TITLE: GCN CIRCULAR NUMBER: 7166 SUBJECT: X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus DATE: 08/01/11 15:44:16 GMT FROM: Denis Denissenko at IKI, Moscow D. Denisenko (IKI, Moscow), S. Korotkiy (Ka-Dar obs.), T. Kryachko (Astrotel obs., KSU), B. Satovskiy (Astrotel obs., KSU), K. Sokolovsky (ASC LPI, SAI MSU) report: We took three 300-sec unfiltered images of NGC 2770 between 19:00 and 19:18 UT on 2008 Jan 10 with 300-mm f/7.7 robotic telescope equipped with STL-11000M CCD camera. The telescope is located at Kazan State University Astrotel observatory (Karachay-Cherkessia, Russia). The optical source reported by Deng & Zhu (GCN 7160) and Thoene et al. (GCN 7161) is clearly detected on individual images with SNR=18. Using the same comparison star as in D'Elia et al. (GCN 7162), we have measured unfiltered magnitude (with R zero-point) of the transient 18.1+/-0.1 (JD 2454476.2979). The finding chart is available at ftp://scan.sai.msu.ru/pub/XRT_NGC2770/OT-NGC2770-Astrotel.jpg The individual fits images can be downloaded from ftp://scan.sai.msu.ru/pub/XRT_NGC2770/ This message can be cited. [GCN OPS NOTE(21jan08): "Astrotel-Caucasus" was added to the end of the Subject-line.]