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GCN Circular 22754

GRB 180602A: MITSuME Okayama optical upper limits
2018-06-02T12:30:27Z (6 years ago)
Yutaro Tachibana at Tokyo Tech <>
Y. Tachibana, R. Itoh, K. L. Murata, S. Harita, K. Morita,
T. Ozawa, H. Mamita, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration: 

We observed the field of GRB 180602A (Cenko et al., GCN Circular #22752)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2018-06-02 11:14:03.47 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.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
~3.07      ~11:18:47   420   >17.8   >17.7   >17.1

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