TITLE: GCN CIRCULAR NUMBER: 18805 SUBJECT: GRB 160101A: MITSuME Akeno optical upper limits DATE: 16/01/02 17:14:36 GMT FROM: Taketoshi Yoshii at Tokyo Tech T.Fujiwara, Y.Saito,T.Yoshii, Y.Tachibana, Y.Yano, Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 160101A (D.Itoh et al., GCN Circular #18793) 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 2016-01-01 18:33:56 UT (~17.8 h after the burst). We cound not detect any optical point source in the error circle of the previously reported afterglow detected by Swift-XRT (L.Izzo et al., GCN Circular #18795) in all three bands. Three sigma upper limits are listed below. T0+[hour] MID-UT T-EXP[sec] g' Rc Ic --------------------------------------------------------------------------------------- 18.9839 20:18:08 780 > 18.5 > 18.2 > 17.4 --------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration