GCN Circular 46030

Hatsune Goto (RIKEN/CEA), Clara Plasse (HKU), Wenjin Xie, Chao WU (NAOC), Chenwei Wang (IHEP) report on behalf of the SVOM mission team:

At 2026-10-26T06:09:37 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 261026A (SVOM burst-id sb26102601).

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 8 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 11.10 in the [5-20] keV energy band over a time window of 20.40 seconds starting at 2026-10-26T06:09:27.

The localization of the best alert is R.A., Dec. 337.3314, 27.0485 degrees:
R.A. (J2000) = 22h29m19.52s
Dec. (J2000) = 27d02m54.66s
 with a 90% confidence level (C.L.) radius of 7.22 arcmin (including systematic error of 2 arcmin added in quadrature).

This burst was also detected by SVOM/GRM with a significance of 11.20.
SVOM slewed to the burst.

SVOM/MXT and VT began observing the field after the slew. The analysis of the data will be published in future circulars.

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 Chao WU: cwu@nao.cas.cn. Please contact the BA by email if you require additional information.