GCN Circular 46186
Subject
GRB 261108A: SVOM detection of a burst
Event
Date
2026-11-08T01:54:22Z (12 hours ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
Wenjin Xie (NAOC), Xin Feng (GXU), Youdong Hu (GXU), Clara Plasse (HKU), Hatsune Goto (RIKEN/CEA) report on behalf of the SVOM mission team:
At 2026-11-08T01:13:20 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 261108A (SVOM burst-id sb26110802). The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.
The burst was detected both by the Count-Rate Trigger (CRT) and the Image Trigger (IMT), which produced a sequence of 18 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 17.68 in the [8-50] keV energy band over a time window of 10.20 seconds starting at 2026-11-08T01:13:17.
The localization of the best alert is R.A., Dec. 336.5157, -20.2077 degrees:
R.A. (J2000) = 22h26m03.78s
Dec. (J2000) = -20d12m27.78s
with a 90% confidence level (C.L.) radius of 4.79 arcmin (including systematic error of 2 arcmin added in quadrature).
This burst was also detected by SVOM/GRM with a significance of 17.30. The SVOM/GRM light curve showed a single peak structure with a T90 duration of about 9.33 (-1.42 +1.95) s.
This burst is consistent in time and position with Fermi/GBM detection at 01:13:19 UTC (GCN #46185).
SVOM slewed to the burst. SVOM/MXT and VT started observation. The analysis of the data will be published in a future circular.
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 Clara Plasse: cplasse@hku.hk.
Please contact the BA by email if you require additional information.