{
  "bibcode": "2007GCN..6965....1X",
  "body": "L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,\nJ. Wang, Y. Urata and W.K. Zheng on behalf of EAFON report:\n\nWe observed the field of GRB071018 (Krim et al. GCN 6932) with the TNT 0.8m \ntelescope at Xinglong Observatory for the 2nd epoch, Observation was started \nfrom 19:12:25 UT, 19th Oct. 1.494 days after the burst. A series of R-band \nimages were obtained. In our 14*600s combined images we can still find the \ntwo sources of our last observation (Xin et al. GCN 6936). \n\nThe estimated bringhtness of the source #1 and #2 (Xin et al. GCN6936) \nderieved from USNO-B1.0 R2 magnitude were R=20.67+-0.318 and R=20.72+-0.36 \nrespectively. The magnitude of source #1 was consistent with the value \nreported by SARA (Updike et al. GCN 6944) and Mercator (Alberto \nCastro-Tirado, GCN6947). but bringter than the value of our last observation \n(Xin et al. GCN6936), So the source #1 only maybe a avariable source as \nreported (Adria, GCN 6944), and the source $2 also might not be the OT of the \nburst.\n\nAt the locations of the XRT error circles of source 1 and source 2 (GCN 6943, \nBeardmore et al.), We found no new optical source to the 3sigma limit  \nmagnitude R=21.2 . \n\nWe also checked the combined image (Xin et al. GCN6936) obtained on 18th Oct, \nNo new source was found at the location of XRT source 2 to 3-sigma limit \nmagnitude R=21.5. The location of XRT source 1 was outside the field of view \nof the combined image.\n\nThis massage may be cited.",
  "circularId": 6965,
  "createdOn": 1192991091000,
  "email": "xlp@bao.ac.cn",
  "subject": "GRB071018: 2nd epoch obsevations of Xinglong TNT",
  "submitter": "L.P. Xin at NAOC  <xlp@bao.ac.cn>",
  "eventId": "GRB 071018"
}