TITLE: GCN CIRCULAR NUMBER: 12365 SUBJECT: GRB 110918A: INT optical detection of Swift candidate afterglow DATE: 11/09/20 13:53:36 GMT FROM: Nial Tanvir at U.Leicester N.R. Tanvir, K. Wiersema (U. Leicester), A.J. Levan, S. Greiss,  B. Gaensicke (U. Warwick) report on behalf of a larger collaboration:  We observed the field of IPN burst GRB 110918A (Hurley et al. GCN 12357) with the Isaac Newton Telescope on La Palma, using the Wide Field Camera starting at 20-Sep-2011 02:22 UT, roughly 29 hours post-burst.  Close to the location of the X-ray source reported by Mangano et al. (GCN 12364) we detect a bright optical point-source which is not visible in the DSS2 images of the region. Very provisional calibration gives a magnitude R~19.0-19.5 (well above the DSS2 limit) and a position:  RA(2000)=02 10 09.39  dec(2000)=-27 06 19.6  accurate to ~0.5" in each coordinate.  We cannot yet assess variability.