[vsnet-grb-info 25862] GRB 200613A: MITSuME Akeno optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27962
SUBJECT: GRB 200613A: MITSuME Akeno optical upper limits
DATE:    20/06/16 01:48:34 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata at u.phys.nagoya-u.ac.jp>

K. L. Murata, N. Ito, R. Hosokawa, 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 200613A (Fermi GBM team, GCN 27926; Bissaldi
et al., GCN 27930; Ohno et al., GCN 27931) 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 2020-06-15 11:33. We did not detect the optical
afterglow (Kann et al., GCN 27935; Kennea et al., GCN 27936; Pozanenko et
al., GCN 27937; Izzo et al., GCN 27939; Zhu et al., GCN 27943; Marshall et
al., GCN 27944; Liu et al., GCN 27949; Belkin et al., GCN 27958) in the
stacked image. We obtained the 5-sigma limits as follows.

T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
54 2020-06-15T12:29:27 2040 g'>19.3, Rc>19.5, Ic>18.6
------------------------------------------------------------------------------------------------
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., submitted;
https://github.com/MNiwano/Eclair)