TITLE: GCN CIRCULAR NUMBER: 6418 SUBJECT: GRB070518: OSN observation DATE: 07/05/19 01:04:27 GMT FROM: Martin Jelinek at Inst.Astrophys.Andalucia,Granada Martin Jelinek, Alberto J. Castro-Tirado, Victor Casanova, Javier Gorosabel, Antonio de Ugarte Postigo, Stanislav Vitek, Ronan Cunniffe and Petr Kubanek (IAA CSIC Granada, Spain) report We observed the optical afterglow of GRB070518 (Guidorzi et al, GCN6415) with a 1.5m telescope at Observatorio Sierra Nevada using R and I-band filters. The afterglow is found to have R~22.2, relatively to the nearby USNO-A2.0 (R_usno=18.7) on a 60-minute combined image with exposure mean time 23:04UT (i.e. 8.6h after the GRB). This message may be cited