{
  "bibcode": "2025GCN.39935....1W",
  "circularId": 39935,
  "eventId": "GRB 250329B",
  "subject": "GRB 250329B: SVOM/C-GFT optical upper limit",
  "createdOn": 1743290861655,
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "submittedHow": "web",
  "body": "Chao WU (NAOC), W.J. Xie (NAOC), Y.H. Cheng (SWIFAR, YNU), B.T. Wang (YNAO, CAS), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC), Yulei, Qiu(NAOC), Jing Wang(NAOC), Jianyan Wei (NAOC) report on behalf of the SVOM/C-GFT team:\n\nWe observed the field of GRB 250329B detected by SVOM/ECLAIRs (sb25032902) with C-GFT. Our observations were started on 2025-03-29T12:50:31 UTC, ~40.20 mins after the trigger. \n\nNo any source was detected in our stacked image within the source error circle of the X-ray Swift/XRT (source #1: https://www.swift.ac.uk/SVOM/SVOM_FIELD00008/ ).\n\nThe limiting magnitude(3 sigma) in i band is 19.80 mag at the middle time of 41.95 minutes after the burst.\n\nThe photometry was calibrated  with UCAC4 catalog. This result is consistent with the reports (Xin et al., GCN 39926, Chen et al., GCN 39929, and Xin et al., GCN 39931).\n\nWe thank the observation assistants Yinhuai Hao and Bowen Li  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.",
  "format": "text/plain"
}