TITLE: GCN CIRCULAR NUMBER: 43001 SUBJECT: GRB 251203C: SVOM/ECLAIRs refined analysis DATE: 25/12/05 14:17:52 GMT FROM: SVOM_group N. Dagoneau (CEA), M. Brunet, N. A. Webb (IRAP) Using the event-by-event data downloaded through the X-band ground station, we report further analysis of ECLAIRs observations of GRB 251203C (SVOM burst-id sb25120305). The burst that triggered ECLAIRs onboard (GCN 42976) consists of a multiple peaks lightcurve with a duration of T90 = 13.0 -4.7/+1.6 s in the 4-120 keV energy band. The time-averaged spectrum (from T0-3.59s to T0+9.49s) in the energy range 5-120 keV is best fit by a simple power-law model with a photon index -1.98 -0.17/+0.18. The total fluence in the 4-120 keV band is (3.63 -0.59/+0.27)e-7 erg/cm^2. All the quoted errors are at the 68% confidence level. 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.