TITLE:   GCN CIRCULAR
NUMBER:  43458
SUBJECT: GRB 251208D: SVOM/ECLAIRs refined analysis
DATE:    26/01/19 20:59:19 GMT
FROM:    SVOM_group <svomgroup@bao.ac.cn>

H. Yang, O. Godet (IRAP), F. Daigne (IAP), Z.-Y. Lin, F. Cangemi (APC)


Using the event-by-event data downloaded through the X-band ground station, we report further analysis of ECLAIRs observations of the possible faint burst GRB 251208D (SVOM burst-id sb25120806, GCN 43032) detected at T0 = 2025-12-08T16:51:43 UT. 

The burst that triggered ECLAIRs shows a featureless light curve, and is detected from T0-82 s to T0  in the 8-120 keV energy band. 

The time-averaged spectrum from T0-82 s to T0 in the 8-120 keV is well fitted by a power-law model with a photon index of 1.8+/-0.4 and a corresponding 4-120 keV fluence of (1.1+/-0.3)e-6 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. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC.

The SVOM/ECLAIRs point of contact for this burst is: Hui Yang (IRAP) (hui.yang@irap.omp.eu).