TITLE:   GCN CIRCULAR
NUMBER:  28992
SUBJECT: GRB 201203A: MITSuME Okayama optical upper limits
DATE:    20/12/04 08:01:15 GMT
FROM:    Masafumi Niwano at Tokyo Institute of Tech  <niwano@hp.phys.titech.ac.jp>

M. Niwano, R. Hosokawa, K. L. Murata, R. Adachi, F. Ogawa, N. Nakamura,
N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai (TokyoTech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 201203A (S. Dichiara et al.,GCN Circular 
#28985) with the optical three color (g', Rc, and Ic) CCD cameras 
attached to the MITSuME 50 cm telescope of Okayama Astrophysical 
Observatory, Okayama, Japan.
The observation started at 12:02:06 UT. We did not find any new point 
sources within the Swift-XRT circle ( V. D'Elia et al., GCN Circular 
#28990) in all three bands.
We obtained the 5-sigma limits as follows.
T0+[hour]  MID-UT  T-EXP[sec]  5-sigma limits
------------------------------------------------------------------------------------------------ 

6.9  13:45:28.19  9000  g'>17.9, Rc>18.6, Ic>17.7
------------------------------------------------------------------------------------------------ 

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used the PS1 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., 10.1093/pasj/psaa091, arXiv:2008.11486; 
https://github.com/MNiwano/Eclaire).