Kenshi Yanagisawa, Tsuyoshi Sakamoto (OAO/NAOJ), and N. Kawai (Tokyo
Tech) report on behalf of the MITSUME Collaboration:
"The field of GRB051227 (Barbier et al., GCN 4397) was observed with
the 3-color Mitsume 50cm Telescope at Okayama, Japan from 19:13 UT to
19:21 UT (1.1 to 1.4 hours after the burst), until the observation was
terminated by the cloudy weather. Coadding the 14 frames of 60 sec
exposure, we did not detect a source at the position of the afterglow
candidate noted by Malesani et al. (GCN 4404, 4407, 4412), Bloom et
al. (GCN 4408), Berger et al. (GCN 4410) and Roming et al. (GCN 4411).
The 10-sigma upper limits are g'=18.5, Rc=17.7, and Ic=17.1, which
were calibrated using the pre-burst SDSS observations (stars in the
file GRB051227_sdss.objects_magnitudes.dat, Cool et al., GCN 4399),
where the Rc and Ic magnitudes were converted from the g', r', and i'
magnitudes using the formula by Smith et al. (2002)."