{
  "bibcode": "2007GCN..6355....1B",
  "body": "S. D. Barthelmy (GSFC), C. B. Markwardt (GSFC/UMD),\nK. L. Page (U Leicester), D. M. Palmer (LANL), G. Sato (GSFC/ISAS),\nM. Stamatikos (NASA/ORAU) and R. L. C. Starling (U Leicester) report\non behalf of the Swift Team:\n\nAt 01:35:10 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 070429 (trigger=277571).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 297.687, -32.388 which is \n   RA(J2000)  =  19h 50m 45s\n   Dec(J2000) = -32d 23' 16\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is typical for image trigger GRBs,\nthe BAT light curve shows little obvious variation.  A detailed\nlight curve will require the data downlinked via Malindi. \n\nThe XRT began observing the field at 01:37:42 UT, 153 seconds after the\nBAT trigger. XRT found a fading, uncatalogued X-ray source\nlocated at RA, Dec 297.7034, -32.4052 which is\n   RA(J2000)  =  19h 50m 48.8s\n   Dec(J2000) = -32d 24' 18.7\"\nwith an uncertainty of 4.7 arcseconds (radius, 90% containment). \nThis location is 79 arcseconds from the BAT on-board position,\nwithin the BAT error circle. The initial flux in the 2.5s image\nwas 2.9e-09 erg/cm2/s (0.2-10 keV). \n\nUVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)\nfilter starting 161 seconds after the BAT trigger. No afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 18.5 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.17 magnitudes.",
  "circularId": 6355,
  "createdOn": 1177811487000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 070429: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 070429"
}