GCN Circular 7686
K. S. Kawabata, M. Sasada, M. Uemura, T. Yamashita and T. Ohsugi (Hiroshima Univ.) and R. G. Lundock (Tohoku Univ.) report on behalf of KANATA/TRISPEC observation team: We performed a series of simultaneous optical(Rc) and NIR (J, Ks) imaging observations for the optical counterpart associated with GRB 080506 (Baumgartner et al, GCN 7685) using TRISPEC attached to the 1.5-m KANATA telescope. Our quick-look analysis showed that Rc magnitude of the counterpart was 17.5 at 220 sec after the BAT trigger. It then faded and reached 19.5 at ~5050 sec. We used USNO A2.0 1275-16800533 (R=15.1) and 1275-16801542 (R=15.1) stars for comparison. Further analysis is ongoing.