GCN Circular 6430
Subject
GRB 070520A: MITSuME Akeno optical upper limits
Date
2007-05-21T04:19:51Z (18 years ago)
From
Nobuyuki Kawai at Tokyo Tech <nkawai@hp.phys.titech.ac.jp>
T. Ishimura, T. Shimokawabe, N. Vasquez, Y. Yatsu, Y. Kudou and
N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB070520A (Romano et al., GCN 6423)
with the 3-color 50cm MITSuME Telescope at Akeno, Japan starting
at 13:15:15 UT, 10 min after the trigger, under a clear, but windy
condition.
In the co-added images of Ic, Rc, and g' bands, we did not detect
any new source in the XRT error circle. The 3-sigma limiting
magnitudes based on USNO-B1.0 (I-band) and NOMAD (R-band,g'-band)
stars are following.
Filter start time end time Exp(s) Mag (3-sigma UL)
-----------------------------------------------------------
Ic 13:15:15 15:06:06 60s * 91 20.3
Rc 13:15:15 15:06:06 60s * 91 21.2
g' 13:15:15 15:06:06 60s * 91 21.1
-----------------------------------------------------------