[vsnet-grb-info 19914] GRB 171010A: MITSuME Akeno Optical Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22001
SUBJECT: GRB 171010A: MITSuME Akeno Optical Observation
DATE:    17/10/12 02:53:40 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata at u.phys.nagoya-u.ac.jp>

S. Harita, R. Itoh, K. L. Muarata, Y. Tachibana, T. Yoshii, K. Morita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We have been observing the optical counterpart of GRB 171010A (N. Omodei et
al., GCN Circular #21985) 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 2017-10-11 13:29:52.24 UT.
We detected the previously reported optical afterglow (Thorstensen &
Halpern, GCN Circular #21987; Izzo & Malesani, GCN Circular #21988;
Guidorzi et al., GCN Circular #21991; Malesani et al., GCN Circular #22000)
in Ic and Rc bands.
The measured magnitudes were listed as follows.

T0+[hour]    MID-UT      T-EXP[sec]         g'              Rc
       Ic
-------------------------------------------------------------------------------------------------------
~18.29         15:23:32          4380           >18.8    18.04+/- 0.16
 17.331 +/- 0.12
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.