TITLE: GCN CIRCULAR NUMBER: 7363 SUBJECT: GRB 080307: Optical observation with DMC/KANATA DATE: 08/03/07 12:33:44 GMT FROM: Makoto Uemura at Hiroshima U M. Doi, S. Sako, J. Hayano, Y. Ihara, N. Takanashi, H. Kuncarayakti (The Univresity of Tokyo), D. Kuroda (NAOJ), K. S. Kawabata, and M. Uemura (Hiroshima Univ.) report on behalf of the DMC team: We took optical CCD images of the field of GRB 080307 (GCNC 7362) with Dichroic Mirror Camera (DMC; http://www.ioa.s.u-tokyo.ac.jp/dmc/) attached to the 1.5-m KANATA telescope. DMC enables us to simultenaously obtain 15 band images in the optical range (typical delta lambda = 35 nm). We started observations at 11:31:18 (UT) 7 March 2008, 467 s after the burst. The exposure time was 60 s. No candidate of its optical afterglow brighther than r=17.13 mag (USNO B1.0 1251-0170228; RA=09:06:33.62, Dec=+35:08:44.1) was found in our all images. YYYYDDMM(UT) limit mag. center of wavelengths 20080307.4804 17.13 r 641nm (chanel 07 of DMC)