TITLE: GCN CIRCULAR NUMBER: 40313 SUBJECT: GRB 250502A: SVOM detection of a burst DATE: 25/05/02 09:51:06 GMT FROM: SVOM_group Y. Wang (PMO, CAS), J.X Cao (GXU), L. Bouchet, M. Brunet (IRAP), C. Plasse (CEA) on behalf of the SVOM mission team. SVOM/ECLAIRs triggered on the gamma-ray burst GRB 250502A (SVOM burst-id sb25050205) starting at 2025-05-02T08:46:27 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 the Image Trigger (IMT). A sequence of 3 alerts was produced. IMT provided the alert with the best signal-to-noise-ratio (SNR) of 8.94 in the 8-50 keV energy band over a time window of 40.96 seconds starting at Tb. The localization of the best alert is R.A., Dec. 206.479, -10.643 degrees: R.A. (J2000) = 13h45m54.84s Dec. (J2000) = -10h38m34.49a with a 90% confidence level (C.L.) radius of 8.84 arcmin (including systematic error of 2 arcmin added in quadrature). SVOM slewed to the burst. MXT began observing the field after the slew. The analysis of MXT data will be published in a future circular. VT began observing the field after the slew. The analysis of the recorded images will be published in a future circular gathering information on the follow-up of the SVOM optical instruments. 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. The Burst Advocate (BA) on shift for this burst is Y. Wang: wangyun@pmo.ac.cn. Please contact the BA by email if you require additional information regarding the SVOM follow-up of this burst.