[vsnet-grb-info 14859] GRB 140423A: MITSuME Akeno Optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16173
SUBJECT: GRB 140423A: MITSuME Akeno Optical observation 
DATE:    14/04/25 14:28:40 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac at m.titech.ac.jp>

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

We observed the field of GRB 140423A (E. Sonbas et al., GCN Circular #16142) 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 2014-04-23 12:38:42 UT (4.1h after the burst).
We detected the previously reported optical afterglow of GRB140423A (D.Kuroda et al., GCN Circular #16160) in the Rc and Ic band.

The measured magnitudes were listed below.

T0+[sec]     MID-UT       T-EXP[sec]              g'                         Rc                      Ic
-------------------------------------------------------------------------------------------------------------------
19710       14:00:28         7740            20.49+/-0.23      19.83+/-0.15    19.72+/-0.22
31955       17:24:28         7560                    >21.3           20.35+/-0.19    19.89+/-0.23
-------------------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst 
T-EXP: Total Exposure time 
We used GSC2.3 catalog for flux calibration.