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

[vsnet-grb-info 40250] SVOM/sb25101004: SVOM detection of a stellar flare
by GCN Circulars 10 Oct '25

10 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42180 SUBJECT: SVOM/sb25101004: SVOM detection of a stellar flare DATE: 25/10/10 07:23:03 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Donghua ZHAO, Chao Wu, Wenjin Xie (NAOC), Hatsunegoto Goto(Kanazawa Univ./CEA)，Florent Robinet (IJCLab), Nicolas Dagoneau, J. T. Palmerio (CEA) report on behalf of the SVOM mission team At 2025-10-10T03:51:58 UTC (T0), SVOM/ECLAIRs triggered and located the source (SVOM burst-id sb25101004). The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network. The source was only detected by the Image Trigger (IMT), which produced a sequence of 5 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 9.82 in the [5-20] keV energy band over a time window of 327.68 seconds starting at 2025-10-10T03:47:53. The localization of the best alert is R.A., Dec.: 311.3214, -31.4119 degrees (J2000) with a 90% confidence level (C.L.) radius of 8.10 arcmin (including systematic error of 2 arcmin added in quadrature). SVOM slewed to the source. SVOM/MXT began observing the field at 2025-10-10T04:00:23 UTC, 505 seconds after T0. Using X band data we found a source located at R.A., Dec.: 311.2972, -31.3445 degrees: R.A. (J2000) = 20h45m11.338s Dec. (J2000) = -31d20m40.213s with a 90% C.L. radius of 25.8 arcseconds (including a systematic error of 25 arcsec added in quadrature). This location is 4.23 arcminutes from the ECLAIRs onboard position. No uncatalogued fading X-ray counterpart was detected. There is a known source HD 197481 (Au Mic: a young red dwarf star ) which is 4.23 arcmin away from ECLAIRs position and is 26 arcsec away from MXT position. These results show that this trigger is probably caused by the stellar flare of HD 197481 (Au Mic). 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. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE. The Burst Advocate (BA) on shift for this alert is Donghua Zhao: zhaodh(a)bao.ac.cn. Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/42180. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40249] GRB 251009A: Fermi GBM Final Localization
by GCN Circulars 10 Oct '25

10 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42179 SUBJECT: GRB 251009A: Fermi GBM Final Localization DATE: 25/10/10 00:04:26 GMT FROM: Matt Godwin <msg0028(a)uah.edu> The Fermi GBM team reports the detection of a likely SHORT GRB "At 15:58:56.61 UT on 09 October 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251009A (trigger 781718341/251009666). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 72.05, Dec = -25.84 (J2000 degrees, equivalent to J2000 4h 48m, -25d 50'), with a statistical uncertainty of 25.22 degrees. The angle from the Fermi LAT boresight is 86 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251009666/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251009666/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251009666/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/42179. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40248] GRB 250916A: TERI Gamma-ray detection
by GCN Circulars 09 Oct '25

09 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42178 SUBJECT: GRB 250916A: TERI Gamma-ray detection DATE: 25/10/09 21:13:22 GMT FROM: Daniel Shy <danielshy(a)danielshy.com> Daniel Shy (a), C.C. Cheung (a), Bernard Phlips (a), Michael Streicher (b), James Mason (b), Douglas M. Groves (b), Feng Zhang (b), Willy Kaye (b) (a) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 250916A, which was also detected by Fermi/GBM (Fermi GBM Team, GCN Circ., 41839), Astrosat/CZTI (Arya et al., GCN Circ. 41843), Glowbug (Cheung et al., GCN Circ. 41855), CALET/GBM (Trig ID. 1442064382), and NuSTAR (41871). Using 1 Hz binning, the peak count rate is roughly 23 excess counts per second (cps) at ~T0+259s (adopting T0 = 2025-09-16 13:29:21.1) over a baseline rate of 41-cps observed in nearby off-source intervals. We do not detect the initial faint burst at T0 detected by Fermi/GBM. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program’s STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42178. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40247] GRB 250919A: TERI gamma-ray detection
by GCN Circulars 09 Oct '25

