TITLE: GCN CIRCULAR NUMBER: 30234 SUBJECT: GRB 210605B: Swift-XRT afterglow detection DATE: 21/06/14 14:06:06 GMT FROM: Aaron Tohuvavohu at U Toronto A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), 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 conducted further observations of the field of the Swift/BAT-GUANO detected burst GRB 210605B (James DeLaunay et al. GCN Circ. 30130). The observations now extend from T0+74.3 ks to T0+734.1 ks. Of the sources reported by D'Ai et al. (GCN Circ. 30146), "Source 1" is fading with 2.5 sigma significance and thus is believed to be the GRB afterglow. The position of this source is RA, Dec=15.7456, -6.4290 which is equivalent to: RA (J2000): 01:02:58.95 Dec(J2000): -06:25:44.3 with an uncertainty of 5.7 arcsec (radius, 90% confidence). This position is 2.4 arcmin from the Swift/BAT position. The light curve can be modelled with a power-law decay with a decay index of alpha=0.8 (+0.7, -0.4). The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021450. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021450. This circular is an official product of the Swift-XRT team.