performed simultaneous multi-band (uvgriz) photometric observations of GRB 260511B (Godet et al., GCN 44543) at 2026-05-12T16:17:44 (~1.2d after the the SVOM/ECLAIRs trigger) using the 1.6-m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University, located at the Lijiang Observatory. The optical counterpart was clearly detected in our stacked images and preliminary photometry is listed below (without Galactic extinction correction): ------------------------------------------------------- Start Time (UT) | Band | Exp(s) | Mag (AB) ------------------------------------------------------- 2026-05-12T16:17:44 | u | 300*2 | 22.45 (+/-0.20) 2026-05-12T16:29:15 | v | 300*2 | 21.77 (+/-0.19) 2026-05-12T16:17:47 | g | 300*2 | 21.19 (+/-0.08) 2026-05-12T16:29:17 | r | 300*2 | 21.03 (+/-0.07) 2026-05-12T16:17:46 | i | 300*2 | 20.70 (+/-0.11) 2026-05-12T16:29:17 | z | 300*2 | 20.40 (+/-0.16) These results are consistent with previous optical observations reported by Wu et al. (GCN 44547), Sasada et al. (GCN 44549), Jiang et al. (GCN 44551), Wu et al. (GCN 44552), Vijaykumar et al. (GCN 44561), de Ugarte Postigo et al. (GCN 44565), Lee et al. (GCN 44567), Li et al. (GCN 44568), Wang et al. (GCN 44571), Belkin et al. (GCN 44572), Adami et al. (GCN 44573), Saccardi et al. (GCN 44574), Rajabov et al. (GCN 44576), Perez-Fournon et al. (GCN 44577), Novotny et al. (GCN 44580), Moskvitin et al. (GCN 44582), Calapai et al. (GCN 44592), and Moskvitin et al. (GCN 44600). ---------------------------------------------------------------------------------------------------- Mephisto (Multi-channel Photometric Survey Telescope) is a 1.6-m 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. The facility is operated by the South-Western Institute for Astronomy Research (SWIFAR), Yunnan University. It provides real-time, high-quality colors of stellar objects. The Mephisto mosaic cameras were installed in October 2025. The first light was achieved in all three channels on 10 October 2025 and presently, these are under the commissioning phase. All the data have been reduced by the Mephisto data processing pipeline. We note that the current data-processing pipeline is still at a preliminary stage, with flux calibration precision of about 2% in the u and v bands, about 1% in the g and r bands, and better than 1% in the i and z bands. View this GCN Circular online at https://gcn.nasa.gov/circulars/44610. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42737] Fermi GRB 260514A: Global MASTER-Net observations report
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44609 SUBJECT: Fermi GRB 260514A: Global MASTER-Net observations report DATE: 26/05/14 11:15:36 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. 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 260514A ( Fermi GBM team, GCN 44604) errorbox 19843 sec after notice time and 19904 sec after trigger time at 2026-05-14 10:28:25 UT, with upper limit up to 17.1 mag. Observations started at twilight. The observations began at zenith distance = 71 deg. The sun altitude is -10.0 deg. The galactic latitude b = 15 deg., longitude l = 334 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3313250 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 19935 | 2026-05-14 10:28:25 | MASTER-OAFA | (15h 23m 20.52s , -37d 30m 31.8s) | C | 60 | 16.6 | 20013 | 2026-05-14 10:29:43 | MASTER-OAFA | (15h 23m 26.39s , -37d 31m 33.2s) | C | 60 | 17.1 | 20088 | 2026-05-14 10:30:58 | MASTER-OAFA | (15h 23m 19.45s , -39d 52m 36.3s) | C | 60 | 17.1 | 20165 | 2026-05-14 10:32:15 | MASTER-OAFA | (15h 23m 25.28s , -39d 52m 31.6s) | C | 60 | 17.1 | 20244 | 2026-05-14 10:33:34 | MASTER-OAFA | (15h 23m 24.08s , -34d 50m 45.0s) | C | 60 | 16.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/44609. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42736] GRB 260512A: AstroSat CZTI detection
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44608 SUBJECT: GRB 260512A: AstroSat CZTI detection DATE: 26/05/14 10:11:36 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910(a)gmail.com> M. Tembhurnikar (IUCAA), Harsha K. H. (IUCAA), S. Salunke (IUCAA), A. Arya (IITB), A. Goyal (IITB), G. Waratkar (Caltech/IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 260512A which was also detected by Fermi/GBM (Fermi GBM team, GCN Circ. 44587), and NuSTAR (Waratkar et. al. , GCN Circ. 44591). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-05-12 16:56:47.5 UTC. The measured peak count rate associated with the burst is 302 (+33, -31) counts/s above the background in the combined data of two quadrants (out of four), with a total of 1755 (+142, -215) counts. The local mean background count rate was 159 (+2, -5) counts/s. We measure a T90 of 13 (+1, -1) s from the cumulative CZT light curve. The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-05-12 16:56:46.4 UTC. The measured peak count rate associated with the burst is 655 (+88, -70) counts/s above the background in the combined data of all quadrants, with a total of 3682 (+588, -378) counts.The local mean background count rate was 1822 (+7, -14) counts/s. We measure a T90 of 10 (+2, -2) s from the cumulative Veto light curve. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb View this GCN Circular online at https://gcn.nasa.gov/circulars/44608. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42735] The EP-WXT trigger 01709262077 is likely a flaring star
by GCN Circulars 14 May '26

14 May '26

TITLE: GCN CIRCULAR NUMBER: 44607 SUBJECT: The EP-WXT trigger 01709262077 is likely a flaring star DATE: 26/05/14 09:39:59 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> S. Q. Jiang (NAO, CAS), C. Y. Dai (NJU), H. Y. Ren, H. W. Pan (NAO, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709262077 at the time of 2026-05-14T08:58:30, is likely a stellar flare associated with the high proper motion star Gaia DR3 5390947154990629248. The estimated flux of the flare is around 8.6 × 10^(-11) erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 1.0 × 10^(31) erg/s. 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/44607. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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