{
  "bibcode": "2015GCN.17339....1X",
  "body": "L. P. Xin,   X. F. Wang,  J. Y. Wei,  Y. L. Qiu, J. S. Deng, \r\nJ. Wang,  X. H. Han and C. Wu on behalf of EAFON report:\r\n \r\nWe began to observe GRB 150120B (D'Elia et al., GCN 17314)  \r\nwith Xinglong  0.8-m TNT telescope at 2015-01-20, 10:56:50 (UT),\r\nabout 3.58 hours after the burst.\r\n \r\nIn the 15*300sec coadded R-bamd image, the optical counterpart\r\n(D. A. Perley GCN 17315; Guidorzi et al., GCN 17316;  Wiseman et al., 17336; \r\nPandey GCN 17337) was detected with a brightness of  \r\nR=21.3+/-0.2 mag at the mid-time of 4.2 hours  after the burst, \r\ncalibrated by the nearby USNO B1.0 R2 mag.\r\n \r\nThe message may be cited.",
  "circularId": 17339,
  "createdOn": 1421849251000,
  "email": "xlp@bao.ac.cn",
  "subject": "GRB150120B: Xinglong TNT optical observation",
  "submitter": "L.P. Xin at NAOC  <xlp@bao.ac.cn>",
  "eventId": "GRB 150120B"
}