TITLE: GCN CIRCULAR NUMBER: 6721 SUBJECT: GRB070808: Optical observations with KANATA DATE: 07/08/08 19:42:51 GMT FROM: Makoto Uemura at Hiroshima U M. Uemura, A. Arai, M. Sasada, M. Isogai, T. Uehara (Hiroshima Univ.), and D. Nogami (Kyoto Univ.) report on behalf of the KANATA GRB team: We started optical imaging of the field of GRB070808 (GCN 6718) at 18:29:38 UT 8 Aug. using TRISPEC attached to the KANATA 1.5-m telescope at Higashi-Hiroshima Observatory, Japan. Exposure times for Rc-band images are 30 sec. No new object was significantly detected. In our first image, a limit magnitude was estimated from neighbour USNO A2.0 stars as below: 18:29:53 UT 8 Aug. 20.5 Rc Follow-up observations are ongoing.