TITLE: GCN CIRCULAR NUMBER: 18069 SUBJECT: GRB 150724B: Swift-XRT observations DATE: 15/07/26 05:24:25 GMT FROM: Kim Page at U.of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), V. D'Elia (ASDC), A. D'ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) 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 150724B (Bissaldi et al. GCN Circ. 18065), collecting 1.8 ks of Photon Counting (PC) mode data between T0+94.4 ks and T0+96.2 ks. One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 1: RA (J2000.0): 351.8904 = 23:27:33.70 Dec (J2000.0): +3.8186 = +03:49:06.8 Error: 4.3 arcsec (radius, 90% conf.) Count-rate: 0.0143 +/- 0.0033 ct s^-1 Flux: (4.6 +/- 1.1)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020543. This circular is an official product of the Swift-XRT team.