GCN Circular 26864

R. Adachi, K. L. Murata, M. Niwano, F. Ogawa, R. Hosokawa, N.
Nakamura, S. Toma, M. Oeda, K. Shiraishi, K. Iida, Y. Yatsu, and N.
Kawai(TokyoTech) report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 200122A (E. Sonbas et
al.,GCN Circular #26844) 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 14:39:41 UT. Then the observation stopped
due to the bad weather and started again at 16:20:20 UT. We did not
find any new point sources within the Swift-XRT error circle (J.P.
Osborne et al., GCN Circular #26846) in all three bands.

We obtained the 5-sigma limits as follows.

T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
14.66 17:41:47 7140 g'>18.6,Rc>18.8,Ic>18.1
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T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used Pan-STARRS DR1 catalog for flux calibration.
The magnitudes are expressed in the AB system.
The images were processed in real-time through the MITSuME GPU
reduction pipeline (Niwano et al. ,in prep;
https://github.com/MNiwano/Eclair)