TITLE: GCN CIRCULAR NUMBER: 19081 SUBJECT: GRB 160225A: MITSuME Okayama Optical Observation DATE: 16/02/25 23:50:50 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 MITSuME and OISTER collaboration: We observed the field of GRB 160225A (Siegel et al., GCNC 19075) 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 2016-02-25 14:26:51 UT (~5.9 min after the burst). We detected the previously reported afterglow (Yoshii et al., GCNC 19080) in Rc and Ic bands. Photometric results and three sigma upper limit of the OT are listed below. We used SDSS-DR7 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic Ic_err ------------------------------------------------------------------ 0.00777 14:32:08 540.0 >19.4 18.6 0.2 17.8 0.2 ------------------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]