TITLE: GCN CIRCULAR NUMBER: 21764 SUBJECT: GRB 170830A: iTelescope optical observations DATE: 17/08/30 09:48:50 GMT FROM: Denis Denisenko at SAI MSU D. Denisenko (Sternberg Astronomical Institute, Moscow State University) reports: MAXI/GSC error box of GRB 170830A (T. Yoneyama et al., GCN 21761) was observed remotely by iTelescope.Net T32 instrument (0.43-m f/6.8 reflector + FLI Proline 16803 CCD) in Siding Spring, Australia, at 08:55-08:58 UT on 2017 Aug. 30 (5.7 hours after the trigger time). The telescope was centered at R.A. = 17 48 20, Decl. = -01 50 00 with a 43'x43' field of view covering the entire rectangular error box by MAXI/GSC. Observations were performed at the zenith distance of 31 degree, only 18 deg from the waxing Moon (phase 0.60). Visual inspection of the combined image (3x60-sec unfiltered exposures) against 1991-06-15 DSS Red plate shows no optical transient to the 3-sigma upper limit of 18.5m (calibrated against USNO-B1.0 Red magnitudes). In particular, there is no new object in the vicinity of the unidentified ROSAT X-ray source 1RXS J174835.3-014843 which falls inside the gamma-ray burst error box.