09 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42177 SUBJECT: GRB 250919A: TERI gamma-ray detection DATE: 25/10/09 21:09:21 GMT FROM: Daniel Shy <danielshy(a)danielshy.com> Daniel Shy (a), C.C. Cheung (a), Bernard Phlips (a), Michael Streicher (b), James Mason (b), Douglas M. Groves (b), Feng Zhang (b), Willy Kaye (b) (a) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 250919A, which was also detected by Fermi/GBM, SVOM/GRM, EP/WXT, NuSTAR, Glowbug, Insight-HXMT, and Konus-Wind (Fermi GBM team, GCN 41874; Wang et al., GCN 41882; Liang et al., GCN 41879; Waratkar & Grefenstette, GCN 41888; Cheung et al., GCN 41891, Wang et al., GCN 41900; Frederiks et al., GCN 41905) Using 1 Hz binning, and adopting T0 = 2025-09-19 00:28:52.28, we observe the three dominant peaks seen in the Fermi/GBM lightcurve (GCN 41874) at ~T0+24s, ~T0+26s, and ~T0+29s with respective peak excess count rates of roughly 57, 171, and 104 counts per second (cps) above the 27-cps baseline rate observed in nearby off-source intervals. We do not observe the fainter, leading feature at ~T0, as seen in the Fermi/GBM lightcurve. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program’s STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42177. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40246] EP251006a: Global MASTER-Net observations report
by GCN Circulars 09 Oct '25

09 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42176 SUBJECT: EP251006a: Global MASTER-Net observations report DATE: 25/10/09 20:18:28 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-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) was pointed to the EP251006a ( EP Team et al., GCN 42137) errorbox 196 sec after trigger time at 2025-10-07 18:11:57 UT, with upper limit up to 16.6 mag. The observations began at zenith distance = 79 deg. The sun altitude is -37.7 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) was pointed to the EP251006a errorbox 3541 sec after trigger time at 2025-10-07 19:07:42 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 75 deg. The sun altitude is -29.6 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP251006a errorbox 40526 sec after trigger time at 2025-10-08 05:24:07 UT, with upper limit up to 18.7 mag. The observations began at zenith distance = 27 deg. The sun altitude is -50.3 deg. The galactic latitude b = -56 deg., longitude l = 180 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3010044 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 226 | 2025-10-07 18:11:57 | MASTER-Kislovodsk | (02h 39m 56.00s , -06d 09m 59.8s) | C | 60 | 14.6 | 226 | 2025-10-07 18:11:57 | MASTER-Kislovodsk | (02h 39m 54.59s , -05d 47m 17.6s) | C | 60 | 15.4 | 508 | 2025-10-07 18:16:38 | MASTER-Kislovodsk | (02h 39m 49.79s , -05d 48m 02.3s) | C | 60 | 15.5 | 508 | 2025-10-07 18:16:38 | MASTER-Kislovodsk | (02h 39m 51.52s , -06d 10m 40.5s) | C | 60 | 14.6 | 823 | 2025-10-07 18:21:54 | MASTER-Kislovodsk | (02h 39m 48.84s , -05d 45m 43.0s) | C | 60 | 15.5 | 883 | 2025-10-07 18:21:54 | MASTER-Kislovodsk | (02h 39m 48.82s , -05d 45m 42.9s) | C | 180 | 16.2 | Coadd 823 | 2025-10-07 18:21:54 | MASTER-Kislovodsk | (02h 39m 51.15s , -06d 08m 22.6s) | C | 60 | 14.9 | 903 | 2025-10-07 18:23:14 | MASTER-Kislovodsk | (02h 39m 51.14s , -06d 10m 23.8s) | C | 60 | 14.9 | 903 | 2025-10-07 18:23:14 | MASTER-Kislovodsk | (02h 39m 48.76s , -05d 47m 43.3s) | C | 60 | 15.5 | 1250 | 2025-10-07 18:29:00 | MASTER-Kislovodsk | (02h 39m 55.32s , -05d 47m 15.7s) | C | 60 | 15.6 | 1250 | 2025-10-07 18:29:00 | MASTER-Kislovodsk | (02h 39m 57.09s , -06d 10m 09.1s) | C | 60 | 14.6 | 3572 | 2025-10-07 19:07:42 | MASTER-SAAO | (02h 38m 20.93s , -06d 05m 34.6s) | C | 60 | 17.0 | 3572 | 2025-10-07 19:07:42 | MASTER-SAAO | (02h 40m 07.46s , -06d 21m 24.6s) | C | 60 | 13.5 | 40556 | 2025-10-08 05:24:07 | MASTER-OAFA | (02h 38m 04.24s , -06d 11m 37.8s) | C | 60 | 18.6 | 40631 | 2025-10-08 05:25:22 | MASTER-OAFA | (02h 38m 03.16s , -06d 10m 39.1s) | C | 60 | 18.6 | 40868 | 2025-10-08 05:29:18 | MASTER-OAFA | (02h 38m 02.78s , -06d 12m 42.4s) | C | 60 | 18.7 | 40945 | 2025-10-08 05:30:36 | MASTER-OAFA | (02h 46m 13.59s , -06d 12m 15.1s) | C | 60 | 18.7 | 41021 | 2025-10-08 05:31:52 | MASTER-OAFA | (02h 46m 09.43s , -06d 10m 39.7s) | C | 60 | 18.6 | 41099 | 2025-10-08 05:33:10 | MASTER-OAFA | (02h 46m 09.23s , -06d 12m 05.1s) | C | 60 | 18.6 | 43486 | 2025-10-08 06:12:57 | MASTER-OAFA | (02h 46m 25.97s , -05d 55m 21.1s) | C | 60 | 18.7 | 43564 | 2025-10-08 06:14:15 | MASTER-OAFA | (02h 46m 30.99s , -05d 55m 10.3s) | C | 60 | 18.7 | 43638 | 2025-10-08 06:15:29 | MASTER-OAFA | (02h 46m 28.25s , -05d 53m 31.6s) | C | 60 | 18.7 | 86664 | 2025-10-08 18:12:34 | MASTER-Kislovodsk | (02h 39m 48.87s , -05d 45m 56.5s) | C | 60 | 15.5 | 86724 | 2025-10-08 18:12:34 | MASTER-Kislovodsk | (02h 39m 48.87s , -05d 45m 56.4s) | C | 180 | 16.0 | Coadd 86664 | 2025-10-08 18:12:34 | MASTER-Kislovodsk | (02h 39m 49.14s , -06d 09m 00.5s) | C | 60 | 14.8 | 86744 | 2025-10-08 18:13:54 | MASTER-Kislovodsk | (02h 39m 58.79s , -05d 49m 41.8s) | C | 60 | 15.4 | 86744 | 2025-10-08 18:13:54 | MASTER-Kislovodsk | (02h 39m 59.30s , -06d 12m 47.1s) | C | 60 | 14.1 | 87245 | 2025-10-08 18:22:15 | MASTER-Kislovodsk | (02h 39m 49.23s , -05d 46m 24.8s) | C | 60 | 15.4 | 87245 | 2025-10-08 18:22:15 | MASTER-Kislovodsk | (02h 39m 52.54s , -06d 09m 03.4s) | C | 60 | 15.4 | 88594 | 2025-10-08 18:44:45 | MASTER-Kislovodsk | (02h 39m 53.25s , -05d 46m 54.7s) | C | 60 | 15.8 | 88654 | 2025-10-08 18:44:45 | MASTER-Kislovodsk | (02h 39m 53.24s , -05d 46m 54.5s) | C | 180 | 16.6 | Coadd 88594 | 2025-10-08 18:44:45 | MASTER-Kislovodsk | (02h 39m 57.09s , -06d 10m 00.7s) | C | 60 | 16.3 | 88935 | 2025-10-08 18:50:26 | MASTER-Kislovodsk | (02h 39m 52.51s , -05d 45m 44.1s) | C | 60 | 16.0 | 88935 | 2025-10-08 18:50:26 | MASTER-Kislovodsk | (02h 39m 58.82s , -06d 08m 32.2s) | C | 60 | 16.4 | 89015 | 2025-10-08 18:51:46 | MASTER-Kislovodsk | (02h 39m 58.46s , -05d 46m 41.6s) | C | 60 | 16.0 | 89015 | 2025-10-08 18:51:46 | MASTER-Kislovodsk | (02h 40m 04.85s , -06d 09m 31.8s) | C | 60 | 16.3 | 89095 | 2025-10-08 18:53:06 | MASTER-Kislovodsk | (02h 39m 48.54s , -05d 44m 54.1s) | C | 60 | 15.9 | 89155 | 2025-10-08 18:53:06 | MASTER-Kislovodsk | (02h 39m 48.54s , -05d 44m 54.2s) | C | 180 | 16.6 | Coadd 89095 | 2025-10-08 18:53:06 | MASTER-Kislovodsk | (02h 39m 55.02s , -06d 07m 45.0s) | C | 60 | 16.4 | 89175 | 2025-10-08 18:54:25 | MASTER-Kislovodsk | (02h 39m 54.56s , -05d 46m 36.7s) | C | 60 | 16.0 | 89175 | 2025-10-08 18:54:25 | MASTER-Kislovodsk | (02h 40m 01.09s , -06d 09m 28.4s) | C | 60 | 16.2 | 89255 | 2025-10-08 18:55:46 | MASTER-Kislovodsk | (02h 39m 54.62s , -05d 44m 51.0s) | C | 60 | 16.1 | 89255 | 2025-10-08 18:55:46 | MASTER-Kislovodsk | (02h 40m 01.20s , -06d 07m 42.8s) | C | 60 | 16.4 | 89335 | 2025-10-08 18:57:06 | MASTER-Kislovodsk | (02h 40m 00.54s , -05d 48m 27.7s) | C | 60 | 15.9 | 89335 | 2025-10-08 18:57:06 | MASTER-Kislovodsk | (02h 40m 07.15s , -06d 11m 19.7s) | C | 60 | 16.3 | 89937 | 2025-10-08 19:07:07 | MASTER-Kislovodsk | (02h 39m 50.59s , -05d 42m 57.7s) | C | 60 | 16.1 | 89937 | 2025-10-08 19:07:07 | MASTER-Kislovodsk | (02h 39m 56.71s , -06d 06m 09.4s) | C | 60 | 16.4 | 90017 | 2025-10-08 19:08:27 | MASTER-Kislovodsk | (02h 39m 53.56s , -05d 47m 41.3s) | C | 60 | 16.0 | 90017 | 2025-10-08 19:08:27 | MASTER-Kislovodsk | (02h 39m 59.66s , -06d 10m 54.2s) | C | 60 | 16.4 | 111807 | 2025-10-09 01:11:38 | MASTER-SAAO | (02h 41m 40.45s , -06d 20m 51.9s) | C | 60 | 18.2 | 111807 | 2025-10-09 01:11:38 | MASTER-SAAO | (02h 39m 51.83s , -06d 05m 32.4s) | C | 60 | 18.5 | 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/42176. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40245] GRB 251006A: Fermi GBM Observation
by GCN Circulars 09 Oct '25

