TITLE: GCN CIRCULAR NUMBER: 42648 SUBJECT: GRB 251111A: Swift-XRT afterglow detection DATE: 25/11/12 10:51:12 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> S. Campana (INAF-OAB), D.N. Burrows (PSU), S. Lanava (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), 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 GRB 251111A. We searched for X-ray sources in 2.1 ks of Photon Counting (PC) mode data. The total exposure at the position of the afterglow (see below) is 2.1 ks, obtained between T0+7.6 ks and T0+36.9 ks. An uncatalogued X-ray source is detected and is believed to be the afterglow. Using 305 s of PC mode data and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 32.36166, +5.22815 which is equivalent to: RA (J2000): 02h 09m 26.80s Dec(J2000): +05d 13' 41.3" with an uncertainty of 5.1 arcsec (radius, 90% confidence). The observed count rate was 2.5 (+1.2, -0.9)e-02 count/s at T0+7.7 ks, falling to 5.2 (+2.6, -1.9)e-03 at T0+33.8 ks, which indicates the X-ray source is fading. The results of the XRT-team automatic analysis are available at https://www.swift.ac.uk/xrt_products/03000189. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/SVOM/SVOM_FIELD00049. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/42648. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...