TITLE: GCN CIRCULAR NUMBER: 6386 SUBJECT: GRB 070508: Optical afterglow detection DATE: 07/05/08 05:22:41 GMT FROM: Edo Berger at Carnegie Obs E. Berger (Carnegie) and A. Burgasser (MIT) report: "We observed the position of GRB 070508 (GCN 6383) with MAGIC on the Magellan/Clay 6.5 m telescope starting 28 min after the burst. In a 180 sec I-band image we detect a bright object not visible in DSS within the XRT error circle at: RA = 20:51:12.07 DEC = -78:23:07.0 with an uncertainty of about 0.5". This is about 2.5" away from the UVOT position."