TITLE: GCN CIRCULAR NUMBER: 31137 SUBJECT: GRB 211129A: MITSuME Akeno optical upper limits DATE: 21/11/29 10:36:23 GMT FROM: Ryohei Hosokawa at Tokyo Institute of Technology R. Yamaguchi, R. Hosokawa, Y. Imai, K. L. Murata, M. Niwano, Y. Takamatsu, N. Ito, R. Noto, S. Sato, M. Takaku, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration: We observed the field of GRB 211129A(J.D. Gropp et al. GCN Circular #31136) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 10 sec exposures started at 2021-11-29 09:52:06 UT (60 seconds after Swift trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the XRT error region (J.D. Gropp et al. GCN Circular #31136). We obtained the 5-sigma limits of the stacked images as follows. T0+[sec] MID-UT T-EXP[sec] 5-sigma limits ------------------------------------------------------------------------------------------------ 159 2021-11-29 09:53:45 70 g'>17.0, Rc>17.3, Ic>16.4 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).