TITLE: GCN CIRCULAR NUMBER: 8818 SUBJECT: GRB090117: Swift-XRT detection of a possible candidate afterglow DATE: 09/01/18 00:04:10 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team : The Swift-XRT began observing the field of the SuperAGILE GRB 090117 at 2009-01-17 19:10:13 UT, 13.7 ks after the burst. In a 1.9 ks Photon Counting mode X-ray image covering the 0.3-10 keV band, we detect an uncatalogued source within the SuperAGILE error circle at the astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) of RA, Dec = 164.0444, -58.2336 which is equivalent to: RA (J2000): 10 56 10.66 Dec (J2000): -58 14 00.8 with an uncertainty of 2.4 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. The position enhancement is described by Goad et al. (2007, A&A, 476, 1401 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method. At this stage we cannot tell if the source is fading to confirm that it is the X-ray counterpart of the SuperAGILE burst. This circular is an official product of the Swift-XRT team.