TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4284 SUBJECT: GRB 051117B: Optical observations DATE: 05/11/17 17:23:53 GMT FROM: Derek Fox at PSU D.B. Fox (Penn State) and R.H. McNaught (RSAA/ANU, SSO) report on behalf of a larger colloboration: "We have observed the Swift localization region for GRB 051117B (Band et al., GCN 4281) with the 40-inch telescope at Siding Spring Observatory, in a series of unfiltered exposures beginning at 14:12 UT (49 minutes after the burst). A coadded exposure at mean epoch 14:16 UT reveals no source coincident with the XRT position (Beardmore et al., GCN 4282), nor any new sources within the BAT localization region by comparison to the DSS. We estimate our limiting magnitude for this image to be R=18.8 mag by comparison to the USNO-B1.0 catalog R-band magnitudes of nearby stars." [GCN_OPS_NOTE(17nov05): per author's request the author list was added.]