TITLE: GCN CIRCULAR NUMBER: 22931 SUBJECT: GRB 180703A: Swift-XRT afterglow detection DATE: 18/07/09 13:33:20 GMT FROM: Antonino D'Ai at IASF-PA S.L. Gibson (U. Leicester), Z. Liu (NAOC / U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has conducted further observations of the field of the Fermi/LAT-detected burst GRB 180703A (Racusin et al. GCN Circ. 22883). The observations now extend from T0+17.3 ks to T0+263.7 ks. The source previously reported by Gibson et al. (GCN Circ. 22891), "Source 1", is believed to be the afterglow. The position of this source is RA, Dec=6.4699, -67.1802 which is equivalent to: RA (J2000): 00:25:52.79 Dec(J2000): -67:10:48.7 with an uncertainty of 4.8 arcsec (radius, 90% confidence). This position is 5.7 arcmin from the Fermi/LAT position. The source is fading with alpha >0.8. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020797. The results of the full analysis of the tiled XRT observations are available at http://www.swift.ac.uk/xrt_products/TILED_GRB00070. This circular is an official product of the Swift-XRT team.