TITLE: GCN CIRCULAR NUMBER: 44181 SUBJECT: GRB 260402A: SVOM detection of a burst DATE: 26/04/02 10:51:18 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> W. Tan, R. Li (IHEP), M. Brunet, O. Godet (IRAP), D. Gotz (CEA), report on behalf of the SVOM mission team: At 2026-04-02T10:30:17 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260402A (SVOM burst-id sb26040203). 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 17 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 18.74 in the [5-20] keV energy band over a time window of 10.20 seconds starting at 2026-04-02T10:30:17. The localization of the best alert is R.A., Dec. 170.982, 63.622 degrees: R.A. (J2000) = 11h23m55s Dec. (J2000) = 63d37m18s with a 90% confidence level (C.L.) radius of 4.57 arcmin (including systematic error of 2 arcmin added in quadrature). The SVOM/ECLAIRs light curve showed a broad peak structure with a T90 duration of 15.17 (-1.27 / +5.86) s in the 5-120 keV energy band. This burst was also detected by SVOM/GRM with a significance of 7.20. SVOM slewed to the burst. No prompt X-ray observation could be performed by SVOM/MXT for the time being. VT began observing the field after the slew. The analysis of the data will be published in a 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 Wenjun Tan: tanwj at ihep.ac.cn. Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/44181. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...