TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2496
SUBJECT: GRB 031220: Optical observation at Tokyo Tech
DATE:    03/12/21 03:52:55 GMT
FROM:    Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>

R. Sato and N. Kawai (Tokyo Tech) report:

"We have observed the field covering the entire SXC error box of 
GRB 031220 (HETE trigger 2976; trigger time 03:29:56.7 UT) with the
unfiltered CCD camera on the 30-cm telescope at Tokyo Tech, beginning
at 09:23:19 UT on Dec. 20.  After co-adding a set of 10 images of 10
sec exposures, comparison with the USNO A2.0 catalog revealed no new
sources in the SXC error box.  Furthermore, visual inspection of the
images revealed no obvious new source compared with the DSS-2 Red to
an approximate limiting magnitude of 16.5."