[vsnet-grb-info 20659] GRB 180602A: MITSuME Akeno optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22757
SUBJECT: GRB 180602A: MITSuME Akeno optical upper limits
DATE:    18/06/03 09:29:22 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata at u.phys.nagoya-u.ac.jp>

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

We searched for the field of GRB 180602A (Cenko et al., GCN Circular
#22752) 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 2018-06-02 11:12:09 UT (~3 hours after the
burst). We did not find any new point source within the enhanced XRT error
circle (Osborne et al., GCN Circular #22753) in all the three bands.


T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------
-------------------------------------------
~3.1        ~12:24       1200     >18.9     >18.3     >18.0
------------------------------------------------------------
-------------------------------------------

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