TITLE: GCN CIRCULAR NUMBER: 7886 SUBJECT: GRB080613B: MITSuME upper limits DATE: 08/06/17 23:33:43 GMT FROM: Michitoshi Yoshida at Okayama Astrophysical Obs M. Yoshida, K. Yanagisawa, Kuroda, D., Y. Shimizu, S. Nagayama, Toda, H. (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We performed optical imaging observation (g', Rc, and Ic) of the field of GRB 080613B (Markwardt et al. GCN 7873) with 50cm MITSuME telescope at Okayama Astrophysical Observatory from 11:19:09 UT (6m 31s after the trigger) to UT 12:43:30 on June 13 2008. We could not identify any new source in the XRT error circle (Mao et al. GCN7875). Three sigma limiting magnitudes of our observation are listed below. Observation date: 2008-06-13 UT Start-UT mid-UT exp-T g' Rc Ic ---------------------------------------------------- 11:19:09 11:31:16 10min >18.4 >18.3 >18.0 11:31:26 12:07:28 60min >18.7 >18.4 >18.1 ----------------------------------------------------