TITLE: GCN CIRCULAR NUMBER: 38450 SUBJECT: GRB 241206B: SVOM/ECLAIRs detection of a long soft transient DATE: 24/12/06 16:21:14 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> SVOM/ECLAIRs Commissioning Team: Andrea Saccardi, Dylan Adrien, Nicolas Dagoneau, Stéphane Schanne, Frédéric Chateau, Hervé Le Provost (CEA), Jean-Luc Atteia, Laurent Bouchet, Marius Brunet, Sebastien Guillot, Juliette Alaux, Hui Yang (IRAP), Wenjin Xie, Donghua Zhao (NAOC), Alexis Coleiro (APC), Tais Maiolino (LUPM), 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 duration soft transient called GRB 241206B (sb24120602) at 2024-12-06T15:08:48 UT (Tb). The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by the Image Trigger (IMT) only and 2 alerts were received. The best detection is obtained with a signal-to-noise ratio of 9.3 in the 5-8 keV energy band over a time window of 1310.72 s starting at Tb. The localization of the best Alert is RA, Dec = 300.202, 65.182 (J2000). The statistical uncertainty on this position is 9.1 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature. SVOM did not slew on this burst. We notice that QSO B1959+650 is within the error box. 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: andrea.saccardi@cea.fr View this GCN Circular online at https://gcn.nasa.gov/circulars/38450. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...