TITLE: GCN CIRCULAR NUMBER: 38791 SUBJECT: GRB 250103A: SVOM/C-GFT optical upper limit DATE: 25/01/03 13:07:47 GMT FROM: Chao Wu at NAOC <cwu@nao.cas.cn> SVOM/C-GFT team: Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC),Yulei Qiu (NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC) 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) We observed the field of GRB 250103A (Wang et al., GCN 38787) starting at 2025-01-03T09:57:26, ~83 sec after the burst trigger with C-GFT. A series of g,r,i band images were obtained with exposure time of 10s for each frame. No any uncataloged sources were detected within the SVOM/ECLAIRs error circle (Wang et al., GCN 38787) compared to PanSTARRS1 catalog. 3 sigma limit magnitude of i=19.4 was derived at the middle time of ~120 s after the trigger. We thank the observation assistant Guangsheng Zhang and Yinhuai Hao at Jilin observatory for their excellent support. Chinese Ground Follow-up Telescope of SVOM mission is located at Jilin, Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope. View this GCN Circular online at https://gcn.nasa.gov/circulars/38791. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...