TITLE: GCN CIRCULAR NUMBER: 9202 SUBJECT: GRB 090423: UKIRT K-band observations DATE: 09/04/23 10:51:23 GMT FROM: Nial Tanvir at IofA U.Cambridge N. Tanvir (U. Leicester), A. Levan (U. Warwick), T. Kerr (JACH), T. Wold (JACH) We observed the field of GRB 090423 with WFCAM on UKIRT, beginning at 08:16 (UT), approximately 20 minutes post-burst. We detect a faint source in the K-band image just outside the revised XRT error circle, at coordinate: 09 55 33.29 +18 08 57.8 (J2000, estimated uncertainty 0.3 arcsec) The source has a magnitude K~17.5, but does not appear in SDSS images, and therefore is very red. The image is also extended in the E-W direction, and so might be (or include) a dusty host galaxy. However, we caution that the images are slightly trailed and so further work is required to determine whether this source is a point source or not.