[vsnet-grb-info 21309] GRB 181103A: MITSuME Okayama optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23408
SUBJECT: GRB 181103A: MITSuME Okayama optical upper limits
DATE:    18/11/05 04:35:48 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata at u.phys.nagoya-u.ac.jp>

K. L. Murata, R. Itoh, Y. Tachibana, S. Harita, K. Morita, K. Shiraishi, K.
Iida, M. Oeda, M. Niwano, R. Adachi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 181103A (A. Tohuvavohu  et
al., GCN Circular #23402) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of  Okayama Astrophysical
Observatory, Japan.

The observation started on 19:38:58 UT. We did not find any new point
source within enhanced XRT circle (P.A. Evans et al., GCN Circular #23403)
in all three bands. We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
15.352       20:15:29          3240      >18.5     >18.0     >17.5
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.