{
  "bibcode": "2003GCN..2496....1S",
  "body": "R. Sato and N. Kawai (Tokyo Tech) report:\n\n\"We have observed the field covering the entire SXC error box of \nGRB 031220 (HETE trigger 2976; trigger time 03:29:56.7 UT) with the\nunfiltered CCD camera on the 30-cm telescope at Tokyo Tech, beginning\nat 09:23:19 UT on Dec. 20.  After co-adding a set of 10 images of 10\nsec exposures, comparison with the USNO A2.0 catalog revealed no new\nsources in the SXC error box.  Furthermore, visual inspection of the\nimages revealed no obvious new source compared with the DSS-2 Red to\nan approximate limiting magnitude of 16.5.\"",
  "circularId": 2496,
  "createdOn": 1071978775000,
  "email": "nkawai@hp.phys.titech.ac.jp",
  "subject": "GRB 031220: Optical observation at Tokyo Tech",
  "submitter": "Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>",
  "eventId": "GRB 031220"
}