{
  "bibcode": "2007GCN..6962....1X",
  "body": "L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,\nJ. Wang and W.K. Zheng on behalf of EAFON report:\n \nWe have imaged the field of GRB 071021 (T. Sakamoto, et al.;\nGCN 6958) with the TNT 0.8m telescope at Xinglong\nObservatory started from  09:55:06.5 UT, 813.8880 after\nthe burst.  A series of White and R band images were\nobtained, no new source was found in our combined\nimage within the error region of the XRT\n(T. Sakamoto, et al.; GCN 6958) and the location reported \nby C. Guidorzi et al (GCN 6959)\n\nThe 3-sigma limit derived from\nUSNO-B1.0 R2 mag were: \n------------------------------------\nBand     Mid time     Exp time  Limit Mag\n \nWhite   0.72 hours     40*20s     20.32 \nR      1.38 hours      12*300s    20.85\nR      3.25 hours      16*600s    21.69\n  \nThis message may be cited.\n\n[GCN OPS NOTE(21oct07): Per author's request, the names for the 3 references\nwere changed T. Sakamoto, T. Sakamoto, and C. Guidorzi.]",
  "circularId": 6962,
  "createdOn": 1192987064000,
  "email": "xlp@bao.ac.cn",
  "subject": "GRB 071021: Xinglong TNT optical Upper Limit",
  "submitter": "L.P. Xin at NAOC  <xlp@bao.ac.cn>",
  "eventId": "GRB 071021"
}