TITLE: GCN CIRCULAR NUMBER: 22129 SUBJECT: GRB 171115A: MITSuME Okayama optical upper limits DATE: 17/11/16 12:36:01 GMT FROM: Katsuhiro L. Murata at Nagoya U K. Morita, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, T. Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 171115A (B. Sbarufatti et al., GCN Circular #22124) 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 2017-11-16 08:59:56 UT. We did not find any new point source within enhanced XRT circle (A.P. Beardmoreet al., GCN Circular #22125) in all three bands. We obtained following limits for the magnitudes. T0+[hour] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------------------------------- ~14.15 09:52:13.20 5100 >18.1 >17.5 >17.8 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.