[vsnet-grb-info 20527] GRB 180410A: MITSuME Akeno optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22623
SUBJECT: GRB 180410A: MITSuME Akeno optical upper limits
DATE:    18/04/10 12:31:10 GMT
FROM:    Ryosuke Itoh at Tokyo Institute of Tech.  <itoh at hp.phys.titech.ac.jp>

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

We searched for the optical counterpart of GRB 180410A (J. D. Gropp et
al., GCN Circular #22620)
with the optical three color (g', Rc, and Ic) CCD cameras attached to
the MITSuME 50cm telescope
of Akeno Observatory, Yamanashi, Japan.
The observation started on 2018-04-10 10:02:24 UT.
We did not find any point source at the position of the XRT error
circle (P. A. Evans et al., GCN Circular #22622)
in all three bands. We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
~2.0           10:27:25       2,700         >18.8   >18.7   >18.0
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used UCAC-4 catalog for flux calibration.