GCN Circular 40415

Y.H. Cheng (SWIFAR,YNU), B.-T. Wang (YNAO, CAS), W. J. Xie, D. H. ZHAO (NAO, CAS) on behalf of the SVOM mission team.

SVOM/ECLAIRs triggered and located GRB 250510A (SVOM burst-id sb25051002) at 2025-05-10T04:38:52.34 UTC (Tb). 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 Count-Rate Trigger (CRT), which produced a sequence of 1 alert. CRT provided the alert with the best signal-to-noise-ratio (SNR) of 7.16 in the [20-120] keV energy band over a time window of 10.20 seconds starting at Tb.

The localization of the best alert is R.A., Dec. 284.17, 18.37 degrees:
R.A. (J2000) = 18h56m41.69s
Dec. (J2000) = 18d22m20.68s
with a 90% confidence level (C.L.) radius of 10.94 arcmin (including systematic error of 2 arcmin added in quadrature).

Due to the trigger SNR less than the slew threshold, no immediate slew was performed on this burst. 

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 Yehao Cheng: yhcheng@mail.ynu.edu.cn.
Please contact the BA by email if you require additional information regarding the SVOM follow-up of this burst.