GCN Circular 27236

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

We searched for the optical counterpart of GRB 200227A (Fermi GBM Team
et al.,GCN Circular #27233, S. Laha et al., GCN Circular #27234) 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 09:05:08 UT. We did not find any new point
sources within the Swift/XRT circle (S. Laha et al., GCN Circular
#27234) in all three bands.
We obtained the 5-sigma limits as follows.

T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
2.2   09:41:13  900  g���>18.4,Rc>18.2,Ic>17.5
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used UCAC4 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)