GCN Circular 38173

SVOM/ECLAIRs Commissioning Team: Hui Yang, Marius Brunet, Jean-Luc Atteia, Laurent Bouchet, Sebastien Guillot, Juliette Alaux (IRAP), Stéphane Schanne, Frédéric Chateau, Nicolas Dagoneau, Hervé Le Provost (CEA), Wenjin Xie, Donhua Zhao (NAOC), Tais Maiolino (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), Olivier Godet (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 the long GRB 241112B (sb24111201) at 2024-11-12T10:57:21 UT (Tb), which was also detected by SVOM/GRM.

The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by both the on-board Count-Rate Trigger (CRT) and Image Trigger (IMT) and 19 alerts were received. The best detection is obtained by CRT with a signal-to-noise ratio of 23.1 in the 8-50 keV energy band over a time window of 10.24 s starting at Tb. The light-curve shows two main peaks of about 10 s duration each, the first is mainly seen below 50 keV, the second below 20 keV.

The GRB localization is RA, Dec = 29.055, 9.146 (J2000).

The statistical uncertainty on this position is 3.7 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature.

SVOM performed an automatic slew to the burst.

The Space 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 APC, CEA, CNES, and IRAP.

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