{
  "bibcode": "2007GCN..6520....1P",
  "body": "C. Pagani (PSU), C. B. Markwardt (CRESST/U.Md./GSFC), P. Evans (U. Leicester), \nF. Gavriil (NPP/GSFC), J. A. Kennea (PSU), A. D. Falcone (PSU), W. Landsman \n(NASA/GSFC) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift \nTeam:\n\nWe report on the continued SWIFT observations of the BAT trigger 281993, \noriginally designated GRB 070610.\n \nWe have collected 13.2 ks of XRT Photon Counting data in the T+3.1 ks to T+122 \nks time interval.  The X-ray light curve shows evidence of rapid variability, \nwith intense flaring activity and a possible late rebrightening.\nUnlike a typical GRB afterglow, the lightcurve has shown no evidence of \noverall fading.\n\nWe can exclude at this point a GRB afterglow origin of the counterpart \nobserved by the narrow field instruments.  The BAT trigger 281993 is probably \na Galactic X-ray Transient, but we can not completely discard the possibility \nof a GRB origin with an undetected X-ray counterpart.\nIn particular, an undetected afterglow from a short GRB (the T90 for \nthis trigger is 4.6 sec, GCN Circ. 6491) would not be unusual considering the \nXRT observations started at T+3.1 ks.  The flaring behavior reported by \nground based observations (GCN Circ. 6492, GCN Circ. 6501, GCN Circ. 6505, \nGCN Circ. 6508) also favors the fast X-ray transient origin of the \ncounterpart. For additional details on the interpretations on the origin of \nthe source, refer to Markwardt et al. ATEL #1102.\n\nThe X-ray spectrum of the PC data in the T+3.1 ks to T+122 ks time interval, \nmodeled with an absorbed power law, gives a photon index of 1.8+/-0.3 with the \ntotal column density consistent with the Galactic value of 1.01e22 cm**-2. \nThe absorbed (unabsorbed) 0.3-10.0keV average flux in the T+3.1 ks - T+122 ks \ntime interval is 2.4E-12 (3.9E-12) ergs cm^-2 s^-1.\n\nWe also note that in the XRT field of view we detect an additional X-ray \nsource 4.3 arcmin from the BAT refined position (and outside of the BAT 1.8 \narcmin 90% error circle) that is most probably an X-ray active star.  The \nanalysis of this source (designated SWIFT J195456.7+261301) will be reported \nin a separate ATEL.",
  "circularId": 6520,
  "createdOn": 1181664128000,
  "email": "pagani@astro.psu.edu",
  "subject": "SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations",
  "submitter": "Claudio Pagani at PSU/Swift-XRT  <pagani@astro.psu.edu>",
  "eventId": "GRB 070610"
}