TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2750 SUBJECT: GRB 040924: detection of possible host galaxy by Subaru DATE: 04/09/26 03:45:04 GMT FROM: Nobuyuki Kawai at Tokyo Tech H. Terada, M. Akiyama (Subaru Telescope, NAOJ) and N. Kawai (Tokyo Tech) report: "We have made the second epoch observation of the afterglow candidate (GCN 2734) of GRB 040924 (=H3564, GCN 2735) in the K'-band with IRCS on the 8.2m Subaru Telescope at 15:07-15:41 UT on September 25 (27.5 hours after the burst) for an integration time of 1200 seconds with an average seeing of 0.52 arcsec. At the position of the afterglow, we detected an extended source with magnitude K'=20.4 +/- 0.2. It is probably the afterglow of GRB 040924 with a significant contribution from its host galaxy. Comparison with the earlier flux (K'=17.5 at t=2.4 hr, Terada and Akiyama, GCN 2742) imply that the NIR afterglow decay index was steeper than -1. The image is available at http://www.hp.phys.titech.ac.jp/nkawai/grb/040924/."