[vsnet-grb-info 20421] GRB 180316A: MITSuME Okayama optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22517
SUBJECT: GRB 180316A: MITSuME Okayama optical upper limits
DATE:    18/03/19 07:23:59 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata at u.phys.nagoya-u.ac.jp>

K. L. Murata, R. Itoh, T. Yoshii, 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 180316A (A. Melandri  et
al., GCN Circular #22500) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of  Okayama Astrophysical
Observatory, Japan.

The observation started on 16:19:04 UT. We did not find any new point
source within enhanced XRT circle (P.A. Evans et al., GCN Circular #22508)
in all three bands.
We obtained following limits for the magnitudes.


T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------
-------------------------------------------
12.22       19:44:32      1980     >17.3     >17.4     >17.4
------------------------------------------------------------
-------------------------------------------

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