TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3489 SUBJECT: GRB 050525: MITSuME Optical Observation in VRI DATE: 05/05/26 15:49:41 GMT FROM: Nobuyuki Kawai at Tokyo Tech K. Yanagisawa (OAO/NAOJ), H. Toda, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: "We observed the field of GRB 050525 (Band et al.; GCN 3466) with the 3-color MITSuME 50cm Telescope at Okayama, Japan starting at 12:03(UT) on May 25, 2005. We obtained a 5400 sec exposure (120 sec x 45 frames; midtime=13:02 UT) simultaneously in V, R, and I-bands. We confirmed the optical afterglow (Rykoff et al.; GCN 3465) in R and I bands at the position RA=18:32:32.6, DEC=+26:20:22 (J2000) with magnitudes R = 19.30 +/- 0.17 and I = 20.12 +/- 0.29. We did not detect the optical transient in the V-band image with an upper limit of V=19.2."