TITLE: GCN CIRCULAR NUMBER: 6453 SUBJECT: GRB 070521, optical observation DATE: 07/05/22 10:20:04 GMT FROM: Shouta Maeno at U.of Miyazaki S.Maeno, R.Hara, H.Tanaka, E.Sonoda, M.Yamauchi (University of Miyazaki) We have observed the field of GRB 070521 (GCN 6431) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started from 11:47:35 UT on May 21(4.9 h after the trigger). After co-adding a set of 32 images (11:47:35 - 12:46:04 UT) of 30 sec exposures, we have compared with the USNO A2.0 catalog. Preliminary analysis shows there is no new source brighter than 17.8mag.