TITLE: GCN CIRCULAR NUMBER: 8619 SUBJECT: GRB081203A: MITSuME optical observation DATE: 08/12/05 11:04:48 GMT FROM: Michitoshi Yoshida at Okayama Astrophysical Obs Y. A. Mori, H. Nakajima, T. Shimokawabe, N. Kawai (Tokyo Tech), D. Kuroda, M. Yoshida, K. Yanagisawa, Y. Shimizu, H. Toda, and S. Nagayama (OAO, NAOJ) report on behalf of the MITSuME collaboration: We performed optical imaging observation of the field of GRB 081203A (Parsons, et al., GCN Circ. 8595) with the 3-color 50cm MITSuME Telescopes at Akeno Observatory and Okayama Astrophysical Observatory from UT 17:50 to UT 20:55, 3.9 hours after the trigger. In the co-added images of Rc, and g' bands, we detected the optical afterglow detected with UVOT (Parsons, et al., GCN Circ. 8595). Photometric calibration was done using the GSC2.3 catalogs. The results are following: Akeno: MID-MJD MID-UT EXP-T g' Rc ---------------------------------------------------------- 54803.753779 18:12:54 1620.0 18.50+/-0.24 18.11+/-0.25 ---------------------------------------------------------- Okayama: MID-MJD MID-UT EXP-T g' Rc ---------------------------------------------------------- 54803.790960 18:58:59 1500.0 18.87+/-0.26 18.36+/-0.19 54803.811830 19:29:03 1500.0 19.18+/-0.25 17.89+/-0.15 54803.833037 19:59:35 1560.0 19.11+/-0.23 18.49+/-0.24 54803.854522 20:30:31 1560.0 19.63+/-0.32 18.91+/-0.19 ----------------------------------------------------------