TITLE: GCN CIRCULAR NUMBER: 9274 SUBJECT: GRB 090423: CARMA mm observations DATE: 09/04/28 01:57:49 GMT FROM: Poonam Chandra at U Virginia/NRAO D. C.-J. Bock (CARMA), P. Chandra (RMC), D. A. Frail (NRAO), and S. R. Kulkarni (Caltech) report on behalf of a larger collaboration: "We observed the field of view of GRB 090423 (GCN 9198) with the Combined Array for Research in Millimeter-Wave Astronomy (CARMA) at a frequency of 92.5 GHz at the mean observation time of 2009 April 25, 0440 UT. We do not detect mm 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 flux density of GRB afterglow is 0.7 mJy. We acknowledge excellent support from the staff and observers at CARMA."