TITLE: GCN CIRCULAR NUMBER: 17453 SUBJECT: GRB 150210A: Swift-XRT observations DATE: 15/02/12 12:12:53 GMT FROM: Rhaana Starling at U of Leicester V. Mangano (PSU), M.C. Stroh (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U. Leicester), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), 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 Fermi/LAT-detected burst GRB 150210A (Zhu et al. GCN Circ. 17438) in a series of observations tiled on the sky. The total exposure time is 7.3 ks, distributed over 4 tiles; the maximum exposure at a single sky location was 4.3 ks. The data were collected between T0+66.9 ks and T0+95.4 ks, and are entirely in Photon Counting (PC) mode. No uncatalogued X-ray sources have been detected. The 3-sigma upper limit in the field (not including the regions where the tiles overlap) ranges from ~0.004 to ~0.008 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.5e-13 to 3.3e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). A previously-catalogued X-ray source has been detected, however because it is a catalogued object it is unlikely to be the afterglow. The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/xrt_products/TILED_GRB00040. This circular is an official product of the Swift-XRT team.