09 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42175 SUBJECT: GRB 251006A: Fermi GBM Observation DATE: 25/10/09 15:08:56 GMT FROM: Eva MP <eva.palafox(a)gmail.com> E. Palafox (INAOE), M. Godwin (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 13:27:35.03 UT on 06 October 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251006A (trigger 781450060/251006561), which was also detected by Swift/BAT-GUANO (J. DeLaunay et al. 2025, GCN 42144) and Glowbug (C. C. Cheung et al. 2025, GCN 42130). The Fermi GBM on-ground location is consistent with the Swift/BAT-GUANO position. The angle from the Fermi LAT boresight is 30 degrees. The GBM light curve consists of one short emission with total duration (T90) of about 1.4 s (50-300 keV). The time-averaged spectrum from T0-0.3 to T0+0.3 s is best fit by a Comptonized function with Epeak of 490 +/- 170 and alpha of -0.9 +/- 0.2. The event fluence (10-1000 keV) in this time interval is (4.8 +/- 0.6)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0.0 s in the 10-1000 keV band is 7 +/- 1 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/42175. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40244] GRB 251007A: 1.5m OSN and 2.2m CAHA optical follow-up
by GCN Circulars 09 Oct '25

09 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42174 SUBJECT: GRB 251007A: 1.5m OSN and 2.2m CAHA optical follow-up DATE: 25/10/09 11:20:11 GMT FROM: Youdong HU at INAF-OAB <huyoudong072(a)hotmail.com> Y.-D. Hu (GXU), F. Aceituno, A. J. Castro-Tirado, E. Fernandez-Garcia, I. Perez-Garcia, S.-Y. Wu, M. D. Caballero-Garcia, R. Sanchez-Ramirez, and S. Guziy (IAA-CSIC) and A. Fernández-Martín (CAHA) on behalf of a larger collaboration, report: Following the detection of GRB 251007A by Swift (Ambrosi et al. GCNC 42146), we triggered the 1.5m OSN telescope in Granada (Spain) starting on Oct. 08 at 04:17:06 UT (~8.8 hrs post burst), a series of I-band image was gathered. In the stacked image, the optical afterglow is detected within the Swift/XRT error region (Beardmore et al. GCNC 42161) with I=21.21+-0.19. About 20 mins later, the 2.2m CAHA telescope (+ CAFOS) at the Calar Alto Observatory (Almeria, Spain) also triggered to start taking images with Sloan-griz filters. The optical afterglow is detected in the stacked image with i=22.0+-0.3. These detections are consistent with the reports from UVOT (Ambrosi et al. GCNC 42146), MASTER (Lipunov et al. GCNC 42149), SVOM/C-GFT (Wu et al. GCNC 42154), AKO (Odeh et al. GCNC 42157), NOT (Malesani et al. GCNC 42158) and SVOM/VT (Li et al. GCNC 42163). We thank the staff at OSN and Calar Alto observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/42174. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40243] GRB 251002A - SVOM/ECLAIRs refined analysis
by GCN Circulars 09 Oct '25

09 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42173 SUBJECT: GRB 251002A - SVOM/ECLAIRs refined analysis DATE: 25/10/09 06:55:38 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> M. G. Bernardini (INAF-OAB, LUPM), U. Jacob, F. Piron (LUPM), M. Brunet, O. Godet (IRAP), N. Dagoneau, B. Hubert, S. Schanne, A. Saccardi, D. Gotz (CEA/Irfu) Using the event-by-event data downloaded through the X-band ground stations, we report further analysis of ECLAIRs observations of GRB 251002A (SVOM burst-id sb25100211). The burst that triggered ECLAIRs onboard (Saccardi et al., GCN Circ. 42060) consists of a multiple peak structure with a duration of T90 = (8.2 -0.3/+1.82) s in the 4-120 keV energy band. After this main emission episode, the source is still visible through image deconvolution as a dim source up to about 30 s after T0 (T0 = 2025-10-02T20:14:54 s). The time-averaged spectrum from T0-3 s to T0+8 s in the energy range 5-120 keV is best fitted by a cutoff power law model with index (0.72 +0.18/-0.20) and E0 = (79 +68/-26) keV. With this model, the total 4-120 keV fluence is (2.57 +/-0.03)e-6 erg/cm^2. All the quoted errors are at the 68% confidence level. 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. The SVOM/ECLAIRs point of contact for this burst is: M. G. Bernardini (INAF-OAB, LUPM) (maria.bernardini at inaf.it) View this GCN Circular online at https://gcn.nasa.gov/circulars/42173. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40242] IceCube alert 141456_888784 retraction
by GCN Circulars 08 Oct '25

08 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42172 SUBJECT: IceCube alert 141456_888784 retraction DATE: 25/10/08 23:19:08 GMT FROM: Erik Blaufuss at University of Maryland, College Park <blaufuss(a)umd.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 8 Oct 2025 at 22:35:50 UT IceCube issued an alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/141456_888784.amon) reporting the detection of a neutrino candidate event with a moderate chance of being of astrophysical origin. Upon further examination by the IceCube collaboration, the event data was incomplete and clear classification of this event is not possible. At the time of this alert, the detector was operating with several portions of the detector removed from data taking due to hardware issues. Normally, these periods of operation are excluded from generating alerts. We apologize for any confusion this error may have caused. 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/42172. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 40241] IceCube Alert 251008.94: Global MASTER-Net observations report
by GCN Circulars 08 Oct '25

