TITLE: GCN CIRCULAR NUMBER: 6426 SUBJECT: GRB 070518: TNG observations DATE: 07/05/20 21:23:06 GMT FROM: Stefano Covino at Brera Astronomical Observatory S. Covino, G. Tagliaferri, G. Chincarini (INAF/OABr), L.A. Antonelli, G.L. Israel (INAF/Rome), G. Andreuzzi, A. Garcia de Gurtubai Escudero (INAF/TNG) on behalf of the CIBO collaboration, report: We observed the field of GRB070518 (GCN 6415, Guidorzi et al.) with the Italian Telescopio Nazionale Galileo (TNG) equipped with Dolores in the R band at about 10 and 35 hours from the burst. We clearly detected the optical afterglow (GCN 6415, Guidorzi et al.; GCN 6418, Jelinek et al.; GCN 6419, Cucchiara et al.). At about 35 hours from the burst the afterglow magnitude was R ~ 23.3. The decay index between the two epochs was about 0.5, significantly shallower than what reported at earlier times by Cucchiara et al. (GCN 6419). At about 2.5 arcsec NE of the afterglow we also detect a fainter source with no evidence of extended emission. Further observations are in progress. This message may be cited.