TITLE: GCN CIRCULAR NUMBER: 9771 SUBJECT: GRB 090812 VLT redshift DATE: 09/08/12 09:02:26 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo (INAF-OAB), J. Gorosabel (IAA-CSIC), J.P.U. Fynbo (DARK/NBI), K. Wiersema and N. Tanvir (Leicester) report on behalf of a larger collaboration We have observed the afterglow of GRB 090812 (Stamatikos et al. GCNC 9768) using FORS2 at the VLT (Paranal observatory) starting at 06:54 UT (52min after the burst). In the spectrum we detect strong absorption lines, including Ly-alpha, SiII, SiII*, CII, SiIV, CIV, SiII, AlII, AlIII, FeII, ZnII, MnII and TiII at a common redshift of 2.452 which we identify as the redshift of the GRB. We also detect absorption lines from an unidentified intervening system. Further analysis is ongoing. We acknowledge the excellent support from Paranal staff, in particular Jonathan Smoker, Cedric Ledoux and Karla Aubel.