08 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42171 SUBJECT: IceCube Alert 251008.94: Global MASTER-Net observations report DATE: 25/10/08 23:00:30 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-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) was pointed to the IceCube Alert 251008.94 (trigger No 888784,02h 10m 30.00s , -37d 22m 58.8s, R=0.82) errorbox 12 sec after notice time and 77 sec after trigger time at 2025-10-08 22:37:08 UT, with upper limit up to 14.9 mag. The observations began at zenith distance = 80 deg. The sun altitude is -47.1 deg. The galactic latitude b = -70 deg., longitude l = 248 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3010374 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 87 | 2025-10-08 22:37:08 | MASTER-Kislovodsk | (02h 10m 07.45s , -37d 12m 08.1s) | P- | 20 | 13.5 | 87 | 2025-10-08 22:37:08 | MASTER-Kislovodsk | (02h 10m 20.29s , -36d 49m 52.3s) | P| | 20 | 14.0 | 127 | 2025-10-08 22:37:48 | MASTER-Kislovodsk | (02h 10m 07.61s , -37d 12m 10.0s) | P- | 20 | 13.6 | 127 | 2025-10-08 22:37:48 | MASTER-Kislovodsk | (02h 10m 20.57s , -36d 49m 54.1s) | P| | 20 | 14.1 | 172 | 2025-10-08 22:38:27 | MASTER-Kislovodsk | (02h 10m 07.83s , -37d 12m 11.4s) | P- | 30 | 13.5 | 172 | 2025-10-08 22:38:27 | MASTER-Kislovodsk | (02h 10m 20.85s , -36d 49m 55.6s) | P| | 30 | 14.4 | 227 | 2025-10-08 22:39:17 | MASTER-Kislovodsk | (02h 10m 08.11s , -37d 12m 12.6s) | P- | 40 | 14.1 | 227 | 2025-10-08 22:39:17 | MASTER-Kislovodsk | (02h 10m 21.18s , -36d 49m 56.7s) | P| | 40 | 14.5 | 291 | 2025-10-08 22:40:17 | MASTER-Kislovodsk | (02h 10m 08.36s , -37d 12m 14.0s) | P- | 50 | 13.9 | 292 | 2025-10-08 22:40:17 | MASTER-Kislovodsk | (02h 10m 21.52s , -36d 49m 58.2s) | P| | 50 | 14.4 | 366 | 2025-10-08 22:41:27 | MASTER-Kislovodsk | (02h 10m 08.70s , -37d 12m 15.9s) | P- | 60 | 14.1 | 366 | 2025-10-08 22:41:27 | MASTER-Kislovodsk | (02h 10m 21.96s , -36d 49m 59.9s) | P| | 60 | 14.6 | 456 | 2025-10-08 22:42:47 | MASTER-Kislovodsk | (02h 10m 09.11s , -37d 12m 17.3s) | P- | 80 | 14.1 | 456 | 2025-10-08 22:42:47 | MASTER-Kislovodsk | (02h 10m 22.44s , -36d 50m 01.3s) | P| | 80 | 14.8 | 566 | 2025-10-08 22:44:27 | MASTER-Kislovodsk | (02h 10m 09.54s , -37d 12m 20.0s) | P- | 100 | 14.0 | 566 | 2025-10-08 22:44:27 | MASTER-Kislovodsk | (02h 10m 22.97s , -36d 50m 03.9s) | P| | 100 | 14.6 | 696 | 2025-10-08 22:46:26 | MASTER-Kislovodsk | (02h 10m 10.14s , -37d 12m 22.6s) | P- | 120 | 14.1 | 696 | 2025-10-08 22:46:27 | MASTER-Kislovodsk | (02h 10m 23.63s , -36d 50m 06.1s) | P| | 120 | 14.7 | 836 | 2025-10-08 22:48:46 | MASTER-Kislovodsk | (02h 10m 10.74s , -37d 12m 24.9s) | P- | 120 | 14.1 | 836 | 2025-10-08 22:48:46 | MASTER-Kislovodsk | (02h 10m 24.29s , -36d 50m 07.9s) | P| | 120 | 14.7 | 975 | 2025-10-08 22:51:06 | MASTER-Kislovodsk | (02h 10m 11.30s , -37d 12m 26.4s) | P- | 120 | 14.1 | 976 | 2025-10-08 22:51:06 | MASTER-Kislovodsk | (02h 10m 24.93s , -36d 50m 08.8s) | P| | 120 | 14.8 | 1115 | 2025-10-08 22:53:25 | MASTER-Kislovodsk | (02h 10m 11.90s , -37d 12m 27.9s) | P- | 120 | 14.1 | 1115 | 2025-10-08 22:53:26 | MASTER-Kislovodsk | (02h 10m 25.56s , -36d 50m 10.6s) | P| | 120 | 14.9 | The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42171. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0