{
  "bibcode": "2014GCN.15956....1X",
  "body": "D. Xu (DARK/NBI), C.-H. Bai, X. Zhang, A. Esamdin, L. Ma (XAO) report:\n\nThe previously reported afterglow candidate (Xu et al., GCN 15947) has\nbeen decaying throughout our R-band observations. Part of the\nphotometry are listed below\n\nTmid (hr)   Mag(R)  MagErr(R)\n2.06778     21.06      0.10\n1.53056     20.80      0.10\n0.49306     19.96      0.10\n\nAll magnitude are calibrated with the following three SDSS stars using\nLupton (2005) transformation:\nSDSS J135709.54+003731.9   m(r)=16.81, m(i)=16.30\nSDSS J135716.45+003657.3   m(r)=16.41, m(i)=16.10\nSDSS J135713.38+003942.0   m(r)=18.57, m(i)=18.47\n\nTogether with measurements in Klotz et al. (GCN 15952) and D'Avanzo et\nal. (GCN 15953), it shows that the optical afterglow peaks at ~0.23 hr\npost-burst and is decaying roughly as F(t) ~ t^-0.75 since ~0.5 hr\npost-burst.",
  "circularId": 15956,
  "createdOn": 1394585487000,
  "email": "dong.dark@gmail.com",
  "subject": "GRB 140311A: Nanshan afterglow decay",
  "submitter": "Dong Xu at DARK/NBI  <dong.dark@gmail.com>",
  "eventId": "GRB 140311A"
}