GCN Circular 7026
Subject
GRB 071020: MITSuME Akeno optical observations
Event
Date
2007-10-31T11:38:14Z (18 years ago)
From
Nobuyuki Kawai at Tokyo Tech <nkawai@hp.phys.titech.ac.jp>
T. Ishimura, Y. Yatsu, T. Shimokawabe, N. Kawai (Tokyo Tech) and
M. Yoshida (NAOJ) report on behalf of the MITSuME collaboration:
We observed the field of GRB 071020 (Holland et al. , GCN6949) with
the 3-color 50cm MITSuME Telescope at Akeno, Japan from UT 16:21 to
UT 19:53 on Oct. 20, 9.3 hours after the trigger.
In the co-added images of Ic and Rc bands, we detected the optical
afterglow reported by Schaefer et al. (GCN 6948). Photometric
calibration was done using the USNO-B1.0 (Ic-band) and NOMAD (g'- and
Rc-bands) catalogs. The results are following:
Filter start end Exposure Mag
------------------------------------------------------
g' 16:21:13 19:53:55 149 x 60s >21.1 (3 sigma upper limit)
Rc 16:21:13 19:53:55 149 x 60s 21.2 +/- 0.3
Ic 16:21:13 19:53:55 149 x 60s 19.8 +/- 0.3
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