TITLE: GCN CIRCULAR NUMBER: 13343 SUBJECT: GRB 120521C: EVLA 22 GHz Detection DATE: 12/05/25 15:16:06 GMT FROM: Ashley Zauderer at CfA A. Zauderer and E. Berger (Harvard) report on behalf of a larger collaboration: "We re-observed the position of GRB 120521C (GCN 13318) on 2012 May 23.12 UT (1.15 d after the burst) with the EVLA at 21.8 GHz. Within the enhanced Swift-XRT error circle (GCN 13324) we detect a brightening radio source with a flux density that is about a factor of two above our early 3-sigma limit of 50 uJy (GCN 13336). We conclude that this is the radio afterglow of GRB 120521C. Follow-up observations at multiple frequencies are in progress."