[vsnet-grb-info 13117] GRB 130427A: MITSuME Akeno Optical observation(T0+8000s~)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14454
SUBJECT: GRB 130427A: MITSuME Akeno Optical observation(T0+8000s~)
DATE:    13/04/27 11:19:18 GMT
FROM:    Yoichi Yatsu at Tokyo Tech.  <yatsu at hp.phys.titech.ac.jp>

Y. Yatsu, Y. Yano,  R. Usui, Y. Tachibana, K. Ito, T. Yoshii,
S. Kurita, Y. Saito, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed GRB 130427A (Maselli et al., GCNC 14448) with an
optical tri-color (g, Rc, and Ic)  camera attached to the MITSuME
50 cm telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2013-04-27 10:06:09.60 UT (8293 sec after the
trigger).
And we found the optical counterpart reported in the twilight sky.
The measured magnitudes were listed below.

MID-MJD  T-EXP[sec]         g'                 Rc                Ic
-------------------------------------------------------------------------------------------
 56409.4231929  360  15.66+/-0.10  15.03+/-0.07  14.71+/-0.09
-------------------------------------------------------------------------------------------
T-EXP: Total Exposure time [sec]
(The photon flux were calibrated against GSC2.3 catalog.)