TITLE: GCN CIRCULAR NUMBER: 11513 SUBJECT: GRB110102A: MITSuME Okayama Optical Observation DATE: 11/01/03 10:09:15 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 110102A (Oates et al., GCN 11509) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2011-01-02 20:08:45 UT (~1.3 hours after the burst). We detected the afterglow candidate within the enhanced XRT error circle (Goad et al., GCNC 11510) in all the three bands. Photometric results are listed below. We used SDSS catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err ---------------------------------------------------------------------- 0.06851 20:31:04 2340.0 20.0 0.4 19.6 0.3 18.3 0.2 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]