GCN Circular 28571

N. Ito, R. Hosokawa, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa, N.
Nakamura, 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 201006A (J.D. Gropp et al.,GCN #28560,
S.Mereghetti et al., GCN #28561, R. Hamburg et al., GCN # 28564) 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 at 13:31:53 UT. Since some images were heavily
affected by bad weather and the moon, we stacked the images with good
conditions. We did not find any new point sources within the enhanced
Swift/XRT circle (M.R. Goad et al., GCN #28562) in all three bands.
We obtained the 5-sigma limits as follows.
T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
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12.2 16:27:01 4020.0 g'>19.5,Rc>19.4,Ic>18.9
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T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used 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., accepted for publication in PASJ;
arXiv2008.11486
https://github.com/MNiwano/Eclaire)