TITLE: GCN CIRCULAR NUMBER: 38306 SUBJECT: GRB 241113B: SVOM/VT optical afterglow observations DATE: 24/11/25 12:03:27 GMT FROM: Huali Li at at NAOC, SVOM <lhl@nao.cas.cn> SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO), W. K. Zheng (UCB), Z. Q. Wang (GXU) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), 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), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: VT started to observe GRB 241113B (SVOM/ECLAIRs, Dagoneau et al., GCN 38196; SVOM/GRM, Liu et al., GCN 38212; EP/WXT, Liu et al., GCN 38214; Du et al., GCN 38252) in ToO mode from 2024-11-13T14:23:24 UT, about 3.0 hours after the burst. The VT conducted observations in VT_B band (400-650nm) and VT_R band (650-1000nm) simultaneously. The afterglow (Zheng et al., GCN 38232) was detected in both bands with the brightness of VT_B = 22.5 +/- 0.1 mag and VT_R = 21.95+/-0.06 mag in AB magnitude at the midtime of 3.87 hours after the burst. The exposure time of images in VT_R and VT_B are 1470 sec and 1620 sec respectively. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (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. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/38306. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...