TITLE: GCN CIRCULAR NUMBER: 19771 SUBJECT: GRB 160804A: SAO RAS optical observations DATE: 16/08/05 01:07:20 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin, T. A. Fatkhullin (SAO RAS, Russia) and I. Soloviev (Saint-Petersburg Univ.), report on behalf of the larger team. We observed the field of the GRB 160804A (Marshall et al., GCN 19761) with the BTA, 6-meter telescope of SAO RAS, equipped with the Scorpio-I at 2016.08.04 17:52 UT (16.3 hours after the detection). A couple of Rc-band images (30 and 180 sec.) were obtained. The GRB OT (Breeveld & Marshall, GCN 19764; Tyurina et al., GCN 19768) is clearly detected in the stacked frame. The brightness of the object is R = 20.5 +/- 0.1 (calibration was done by the nearby SDSS stars, and Lupton 2005 transformation equations). The finding chart can be found at ftp://ftp.sao.ru/pub/grb/GRB160804A/GRB180804A_BTA.jpg