TITLE: GCN CIRCULAR NUMBER: 24016 SUBJECT: GRB 190326A: MITSuME Okayama optical upper limits DATE: 19/03/27 06:52:18 GMT FROM: Masafumi Niwano at Tokyo Institute of Tech M. Niwano,  K. L. Murata, R. Itoh, Y. Tachibana, K. Morita, K. Iida, K. Shiraishi, R. Adachi, M. Oeda,  Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration We searched for the optical counterpart of GRB 190326A (M. H. Siegel et al., GCN #24009) with optical three color (g', Rc, and Ic) cameras attached to the MITSuME 50 cm reflector in the Okayama Astrophysical Observatory, Japan. The observation started at 19:01:19 UT which corresponds to 41151 sec since the trigger. We did not find any new point source within the Swift BAT error circle (M. H. Siegel et al., GCN #24009) in all three bands. The obtained 5 sigma upper limits of the optical counterpart are summarize below: T0+[sec]    MID-UT      T-EXP[sec]    g'       Rc        Ic ------------------------------------------------------------------------------------------------------- 41151  19:33:27  600   >16.8     >16.8     >16.2 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used UCAC-4 catalog for flux calibration.