GCN Circular 43613

M. Pillas (IAP), M. Dennefeld (IAP), M. Brunet (IRAP), S. Guillot (IRAP), C. Pellouin (IAP), report on behalf of the SVOM mission team:

At 2026-02-04T14:48:49 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260204A (SVOM burst-id sb26020403).

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 6 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 10.87 in the [5-20] keV energy band over a time window of 40.96 seconds starting at 2026-02-04T14:48:28.

The localization of the best alert is R.A., Dec. 205.1185, 2.0200 degrees:
R.A. (J2000) = 13h40m28.44s
Dec. (J2000) = 2d01m12.14s
with a 90% confidence level (C.L.) radius of 7.36 arcmin (including systematic error of 2 arcmin added in quadrature).

SVOM slewed to the burst.

No X-ray observation could be performed by SVOM/MXT for the time being, due to Earth occultation.

SVOM/VT observations will be reported in 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 Marion Pillas: marion.pillas@iap.fr.
Please contact the BA by email if you require additional information.