TITLE: GCN CIRCULAR NUMBER: 9201 SUBJECT: GRB 090423: P60 Observations DATE: 09/04/23 09:46:20 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration: We have imaged the field of GRB090423 (GCN 9198, Krimm et al.) with the automated Palomar 60-inch telescope beginning at 2009 23 April 7:58 UT (~ 3 minutes after the burst) in the Sloan r', i', and z' filters. In coadded images we find no sources inside the XRT error circle to the following limiting magnitudes (calculated with respect to several SDSS stars in the field): Mean UT t_b (min) Filter Magnitude --------------------------------------------------------------------- 23 Apr 08:11 16 r' > 21.5 23 Apr 08:15 20 i' > 21.5 23 Apr 08:17 22 z' > 20.5 The lack of an optical afterglow, together with the fact that the X-ray column density is consistent with the Galactic value (Krimm et al., GCN 9198), make GRB090423 an interesting candidate high-redshift event. We encourage observations at longer wavelengths to search for a NIR counterpart.