{
  "bibcode": "2009GCN.10080....1X",
  "body": "L.P. Xin, X.F. Wang, J. Wang, Y.L. Qiu, J.Y. Wei, \nW.K. Zheng, J.S. Deng, and C. Wu, J.Y. Hu \non behalf of EAFON report:\n\nWe observed the optical afterglow of GRB 091020 \n(e.g. Racusin et al., GCN 10048; Gorbovskoy et al., \nGCN 10052; Perley GCN 10060) with Xinglong TNT \ntelescope from  Oct. 22, 20:27:52(UT),1.952 days \nafter the burst. The optical afterglow (Gorbovskoy \net al., GCN 10052; Perley GCN 10060) was not detected \nin our combined image with a duration of 7*600 sec.\nThe upper limit is estimated to be R~21.4 mag \nfrom  USNO-B1.0 R2 magnitude, at the mean time of \n1.974 days since the trigger.\n\nThis message may be cited.\n\nFor more information about Xinglong GRBs Follow-up \nobservations, please visit the web-site:\nhttp://www.xinglong-naoc.org/grb/",
  "circularId": 10080,
  "createdOn": 1256560307000,
  "email": "xlp@bao.ac.cn",
  "subject": "GRB 091020 : Xinglong TNT upper limit",
  "submitter": "L.P. Xin at NAOC  <xlp@bao.ac.cn>",
  "eventId": "GRB 091020"
}