GCN Circular 46292
Subject
GRB 261108A: SVOM/ECLAIRs refined analysis
Event
Date
2026-11-15T10:59:08Z (4 hours ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
O. Godet (IRAP), N. Dagoneau (CEA), W. Xie (NAOC), X. Feng (GXU) report on behalf of the SVOM/ECLAIRs team
Using the event-by-event data downloaded through the X-band ground station, we report further analysis of SVOM/ECLAIRs observations of GRB 261108A (SVOM burst-id sb26110802 – GCN 46186, trigger time T0 = 2026-11-08T01:13:20 UTC), which was also detected by Fermi/GBM (GCN 46185, Trigg 2025, GCN 46197).
The burst that triggered ECLAIRs onboard shows a main peak lightcurve with a precursor between T0-20 s and T0-18 s. The burst duration is T90 = 8.58 -1.12/+0.88 s in the 4-120 keV energy band.
The time-averaged spectrum from T0-1.77 s to T0+6.84 s in the 5-120 keV energy range is best fitted by a cutoff powerlaw model with a photon index alpha = -1.08 ± 0.17 and a parametrized Epeak-value of 42.3 ± 15.8 keV. With this model, the 4-120 keV fluence is (4.8 ± 2.1)e-7 erg/cm^2 and the 4-120 keV photon flux is 2.1 ± 0.6 ph/cm^2/s.
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. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC.
The SVOM/ECLAIRs point of contact for this burst is: Olivier Godet (IRAP) (olivier.godet at utoulouse.fr)