{
  "bibcode": "2020GCN.29166....1X",
  "body": "L. P. Xin(NAOC),  L. H. Li(NAOC), X. H. Han(NAOC), J. Y. Wei(NAOC),  J. Wang(GXU),  \nC. Wu(NAOC),  X. G. Wang(GXU), E. W. Liang (GXU), Y. L. Qiu(NAOC), and J. S. Deng(NAOC) report:\n\nWe began to observe GRB 201223A (Gropp et al., GCN #29158, \nWood et al., GCN #29161) with Xinglong GWAC-F60A telescope, China, \nat 17:59:10.1 (UT), 23th. Dec. 2020, about 44 sec after the burst.\n\nA series of  R, I, and B band images were obtained.\nThe optical afterglow reported by (Lipunov et al., GCN #29157; Gropp et\nal., GCN #29158; Zhu et al., GCN #29159; Hu et al.���GCN #29160;\nHosokawa et al., GCN #29164; Filipp Dmitrievich Romanov GCN #29165)\nwas clear detected in our images. \n\nThe brightness is fading from 15.0 mag to 18.8 mag  in R band\nduring about 100 sec to 10000 sec after the burst. \n \nThe R-band brightness is calibrated to the USNO B1.0 catalog,\n(RA=08:50:21.447, DEC=+71:12:12.80, J2000, R2=9.92)\n\nMore analysis are still continuing.\n\nThe message may be cited.",
  "circularId": 29166,
  "createdOn": 1608792976000,
  "email": "xlp@nao.cas.cn",
  "subject": "GRB 201223A: GWAC-F60A optical afterglow observations",
  "submitter": "Liping Xin at NAOC, SVOM  <xlp@nao.cas.cn>",
  "eventId": "GRB 201223A"
}