TITLE: GCN CIRCULAR NUMBER: 20285 SUBJECT: GRB 161217A: MITSuME Okayama upper limits DATE: 16/12/18 15:22:08 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 161217A (D'Elia et al., GCNC 20276) 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 2016-12-17 12:40:15 UT (~11.2 h after the burst). We did not find any new point source within the Enhanced XRT circle (Osborne et al., GCNC 20278) in all the three bands. Three sigma upper limits of the OT are listed below. We used SDSS-DR8 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 0.51298 13:46:16 5760.0 >19.1 >19.1 >18.4 0.76490 19:49:01 6180.0 >20.1 >19.9 >19.1 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]