GRB 200122A: MITSuME Akeno optical upper limits

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 ------------------------------------------------------------------------------------------------ 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)