{
  "bibcode": "2017GCN.21047....1E",
  "body": "A.P. Beardmore\tand  P.A. Evans (U. Leicester)\treport on behalf of the\nSwift-XRT team:\n\nWe have analysed 4.2 ks of XRT data for GRB 170428A, from 697 s to 17.2\nks after the  BAT trigger. The data are entirely in Photon Counting\n(PC) mode. Using 1475 s of PC mode data and 2 UVOT images, we find an\nenhanced XRT position (using the XRT-UVOT alignment and matching UVOT\nfield sources to the USNO-B1 catalogue): RA, Dec = 330.07813, +26.91580\nwhich is equivalent to:\n\nRA (J2000): 22h 00m 18.75s\nDec(J2000): +26d 54' 56.9\"\n\nwith an uncertainty of 2.3 arcsec (radius, 90% confidence).\n\nThe light curve can be modelled with a power-law decay with a decay\nindex of alpha=1.03 (+0.32, -0.29).\n\nIf the light curve continues to decay with a power-law decay index of\n1.03, the count rate at T+24 hours will be 7.5 x 10^-4 count s^-1\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00750298.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 21047,
  "createdOn": 1493414372000,
  "email": "ab271@leicester.ac.uk",
  "subject": "GRB 170428A: Swift-XRT refined Analysis",
  "submitter": "Andy Beardmore at U Leicester  <ab271@leicester.ac.uk>",
  "eventId": "GRB 170428A"
}