TITLE: GCN CIRCULAR NUMBER: 41726 SUBJECT: GRB 250901A - SVOM/ECLAIRs refined analysis DATE: 25/09/05 13:34:45 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> Tais Maiolino (LUPM), Frédéric Piron (LUPM), Claire Guépin-Detrigne (LUPM) Using the event-by-event data downloaded through the X-band ground station, we report further analysis of ECLAIRs observations of GRB 250901A (SVOM burst-id sb25090101). The burst that triggered ECLAIRs (GCN #41634) consists of a single pulse structure with a duration of T90 = 16 +1/-3 s in the 4-120 keV energy band. The time-averaged spectrum from T0-8 s to T0+10 s (T0 = 2025-09-01T18:14:22.916) in the energy range 5-120 keV is best fitted by a power-law model with photon index -1.15 +/- 0.09. With this model, the 4-120 keV fluence is (1.4 +/- 0.1) e-06 erg/cm^2. All the quoted errors are at the 68% confidence level. We note that the calibration of SVOM/ECLAIRs is undergoing thus these results are preliminary 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. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. The SVOM/ECLAIRs point of contact for this burst is: Tais Maiolino (LUPM) (tais.maiolino at lupm.in2p3.fr) View this GCN Circular online at https://gcn.nasa.gov/circulars/41726. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...