TITLE: GCN CIRCULAR NUMBER: 17684 SUBJECT: GRB 150407A: Swift-XRT observations DATE: 15/04/08 07:39:54 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A. Amaral-Rogers (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU) 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 150407A (Palmer et al. GCN Circ. 17682), collecting 2.0 ks of Photon Counting (PC) mode data between T0+68.5 ks and T0+70.5 ks. No X-ray sources have been detected inside or close to the Swift/BAT error region. The 3-sigma upper limit in the field ranges from ~0.004 to ~0.009 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.4e-13 to 3.8e-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/00020487. This circular is an official product of the Swift-XRT team.