TITLE: GCN CIRCULAR NUMBER: 6501 SUBJECT: GRB 070610: Optical observations from OSN DATE: 07/06/11 14:51:12 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo, A.J. Castro-Tirado, F. Aceituno (IAA-CSIC) on behalf of a larger collaboration report: "We have imaged the field of GRB 070610 (Pagani et al. GCNC 6489) with the 1.5m OSN telescope in Granada (Spain) using V, R and I filters. The observations were obtained starting at 02:44:55 UT (5.87 hours after the burst). Inside the XRT error box (Pagani et al. 6490) we detect the afterglow reported by Stefanescu et al. (GCNC 6492) with R~21.5 at the following coordinates (J2000) with an uncertainty of 0.5 arcsec: A.R.: 19:55:09.63 Dec.: +26:14:05.6 A finding chart can be found at: http://www.iaa.es/~deugarte/GRBs/070610/GRB070610.gif " This message may be quoted.