TITLE: GCN CIRCULAR NUMBER: 38826 SUBJECT: GRB 250106A: SVOM detection of a long burst DATE: 25/01/06 03:58:22 GMT FROM: SVOM_group svomgroup@bao.ac.cn

D.-H. ZHAO, C. WU, W.-J. XIE (NAOC, CAS), D. Turpin (CEA), S. Guillot (IRAP), D. Götz (CEA), C-W. Wang (IHEP) report on behalf of the SVOM team.

The SVOM/ECLAIRs telescope triggered and located the long duration GRB 250106A (sb25010601) starting at 2025-01-06T02:29:19.972 UTC (Tb).   The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network.   The burst was detected by both the on-board Count-Rate Trigger (CRT) and Image Trigger (IMT) and 8 alerts were received. The best detection is obtained by IMT with a signal-to-noise ratio of 8.94 in the 8-50 keV energy band over a time window of 20.48 s starting at Tb.   The localization of the best Alert is RA, Dec = 117.152, 63.770 (J2000), which is RA(J2000) = 07h 48m 36.480s Dec(J2000)= +63d 46' 12.000' The uncertainty on this position is 8.84 arcminutes at 90% C.L., to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature.

The light curve shows one broad peak in 5-120 keV in ECLAIRs with a preliminary T90 duration of 93.64 s.

The SVOM/GRM light curve can be found here:  https://www.bursthub.cn//admin/static/svgrb250106A.png

SVOM slewed automatically on this burst. The information about MXT and VT observations will be reported later.

The Space 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.   The SVOM point of contact for this burst is: Donghua ZHAO(zhaodh@bao.ac.cn)

View this GCN Circular online at https://gcn.nasa.gov/circulars/38826. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...