TITLE: GCN CIRCULAR NUMBER: 39373 SUBJECT: GRB 250217C: Swift-XRT observations DATE: 25/02/19 13:51:26 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), J.A. Kennea (PSU), D.N. Burrows (PSU), M. A. Williams (PSU), J.P. Osborne (U. Leicester) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the IPN-detected burst GRB 250217C in a series of observations tiled on the sky. The total exposure time is 3.5 ks, distributed over 7 tiles; the maximum exposure at a single sky location in the tiling was 1.2 ks. The data were collected between T0+69.9 ks and T0+98.0 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 ~0.01 to ~0.03 ct s^-1, corresponding to a 0.3-10 keV observed flux of 5.3e-13 to 1.3e-12 erg cm^-2 s^-1 (assuming a typical GRB spectrum). Three previously-catalogued X-ray sources have been detected, however their status as catalogued objects makes them 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 https://www.swift.ac.uk/xrt_products/TILED_GRB00133. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/39373. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...