[vsnet-grb-info 2559] GRB051117B: optical observation

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4396
SUBJECT: GRB051117B: optical observation
DATE:    05/12/27 16:02:46 GMT
FROM:    Daisaku Nogami at Kyoto U  <nogami at kwasan.kyoto-u.ac.jp>

D. Nogami, T. Kawamura, J. Kuriyama, K. Sugiyasu, K. Kubota
(Kyoto Univ.), K. Yanagisawa (Okayama Astrophys. Obs.),
S. Kouzuma, H. Yamaoka (Kyushu Univ.), and N. Kawai (Tokyo
Inst. of Tech.) report:

We observed the field of GRB051117B (Band et al., GCN 4281)
with a 50-cm telescope (MITSuME) at the Okayama Astrophysical
Observatory, using a three-color (g', Rc, and Ic) CCD imager.
The observations started at 14:16:22 (UT), about 54 min after
the trigger time, and ended at 16:36:46 (UT).  The exposure
time was 60 sec, and we obtained 110 images in each band.

We could not find any afterglow candidate around the error
box of GRB051117B (GCN 4281).  The 3-sigma upper limits in
the stacked images of each band are 19.2 mag, 19.2 mag, and
19.5 mag in the g', Rc, and Ic band, respectively.  These
magnitudes were calibrated with the catalogs of Tycho (VT),
USNO A2.0 (R), and USNO B1.0 for g', Rc, and Ic, respectively.