{
  "bibcode": "2007GCN..6114....1S",
  "body": "M. Stamatikos (NASA/ORAU), S. D. Barthelmy (GSFC),\nA. P. Beardmore (U Leicester), D. N. Burrows (PSU),\nN. Gehrels (NASA/GSFC), S. Immler (GSFC/USRA), J. A. Kennea (PSU),\nF. E. Marshall (NASA/GSFC), C. Pagani (PSU),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nT. Sakamoto (NASA/ORAU), P. Schady (MSSL-UCL) and\nD. E. Vanden Berk (PSU) report on behalf of the Swift Team:\n\nAt 04:44:33 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 070220 (trigger=261299).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 34.819, +68.818 which is \n   RA(J2000)  = +02h 19m 17s\n   Dec(J2000) = +68d 49' 06\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows multiple peaks\nwith a duration of about 60 sec.  The peak count rate\nwas ~7000 counts/sec (15-350 keV), at ~15 sec after the trigger. \n\nThe XRT began observing the field at 04:45:51 UT, 79 seconds after the\nBAT trigger. XRT found a bright, fading, uncatalogued X-ray source\nlocated at RA, Dec 34.7765, +68.8052 which is\n   RA(J2000)  =  02h 19m 06.3s\n   Dec(J2000) =  68d 48' 18.7\"\nwith an uncertainty of 4.7 arcseconds (radius, 90% containment). \nThis location is 72 arcseconds from the BAT on-board position,\nwithin the BAT error circle. The initial flux in the 2.5s image\nwas 4.5e-09 erg/cm2/s (0.2-10 keV). \n\nUVOT took a finding chart exposure of 100 seconds with the White\n(160-650 nm) filter starting 88 seconds after the BAT trigger. No\nafterglow candidate has been found in the initial data products. The\n2.7'x2.7' sub-image covers 100% of the XRT error circle. The 3-sigma\nupper limit in a 100s white band exposure is 19.6 mag. The 8'x8'\nregion for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about\n18 mag. No correction has been made for the expected extinction\ncorresponding to E(B-V) of 0.90.",
  "circularId": 6114,
  "createdOn": 1171947913000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 070220: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 070220"
}