TITLE: GCN CIRCULAR NUMBER: 7676 SUBJECT: GRB 080503: MITSuME Ishigakijima optical upper limits DATE: 08/05/04 03:04:00 GMT FROM: Nobuyuki Kawai at Tokyo Tech D. Kuroda, K. Yanagisawa (NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the error box of GRB 080503 (Mao et al. GCN 7665) with the 3-color 105cm Telescope at Ishigakijima Astronomical Observatory starting at 2008-05-03 13:49:55 UT, 1.4 hours after the trigger. In the co-added images of Ic, Rc, and g' bands, we did not detect any afterglow candidate. The 3-sigma limiting magnitudes based on USNO-B1.0 (I-band) and NOMAD (R-band,g'-band) stars are following. Filter start (UT) end (UT) Exposure LimitMag --------------------------------------------------- g' 13:49:55 13:59:19 9 x 60 s 20.5 Rc 13:49:55 13:59:19 9 x 60 s 20.2 Ic 13:49:55 13:59:19 9 x 60 s 20.1 ----------------------------------------------------