GCN Circular 37462

SVOM/ECLAIRs commissioning team: Stéphane Schanne, Hervé Le Provost, Nicolas Dagoneau, Frédéric Chateau (CEA), Olivier Godet, Laurent Bouchet, Sebastien Guillot, Juliette Alaux (IRAP), Frédéric Piron (LUPM), Floriane Cangemi (APC), Karine Mercier, Marie-Claire Charmeau, Stefano Crepaldi (CNES)

SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Jean-Luc Atteia (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV)

report on behalf of the SVOM team:

During the commissioning phase, the SVOM/ECLAIRs telescope triggered and located a weak GRB at 2024-09-11T20:38:48 (TtimeTb), called GRB 240911A. The burst was detected by the Count-Rate Trigger (CRT) onboard ECLAIRs. The signal to noise ratio in the reconstructed image was 6.8 in the 20-120 keV energy band during a single time window of 10.24 s starting at TimeTb. The image transmitted in real-time over the SVOM VHF network is clean and shows a point-like source.

The GRB location is RA, Dec = 351.30, 21.33 (J2000). This is about 41 degrees from the ECLAIRs optical axis. The statistical uncertainty on this position is 13 arcminutes, to which we recommend to add 10 arcminutes of systematic uncertainty.

SVOM did not slew to the burst since automated slewing is not yet enabled.

The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), French Space Agency (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES and IRAP.

The SVOM point of contact for this burst is: s.schanne AT cea.fr