GCN Circular 32138
Subject
GRB 220527A: MITSuME Akeno optical observation
Event
Date
2022-05-28T02:37:56Z (4 years ago)
From
Yuri Imai at Tokyo Inst of Tech <imai@hp.phys.titech.ac.jp>
Y. Imai, S. Sato, R. Hosokawa, K. L. Murata, M. Sasada, M. Niwano, N.
Ito, Y. Takamatsu, M. Tateda, T. Hattori, Y. Yatsu, and N. Kawai
(Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 220527A (A. Ursi et al. GCN Circular
#32129, The Fermi GBM team et al. GCN Circular #32130, Bissaldi et
al. GCN Circular #32131, Evans et al. GCN Circular #32132, Mangan et
al. GCN Circular #32133, Sbarufatti et al. GCN Circular #32135,
Tohuvavohu et al. GCN Circular #32136,) with the optical three color
(g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope
Akeno.
The observation with a series of 60 sec exposures started at
2022-05-27 16:05:50 UT (6.8 hours after the AGILE detection). We
stacked the images with good conditions. Here we report magnitudes by
the forced-photometry at the Swift/XRT position (Sbarufatti et al. GCN
Circular #32135).
T0+[hour] |MID-UT | T-EXP[sec] | magnitudes of forced-photometry
------------------------------------------------------------------------------------------------
7.5 | 2022-05-27 16:46:53| 3780 | g'=18.9 +/- 0.2, Rc=18.5 +/- 0.1,
Ic=18.3 +/- 0.1
8.7 | 2022-05-27 17:58:38| 3420 | g'=18.9 +/- 0.2, Rc=18.6 +/- 0.1,
Ic=18.7 +/- 0.2
------------------------------------------------------------------------------------------------
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. 2021, PASJ, Vol.73,
Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).