TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4954 SUBJECT: GRB 060403: MITSuME optical observation DATE: 06/04/05 06:08:19 GMT FROM: Nobuyuki Kawai at Tokyo Tech K. Yanagisawa (OAO/NAO) and N. Kawai (Tokyo Tech) report on behalf of the Mitsume Collaboration: "The field of GRB060403 (Boyd et al. GCN 4945, Mangano et al. GCN 4947) was observed with the 3-color MITSuME 50cm Telescope at Okayama, Japan starting at 16:59 UT until 16:22 UT (mid-epoch 16:10 UT, t_burst+3 hr) in g', Rc, and Ic bands simultaneously. With the total effective exposure of 18 min (60s x 18 frames), we did not detect a source brighter than g'=18.3, Rc=18.3, and Ic=17.9. (3 sigma) at the position of the XRT error circle. We placed the images at http://bragi.oao.nao.ac.jp/support/telescope/grb50/images/GRB060403.png"