[vsnet-grb-info 8225] GRB 090807: MITSuME optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9752
SUBJECT: GRB 090807: MITSuME optical upper limit
DATE:    09/08/08 07:58:00 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida at oao.nao.ac.jp>

M. Yoshida, D. Kuroda, K. Yanagisawa, Y. Shimizu, S. Nagayama,
H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf
of the MITSuME collaboration:

We observed the field of GRB 090807 (Cannizzo et al. GCN 9746)
with optical three color (g', Rc and Ic) CCD camera attached to
the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2009-08-07 15:03:35 UT (3m 8s after
the burst). We did not find any point source in the error circle
of the XRT position reported by Beardmore et al. (GCN 9748) in
all the three bands.

Three sigma upper limits of the OT are listed below. We used USNO
B1 catalog for flux calibration.

PDAY        MID-UT   T-EXP     g'     Rc     Ic
---------------------------------------------------
0.00589   15:08:56   540.0   >18.3  >18.5  >18.2
0.04169   16:00:30  4860.0   >18.9  >19.1  >18.7
---------------------------------------------------