{
  "bibcode": "2013GCN.15641....1X",
  "body": "D. Xu (DARK/NBI), H.-B. Niu, X. Zhang, A. Esamdin, L. Ma (XAO) report:\n\nWe observed the LAT field of GRB 131231A (Sonbas et al., GCN 15640)\nusing the 1m telescope located on Mt. Nanshan, Xinjiang, China,\nequipped with a 1.2x1.2 deg^2 CCD camera. We obtained a series of 120s\nand 300s frames at the mean time 12:40 UT on 2013-12-31 (i.e., 7.91 hr\nafter the Fermi trigger).\n\nWithin the LAT error circle (RA, Dec 10.585, -1.845 with an error\nradius of 0.149 deg, error statistical only) reported in Sonbas et al.\n(GCN 15640), no new prominent uncatalogued source is found and the\ndepth of the Nanshan image is similar to that of DSS II. Given that\nthe above LAT error is statistical only, we thus inspect that\nsurrounding region the LAT error circle and discovered a bright\nsource, not present in both DSS II and SDSS, at coordinates\n\nR.A.=00:42:21.66\nDec.=-01:39:10.79\n\nErr Radius: ~1.5 arcsec\n\nwith a magnitude of R~17.6, calibrated with nearby USNO B1 stars.\n\nFollow-up observations are encouraged to check whether the source is\nthe afterglow of the burst.",
  "circularId": 15641,
  "createdOn": 1388525964000,
  "email": "dong.dark@gmail.com",
  "subject": "GRB 131231A: Nanshan afterglow candidate",
  "submitter": "Dong Xu at DARK/NBI  <dong.dark@gmail.com>",
  "eventId": "GRB 131231A"
}