GCN Circular 18817

Y.Saito, T.Fujiwara, T. Yoshii, Y. Tano, Y. Tachibana,
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 160104A (A. Melandri et al., GCN 
Circular #18815) 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 2016-01-04 11:24:56 UT (46 sec after the burst) and 
we detected the optical counterpart in Rc and Ic band.
The measured magnitudes were listed as follows.

We obtained following limits for the magnitudes.

T0+[sec]    MID-UT      T-EXP[sec]         g'              Rc                      Ic
-------------------------------------------------------------------------------------------------------
61            11:25:11             30            > 18.5        17.9 +/- 0.3        16.5 +/- 0.2 
-------------------------------------------------------------------------------------------------------

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