TITLE: GCN CIRCULAR NUMBER: 17723 SUBJECT: GRB 150413A: Swift-XRT observations DATE: 15/04/20 09:26:50 GMT FROM: Claudio Pagani at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), D.N. Burrows (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and C. B. Markwardt (NASA/GSFC) report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for the Swift/BAT-detected burst GRB 150413A (Markwardt et al., GCN Circ. 17688). The data are entirely in Photon Counting (PC) mode, collected between T0+303.3 ks and T0+550.9 ks. No X-ray sources have been detected inside or close to the Swift/BAT error region. The 3-sigma upper limit at the position of the optical afterglow (Ivanov et al., GCN Circ. 17689) is 0.003 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.2e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). 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/00637899. This circular is an official product of the Swift-XRT team.