{
  "bibcode": "2007GCN..6363....1S",
  "body": "R.L.C. Starling, A.P. Beardmore, K.L. Page, P.A. Evans (U. Leicester) and \nJ. Cannizzo (GSFC/UMBC) report on behalf of the Swift XRT team:\n\nWe have analysed Swift XRT data from the first orbit of Windowed Timing\nmode and two subsequent orbits in Photon Counting (PC) mode for GRB\n070429A (trigger 277571, Barthelmy et al. GCN Circ 6355).\n\nUsing 380s of overlapping XRT PC mode data and UVOT V-band data, we\nobtain an astrometrically corrected (using the USNO-B1 catalogue) X-ray\nposition of RA, Dec (J2000) = 297.70333, -32.40497, which is\nRA(J2000) =   19h 50m 48.80s\nDec(J2000) = -32d 24' 17.9\"\nwith an estimated uncertainty of 2.4 arcsec (90% error radius).\nThis is 1.0 arcsec from the XRT position in GCN 6355 and\n1.6 arcsec from the possible K-band optical transient report by\nde Ugarte Postigo et al. (GCN Circ 6361).\n\nThe lightcurve is well fitted by a broken power law with\nalpha1=6.4+0.3/-0.4, Tbreak=235+2/-20 s and alpha2=3.2+0.3/-0.2.\n\nThe PC mode spectrum can be fit with a single absorbed power law. The\nphoton index is 1.8+0.4/-0.2 and the\nabsorption is centred at 1.3E21 cm^-2 but is poorly constrained. The\nGalactic column towards this position is 0.9E21 cm^-2.\nThe 0.3-10 keV flux is 1.25E-11 erg/cm^2/s, corresponding to 0.11\ncts/s.\n\nWe are now in a data gap for this source, whilst Swift is\nobserving GRB 070429B, so the current decay rate\nis not known, hence we do not give a predicted count rate for 24hr.\nFurther Swift observations of this source are planned.\n\nThis circular is an official product of the Swift XRT team.",
  "circularId": 6363,
  "createdOn": 1177863068000,
  "email": "rlcs1@star.le.ac.uk",
  "subject": "GRB 070429A: Swift XRT refined analysis",
  "submitter": "Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>",
  "eventId": "GRB 070429A"
}