TITLE: GCN CIRCULAR NUMBER: 20218 SUBJECT: GRB 161129A: MITSuME Okayama Optical Observation DATE: 16/11/30 00:35:47 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 161129A (Kocevski et al., GCNC 20210) 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 2016-11-29 08:54:33 UT (~1.7 h after the burst). We detected the previously reported source (Mazaeva et al., GCNC 20215; Klose and Stecklum, GCNC 20216) in Rc and Ic bands. Photometric results and three sigma upper limit of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic Ic_err ------------------------------------------------------------------ 0.11332 09:54:50 6120.0 >20.2 19.2 0.2 18.6 0.2 ------------------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]