TITLE: GCN CIRCULAR NUMBER: 9141 SUBJECT: GRB 090417B: optical observations DATE: 09/04/18 01:25:33 GMT FROM: Igor Volkov at Asro.Inst.Slovak Acad.Sciences On 2009 April 17 I observed the field of GRB 090417B (Sbarufatti et al. GCN Circ. 9135) with the 0.5m reflector and ST-10XME CCD camera of Stara Lesna (Slovak Republic) observatory. I have got 11 frames in standard Rc system, starting at 22:10:05 UT, 23332s after the alert. In my coadded frame (total exposition 930s)it was not possible to detect a single source inside the refined XRT error box (Sbarufatti et al. GCN Circ. 9135) with S/N rate more than 5, which corresponds to limiting magnitude Rc >19.9. The time of the middle of the sequence was 22:18:00 UT. GSC2.3 catalog was used for flux calibration. Igor Volkov, visiting astronomer of Astronomical Institute of the Slovak Academy of Sciences, 059 60 Tatranska Lomnica, Slovak Republic; Sternberg Astronomical Institute, 119992 Moscow, Universitetskij pr.13; e-mail: volkov@ta3.sk, imv@sai.msu.ru