TITLE: GCN CIRCULAR NUMBER: 9249 SUBJECT: VLA radio observation of high-z GRB 090423 DATE: 09/04/25 10:41:23 GMT FROM: Poonam Chandra at U Virginia/NRAO "Poonam Chandra (RMC), Dale A. Frail (NRAO) and S. R. Kulkarni (Caltech) report on behalf of a larger collaboration: "We used the Very Large Array to observe the field of view toward the high redshift GRB 090423 (GCN 9198) at a frequency of 8.46 GHz on 2009 Apr. 25.00 UT. We do not detect any radio emission either within the Swift-XRT error circle (GCN 9205) or at the UKIRT K-band position (GCN 9202). The 3-sigma upper limit on the radio flux density of GRB afterglow is 135 uJy (map rms 45 uJy). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."