TITLE: GCN CIRCULAR NUMBER: 30399 SUBJECT: GRB 210706A: Swift-XRT afterglow detection DATE: 21/07/07 01:18:21 GMT FROM: Aaron Tohuvavohu at U Toronto A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (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 Swift/BAT-GUANO-detected burst GRB 210706A (Tohuvavohu et al. GCN Circ. 30393), collecting 2.8 ks of Photon Counting (PC) mode data between T0+43.3 ks and T0+50.7 ks. Two uncatalogued X-ray sources are detected, of which one ("Source 2") is believed to be the afterglow. Using 2536 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 = 311.99471, +13.31694 which is equivalent to: RA (J2000): 20h 47m 58.73s Dec(J2000): +13d 19' 01.0" with an uncertainty of 3.2 arcsec (radius, 90% confidence). This position is 69 arcsec from the Swift/BAT-GUANO position. The source has a mean count rate of 1.4e-02 ct/sec; we cannot determine at the present time whether it is fading. The field has been previously observed by XRT for the Swift Gravitational Wave Galaxy Survey (https://www.swift.ac.uk/SGWGS/, GCN 24305). No source was detected at this position on a 2.8 ks integrated exposure, down to a 3-σ upper limit of 7 e-3 ct s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021455. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021455. This circular is an official product of the Swift-XRT team.