TITLE: GCN CIRCULAR NUMBER: 43558 SUBJECT: GRB 260127B: Swift-XRT observations DATE: 26/01/29 15:59:58 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> D.N. Burrows (PSU), S. Lanava (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), S. Campana (INAF-OAB), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/GBM-detected burst GRB 260127B (The Fermi GBM team, GCN Circ. 43533), collecting 985 s of Photon Counting (PC) mode data between T0+70.4 ks and T0+71.4 ks. No X-ray sources have been detected consistent with the tentative GOTO optical afterglow candidate (O’Neill et al, GCN Circ. 43538). The 3-sigma upper limit in the field ranges from ~0.01 to ~0.02 ct s^-1, corresponding to a 0.3-10 keV observed flux of 5.0e-13 to 6.9e-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 https://www.swift.ac.uk/ToO_GRBs/00021900. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/43558. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...