GCN Circular 14603
P. D'Avanzo (INAF-OAB), A.Y. Lien (NASA-GSFC), P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: We have analysed 12.3 ks of XRT data for the Fermi-LAT-detected burst GRB 130504C (Kocevski et al. GCn Circ 14574), from 65.6 ks to 278.7 ks after the Fermi-LAT trigger. The data are entirely in Photon Counting (PC) mode. The X-ray source reported by D'Avanzo et al. (GCN Circ. 14584, 14588) displays a fading behaviour. The overall light curve can be modelled with a power-law decay with a decay index of alpha=1.39 (+0.32, -0.25). We confirm it as the X-ray afterglow of GRB 130504C. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020267.