TITLE: GCN CIRCULAR NUMBER: 9000 SUBJECT: GRB 090313: WSRT Radio Observations DATE: 09/03/15 16:16:34 GMT FROM: Alexander van der Horst at NASA/MSFC A.J. van der Horst (NASA/MSFC/ORAU) and A.P. Kamble (University of Amsterdam) report on behalf of a larger collaboration: "We observed the position of the GRB 090313 afterglow at 4.9 GHz with the Westerbork Synthesis Radio Telescope at March 14 21.06 UT to March 15 7.27 UT, i.e. 1.50 - 1.92 days after the burst (GCN 8980). We do not detect a radio source at the position of the optical counterpart (GCN 8979). The three-sigma rms noise in the map around that position is 114 microJy per beam. The formal flux measurement for a point source at the position of the optical counterpart is 26 +/- 38 microJy. We would like to thank the WSRT staff for scheduling and obtaining these observations."