TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4060 SUBJECT: GRB 050906, summary of radio observations DATE: 05/10/05 19:17:44 GMT FROM: Dale A. Frail at NRAO P. B. Cameron (Caltech) and D. A. Frail (NRAO) report on behalf of a larger collaboration: "Following our preliminary radio observations (GCN#3933), we have undertaken four further observations of the field of GRB050906 with the VLA at frequency of 8.46 GHz. In time order, they were centered on the possible X-ray counterpart position (GCN#3956), the previously reported radio source (GCN#3933), and two epochs of the refined BAT error circle (GCN#3935). The observations were taken on September 10.35, 11.50, 11.52 and October 3.41 (all dates UT). We find no radio sources within the XRT error circle with a limiting 2 sigma flux density of 61 uJy. The previously identified radio source, (GCN#3933), which now lies outside of the refined BAT error circle, has shown no significant variability and is likely a background extragalactic source. Within the refined BAT error circle (GCN#3935) there are no significantly variable radio sources. The typical rms noise of each observation is 40-50 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."