TITLE: GCN CIRCULAR NUMBER: 9267 SUBJECT: GRB 090426: Near infrared observation with ISLE at OAO DATE: 09/04/26 23:50:04 GMT FROM: Michitoshi Yoshida at Okayama Astrophysical Obs M. Yoshida, D. Kuroda, K. Yanagisawa, Y. Shimizu, S. Nagayama, H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We detected the optical afterglow of GRB 090426 (Cummings et al. GCN 9254; Xin et al. GCN 9255; Oates et al. GCN 9265; Yoshida et al. GCN 9266) in near-infrared bands with the near-infrared camera ISLE attached to the 188cm telescope of Okayama Astrophysical Observatory. Photometric results are listed below. We used 2MASS stars in the FOV of ISLE for flux calibration. Band #PDAY MID-UT T-EXP mag error ---------------------------------------------- J 0.03534 13:39:41 720.0 18.6 0.2 H 0.03960 13:45:49 720.0 18.0 0.2 Ks 0.04336 13:51:13 720.0 17.6 0.2 ----------------------------------------------