{
  "body": "SVOM/C-GFT team: Zhe Kang (CHO), Chao WU (NAOC), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC)\n\nSVOM 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)\n\n\nWe observed the field of GRB 241212A (Zhang et. al, GCN 38541; Fermi team GCN 38540;Joshi et al. GCN 38544) starting at 2024-12-12T09:22:45 UT, ~53 sec after the burst trigger with C-GFT. A series of g, r and i band images were obtained with exposure time of 10s. Due to bad observation condition(not good weather, low altitude and ~13.8 deg to the moon), the optical counterpart reported by Qiu et al. (GCN 38545) was not detected in the images. The upper limit at early phase are,\n\n(T-T0)_mid(sec)      limiting_mag(3sigma)   \n-------------------------------------\n   58                  15.80\n   91                  16.80     \n\n          \nThe photometry was calibrated with nearby stars in ucac4.\n\nWe thank the observation assistant Bowen Li and Chunlei Guo at Jilin observatory for their excellent support.\n\nChinese 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.",
  "subject": "GRB 241212A : SVOM/C-GFT optical upper limit at early phase",
  "submitter": "Chao Wu at NAOC <cwu@nao.cas.cn>",
  "eventId": "GRB 241212A",
  "circularId": 38546,
  "submittedHow": "web",
  "bibcode": "2024GCN.38546....1S",
  "createdOn": 1734051516401,
  "format": "text/plain"
}