TITLE: GCN CIRCULAR NUMBER: 39041 SUBJECT: GRB 250127A: SVOM detection of a long burst DATE: 25/01/27 06:17:14 GMT FROM: Stéphane Schanne at CEA Paris-Saclay/IRFU <s.schanne@cea.fr> C. Wu, D.-H. Zhao, W.-J. Xie (NAOC), S. Schanne (CEA), C.-W. Wang (IHEP), D. Götz (CEA) report on behalf of the SVOM team: The SVOM/ECLAIRs telescope triggered and located the long duration GRB 250127A (sb25012701) starting at 2025-01-27T05:04:46 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 12 alerts were received. The best detection is obtained by IMT with a signal-to-noise ratio of 17.45 in the 8-120 keV energy band over a time window of 40.96 s starting at Tb. In the real-time light-curve the burst is well seen in the 5-50 keV band and not above. The localization of the best Alert is RA, Dec = 169.589, 3.346 (J2000). The uncertainty on this position is 4.8 arcminutes at 90% C.L. which includes 2 arcminutes of systematic uncertainty in quadrature. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250127A.png SVOM performed an automatic slew on this burst, MXT and VT results 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/39041. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...