GCN Circular 21047
A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: We have analysed 4.2 ks of XRT data for GRB 170428A, from 697 s to 17.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. Using 1475 s of PC mode data and 2 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 330.07813, +26.91580 which is equivalent to: RA (J2000): 22h 00m 18.75s Dec(J2000): +26d 54' 56.9" with an uncertainty of 2.3 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.03 (+0.32, -0.29). If the light curve continues to decay with a power-law decay index of 1.03, the count rate at T+24 hours will be 7.5 x 10^-4 count s^-1 The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00750298. This circular is an official product of the Swift-XRT team.