[vsnet-grb-info 16434] GRB 150413A: MITSuME Akeno Optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17715
SUBJECT: GRB 150413A: MITSuME Akeno Optical observation
DATE:    15/04/17 13:17:03 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac at m.titech.ac.jp>

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

We observed the field of GRB 150413A (C. B. Markwardt et al. GCN Circular #17688) 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 2015-04-13 15:58:02 UT (~2.1 h after the burst).
We detected the previously reported optical afterglow (K.Ivanov et al. GCN Circular #17689) in the Ic band.

The measured magnitudes are listed below.

T0+  MID-UT  T-EXP[sec]    g'                Rc             Ic
----------------------------------------------------------------------
263 min   4/13 18:17:28  240     > 17.3  > 17.2  16.09 +/- 0.30
2.04 days   4/15 14:52:50  15960    > 21.7  > 21.5  > 20.2
----------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.