TITLE: GCN CIRCULAR NUMBER: 7699 SUBJECT: GRB 080507: Swift-XRT position of a possible afterglow DATE: 08/05/08 18:25:00 GMT FROM: Vanessa Mangano at INAF-IASFPA V. Mangano, B. Sbarufatti (INAF-IASF PA), J. Kennea (PSU), and W. H. Baumgartner (GSFC/UMBC) report on behalf of the Swift-XRT team: Swift started a ToO observation of GRB 080507 (Lapshov et al., GCN Circ. 7697) today at 14:05 UT. We have analysed the first 2.5 ks of PC data and found a bright uncatalogued source at RA, Dec = 233.68085, 56.43520 which is equivalent to: RA (J2000): 15 34 43.40 Dec (J2000): +56 26 06.7 with an uncertainty of 2.5 arcsec (radius, 90% confidence; astrometrically corrected X-ray position). This is 90 arcsec from the SuperAGILE position. We also found a second uncatalogued faint source at RA, Dec = 233.662500, 56.420972 (118 arcsec from the SuperAGILE position) and a third faint source at RA, Dec = 233.612083, 56.428500 (217 arcsec from the SuperAGILE potition), likely the counterpart of SDSS J153426.68+562545.8. At the moment data are not enough to say if these sources are fading. This is an official product of the Swift-XRT team