[vsnet-grb-info 17146] GRB 151027A: MITSuME Akeno Optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18491
SUBJECT: GRB 151027A: MITSuME Akeno Optical observation 
DATE:    15/10/27 16:23:13 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac at m.titech.ac.jp>

Y. Yano, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi,
S. Kurita, Y. Ono, T. Fujiwara, S. Harita, Y. Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 151027A (A. Maselli et al., GCN Circular #18478) with the 
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2015-10-27 09:13:52 UT ( 5.25 h after the burst).
We detected the previously reported optical afterglow of GRB 151027A 
(WeiKang Zheng et al., GCN Circular #18479) in the g',Rc and Ic band.

The measured magnitudes are listed below.

T0+[sec] MID-UT  T-EXP[sec]       g'                   Rc                 Ic
------------------------------------------------------------------------------------------------------------------
 18928     09:34:24      2220     16.72+/-0.06 15.62+/-0.05 16.00+/-0.04
------------------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst 
T-EXP: Total Exposure time 
We used GSC2.3 catalog for flux calibration.