GCN Circular 9248
M. Im, W. Park, Y. Jeon, I. Lee (CEOU/Seoul National Univ), Y.-B. Jeon (KASI) and Y. Urata (NCU) on behalf of EAFON team. We took BVRI-band images of GRB090424 (GCN 9223) using the 1.0m telescope at Mt. Lemmon (Arizona, US) operated by the Korea Astronomy Space Science Institute. The whole sequence of the observation started at 2009 April 25, 04:30:19 UT, among which R-band observation started at 04:58:32.22. From a stacked image of 6 frames (3 min exp. each), we cleary detect the afterglow at R=19.9 +- 0.14 mag, calibrated against USNO-B1 stars in the vicinity. The mid-point of the obseravation is April 25, 05:10:57 UT (14.97 hrs after the burst). Analysis of the BVI data is ongoing. We thank the LOAO operator, J. Yoon for his assistance for this observation.