TITLE: GCN CIRCULAR NUMBER: 9733 SUBJECT: GRB 090727: optical observations DATE: 09/07/29 12:31:34 GMT FROM: Vladimir Sokolov at SAO RAS A. Moskvitin, A. Valeev, T. Fatkhullin, O. Sholukhova & S. Fabrika (SAO-RAS Niznijh Arkhyz, Russia), on behalf of a larger colaboration, report: We observed the GRB090727 optical afterglow (Smith et al. GCN Circ. 9719, GCN Circ. 9722; J. Gorosabel et al. GCN Circ 9728 ) with the SAO RAS 6-m telescope in Caucasus. The observations were carried out in the R band with a total exposure of 158 sec. The weather was cloudy with a sufficient atmospheric extinction. We estimated the brightness of the object as R = 21.53 +/- 0.17 at the middle epoch of 23:21:12 27 July 2009 UT (2334 sec after the trigger). Calibration was done aganist 10 USNO B1.0 stars. This message may be cited.