{
  "body": "J. An, X. Liu, S.Q. Jiang, S.Y. Fu, T.H. Lu, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:\n\nWe observed the field of GRB 231215A detected by Swift (D'Avanzo et al., GCN 35343) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 11:51:08 UT on 2023-12-15, i.e., 2.06 hr after the BAT trigger. A series of 90, 120, 200 s frames without any filter have been obtained and observations are ongoing.\n\nPreliminary analysis of the initial frames shows that the previously reported optical afterglow (e.g., Pankov et al., GCN 35349; Sasada et al., GCN 35351) has decayed to m(r) = 18.3 +/- 0.1 mag at 2.19 hr post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter and the magnitude is not corrected for Galactic extinction.\n\n\n",
  "eventId": "GRB 231215A",
  "submittedHow": "email",
  "submitter": "Dong Xu at NAOC/CAS <dxu@nao.cas.cn>",
  "circularId": 35353,
  "createdOn": 1702650740424,
  "bibcode": "2023GCN.35353....1A",
  "subject": "GRB 231215A : Nanshan/HMT optical observations"
}