TITLE: GCN CIRCULAR NUMBER: 19080 SUBJECT: GRB 160225A: MITSuME Akeno Optical Observation DATE: 16/02/25 17:53:11 GMT FROM: Taketoshi Yoshii at Tokyo Tech T. Yoshii, Y.Saito, T.Fujiwara, Y. Tachibana, Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 160225A (M. H. Siegel et al., GCN Circular #19075) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2016-01-04 14:24:14 UT (198 sec after the burst) and we detected the optical counterpart in Rc and Ic band. The measured magnitudes were listed as follows. We obtained following limits for the magnitudes. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------------------------------- 378 14:27:14 270 > 19.4 18.2 +/- 0.1 17.1 +/- 0.2 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.