TITLE: GCN CIRCULAR NUMBER: 30379 SUBJECT: GRB 210704A: Swift-XRT afterglow detection DATE: 21/07/05 15:34:15 GMT FROM: Phil Evans at U of Leicester A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 210704A (Berretta et al. GCN Circ. 30375), collecting 2.6 ks of Photon Counting (PC) mode data between T0+53.5 ks and T0+61.1 ks. An uncatalogued X-ray source is detected and is above the 2SXPS 3-sigma upper limit at this position, and is therefore likely the GRB afterglow. Using 2378 s of PC mode data and 2 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 159.02219, +57.21636 which is equivalent to: RA (J2000): 10h 36m 05.33s Dec(J2000): +57d 12' 58.9" with an uncertainty of 3.2 arcsec (radius, 90% confidence). This position is 5.9 arcmin from the Fermi/LAT position. We cannot determine at the present time whether the source is fading. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021454. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021454. This circular is an official product of the Swift-XRT team.