GCN Circular 9892
K. Nishimoto, T. Sako, and D. Suzuki (STE Lab, Nagoya Univ.) on behalf of the MOA Collaboration report: We searched for an optical afterglow of GRB090904B (GCN9881, V. D'Elia et al.) starting from 07:34:56.9 UT on 2009 Sep 4 (6 hours after the burst) with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand. In a single image of a 60 sec exposure with a wideband Red filter (center wavelength ~ 750nm and FWHM ~ 250nm), we did not find any object within the error circle of the Swift XRT source position (GCN 9887), except a USNO-B1.0 catalog star, 0647-0516939, which has I mag=15.10 and the separation of 1.8 arcsec from the center of the position. Quick estimation of the limiting magnitude is >20.5 calibrated by using USNO-B1.0 catalog.