GCN Circular 46200

Li Zhang (IHEP), Hatsune Goto (CEA/RIKEN), Wenjin Xie (NAOC), Wenlong Zhang (PMO), Wenjun Tan (PKU),  report on behalf of the SVOM mission team:
At 2026-11-08T23:52:36 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 261108D (SVOM burst-id sb26110813).

The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.

The burst was only detected by the Count-Rate Trigger (CRT), which produced a sequence of 4 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 7.57 in the [5-20] keV energy band over a time window of 5.10 seconds starting at 2026-11-08T23:52:28.

The localization of the best alert is R.A., Dec. 170.8495, -77.4870 degrees:
R.A. (J2000) = 11h23m23.89s
Dec. (J2000) = -77d29m13.07s
 with a 90% confidence level (C.L.) radius of 10.37 arcmin (including systematic error of 2 arcmin added in quadrature).

Due to the sun angle constraint, no immediate slew was performed on this burst.
No X-ray observation could be performed by SVOM/MXT for the time being.No optical observation could be performed by SVOM/VT for the time being.

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 Wenjun Tan: tanwj@ihep.ac.cn.
Please contact the BA by email if you require additional information.