TITLE: GCN CIRCULAR NUMBER: 20477 SUBJECT: GRB 170115B: Swift-XRT observations DATE: 17/01/17 09:15:10 GMT FROM: Sarah Gibson at U.of Leicester P. D'Avanzo (INAF-OAB), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) 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 170115B in a series of observations tiled on the sky. The total exposure time is 4.7 ks, distributed over 5 tiles; the maximum exposure at a single sky location was 3.3 ks. The data were collected between T0+54.5 ks and T0+66.3 ks, and are entirely in Photon Counting (PC) mode. One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 1: RA (J2000.0): 189.0597 = 12:36:14.34 Dec (J2000.0): -46.8311 = -46:49:52.1 Error: 6.5 arcsec (radius, 90% conf.) Count-rate: 0.0117 +/- 0.0029 ct s^-1 Distance: 163 arcsec from Fermi/LAT position. 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_GRB00062. This circular is an official product of the Swift-XRT team.