TITLE: GCN CIRCULAR NUMBER: 17409 SUBJECT: GRB 150204A: Swift-XRT observations DATE: 15/02/05 15:31:28 GMT FROM: Boris Sbarufatti at INAF-OAB/IASFPA A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), 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-detected burst GRB 150204A (Cummings et al. GCN Circ. 17404), collecting 4.4 ks of Photon Counting (PC) mode data between T0+51.2 ks and T0+63.6 ks. One uncatalogued X-ray source has been detected inside or close to the Swift/BAT error region, 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 2: RA (J2000.0): 160.2373 = 10:40:56.94 Dec (J2000.0): -64.0387 = -64:02:19.4 Error: 4.8 arcsec (radius, 90% conf.) Count-rate: (8.9 +/- 1.8)e-3 ct s^-1 Flux: (3.69 +/- 0.75)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/00020477. This circular is an official product of the Swift-XRT team.