TITLE: GCN CIRCULAR NUMBER: 6171 SUBJECT: GRB 070306: Optical and IR observations with KANATA DATE: 07/03/06 18:45:46 GMT FROM: Makoto Uemura at Hiroshima U M. Uemura, A. Arai, and T. Uehara (Hiroshima Univ.), report on behalf of the KANATA GRB team: We took optical and IR images of the field of GRB070306 (GCN 6169) at 16:57-17:18 UT 6 Mar. using TRISPEC attached to the KANATA 1.5-m telescope at Higashi-Hiroshima Observatory, Japan. The observation was performed with a bad seeing under strong wind. We obtained 10 sets of Rc, J, and Ks-band images with a 123, 120, and 96-s exposure time, respectively. The images were calibrated with neighbor stars in the USNO A2.0 and 2MASS catalog. We cannot significantly detect the optical and IR afterglows at the XRT position reported in GCN 6169. The limit magnitudes are below: UT Limit mag Exp. Time Mar. 6.71383 Rc > 20.3 123 * 10 Mar. 6.71378 J > 17.3 120 * 10 Mar. 6.71363 Ks > 15.1 96 * 10