{
  "bibcode": "2008GCN..7442....1P",
  "body": "C. Pagani (PSU), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),\nD. N. Burrows (PSU), P. A. Evans (U Leicester),\nN. Gehrels (NASA/GSFC), O. Godet (U Leicester),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nV. Mangano (INAF-IASFPA), J. P. Osborne (U Leicester),\nK. L. Page (U Leicester), A. M. Parsons (GSFC), J. L. Racusin (PSU),\nB. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU),\nR. L. C. Starling (U Leicester), G. Stratta (ASDC) and\nT. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:\n\nAt 12:25:56 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 080319C (trigger=306778).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 258.973, +55.410 which is \n   RA(J2000)  =  17h 15m 54s\n   Dec(J2000) = +55d 24' 35\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows several overlapping FRED-like\npeaks starting at T+0 and ending around T+20 sec.  The peak count rate\nwas ~8000 counts/sec (15-350 keV), at ~T+0 sec after the trigger. \n\nThe XRT began observing the field at 12:29:40 UT, 224 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 258.9828, 55.3920\nwhich is equivalent to:\n   RA(J2000)  = 17h 15m 55.86s\n   Dec(J2000) = +55d 23' 31.2\"\nwith an uncertainty of 4.5 arcseconds (radius, 90% containment). This\nlocation is 3 arcseconds from the optical afterglow candidate position. \n\nUVOT took a finding chart exposure of 100 seconds with the White   \n(160-650 nm) filter starting 227 seconds after the BAT trigger. There\nis a candidate afterglow in the rapidly available 2.7'x2.7' \nsub-image at   \n\n  RA(J2000)  =\t17:15:55.51 = 258.9813   \n  DEC(J2000) = +55:23:30.8  = +55.3919    \n\nwith a 1-sigma error radius of  about 0.5 arc sec. This position\nis 67.4 arc sec. from the center of  the BAT error circle.  This\nis consistent with the KAIT position (Li  et al., 2008, GCNC 7441). \nThe estimated magnitude is white = 18.8 with a  1-sigma  error of\nabout 0.5 mag. No correction has been  made for the  expected\nextinction corresponding to E(B-V) of 0.03. \n\nBurst Advocate for this burst is C. Pagani (pagani AT astro.psu.edu). \nPlease contact the BA by email if you require additional information\nregarding Swift followup of this burst. In extremely urgent cases, after\ntrying the Burst Advocate, you can contact the Swift PI by phone (see\nSwift TOO web site for information: http://www.swift.psu.edu/too.html.)",
  "circularId": 7442,
  "createdOn": 1205930758000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 080319C: Swift detection of a burst with an optical afterglow",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 080319C"
}