GCN Circular 44823
Subject
GRB 260604C: SVOM detection of a long burst
Event
Date
2026-06-04T20:43:09Z (a day ago)
From
Diego Gotz at CEA <diego.gotz@cea.fr>
Via
Web form
D. Gotz, D. Adrien, N. Dagoneau, S. Bisero (CEA Saclay) report on behalf of the SVOM mission team:
At 2026-06-04T20:21:59 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260604C (SVOM burst-id sb26060404).
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 Image Trigger (IMT), which produced a sequence of 4 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 8.23 in the [5-20] keV energy band over a time window of 163.84 seconds starting at 2026-06-04T20:19:56 UTC.
The localization of the best alert is R.A., Dec. 224.3461, 28.6558 degrees:
R.A. (J2000) = 14h57m23s
Dec. (J2000) = 28d39m20s
with a 90% confidence level (C.L.) radius of 9.6 arcmin (including systematic error of 2 arcmin added in quadrature).
This position is compatible with the GRB detected by Fermi/GBM GCN 44822 .
SVOM slewed to the burst position.
No X-ray observation could be performed by SVOM/MXT for the time being.
Optical observations by VT will be published in a further 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 Sofia Bisero: sofia.bisero@cea.fr.
Please contact the BA by email if you require additional information.