TITLE: GCN CIRCULAR NUMBER: 22505 SUBJECT: GRB 180314A: MITSuME Okayama optical upper limits DATE: 18/03/16 11:29:04 GMT FROM: Katsuhiro L. Murata at Nagoya U K. Shiraishi, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, K. Morita, T. Ozawa, H. Mamiya, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 180314A (P. D'Avanzo et al., GCN Circular #22478) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Okayama Astrophysical Observatory, Japan. The observation started on 10:32:06 UT. We did not find any new point source within enhanced XRT circle (J.P. Osborne et al., GCN Circular #22480) in all three bands. We obtained following limits for the magnitudes. T0+[hour] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------ ------------------------------------------- 9.99 12:03:20 7240 >19.3 >18.8 >18.6 ------------------------------------------------------------ ------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.