TITLE: GCN CIRCULAR NUMBER: 18833 SUBJECT: GRB 160104A: Nishi-Harima MINT Observations DATE: 16/01/06 04:49:49 GMT FROM: Tomohito Ohshima at Nishi-Harima Obs GRB 160104A: Nishi-Harima MINT Observations K. Morihana. J. Takahashi, Y. Takagi, S. Honda, T. Ohshima, and Y. Itoh (Univ. of Hyogo), report on behalf of Nayuta team and OISTER collaboration: We observed the field of GRB 160104A (Melandri et al. GCN 18815) with Multiband Imager for Nayuta Telescope (MINT) attached to the Nayuta 2-m telescope at the Nishi-Harima Astronomical Observatory. The observations were started at 12:01 UT on 2016-01-4 (~35 minuets after the burst). We detected the optical afterglow in Rc band within the error circle of Swift/XRT. Photometric results of our observations are shown below. We used nearby NOMAD catalogue stars for the photometric calibration. # MID-UT Tmid-T0 T-EXP Rc_mag ---------------------------------------------------------------------- 12:37:32 0.0509 4200s 21.6+/-0.5 ---------------------------------------------------------------------- Tmid-T0: Elapsed time after the burst (day) T-EXP: Total Exposure time (seconds)