TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1163 SUBJECT: GRB 011121: NIR observations, host galaxy? DATE: 01/11/29 01:12:02 GMT FROM: Paul Price at RSAA, ANU at CIT S. Ryder (AAO), K. Gunn and N. Seymour (University of Southampton) with P.A. Price, B.P. Schmidt and T.S. Axelrod (RSAA, ANU) report: We have observed the field of the afterglow of GRB 011121 (GCN #1150) with the newly-commissioned Infra-Red Imager and Spectrograph (IRIS2) on the Anglo-Australian Telescope at 2001 Nov 28.7 UT. Preliminary reduction of 40 individual 60 sec images in Ks with 1.8 arcsec seeing reveal a faint source at the position of the afterglow (GCN #1155), on the outskirts of a galaxy centered approximately 1.5" E and 0.7" S (ie 9 kpc at z=0.36). At the resolution and depth of our observations, we cannot distinguish between this source being distinct from the galaxy or corresponding to an extension of the galaxy. We estimate our limiting magnitude as K = 19.1 mag. This message may be cited.