[vsnet-grb-info 17377] GRB 151228B: MITSuME Akeno optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18758
SUBJECT: GRB 151228B: MITSuME Akeno optical upper limits
DATE:    15/12/29 21:44:48 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac at m.titech.ac.jp>

Y.Muraki, T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana,
Y.Yano, S.Harita, Y. Yatsu, and N. Kawai (Tokyo Tech)

report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 151228B (A. Y. Lien et al., GCN Circular #18739) 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 2015-12-29 09:55:19 UT (~11.1 h after the burst).
We did not find any new point source within Swift/XRT circle in all three bands.

We obtained following limits for the magnitudes.

T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
-------------------------------------------------------------
40085  10:37:06  2507  > 20.9  > 20.6  > 19.6
-------------------------------------------------------------
T0+ : Elapsed time after the burst 
T-EXP: Total Exposure time 
We used GSC2.3 catalog for flux calibration.