{
  "bibcode": "2014GCN.15915....1E",
  "body": "P. A. Evans (U Leicester), A. P. Beardmore (U Leicester),\nD. N. Burrows (PSU), N. Gehrels (NASA/GSFC), S. T. Holland (STScI),\nJ. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),\nC. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),\nA. Maselli (INAF-IASFPA), K. L. Page (U Leicester),\nD. M. Palmer (LANL), T. Sakamoto (AGU), M. H. Siegel (PSU) and\nT. N. Ukwatta (MSU) report on behalf of the Swift Team:\n\nAt 13:22:31 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 140304A (trigger=590206).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 30.668, +33.485 which is \n   RA(J2000) = 02h 02m 40s\n   Dec(J2000) = +33d 29' 07\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a multi-peaked\nstructure with a total duration of about 20 sec.  The peak count rate\nwas ~3600 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 13:23:46.2 UT, 75.2 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nuncatalogued X-ray source with an enhanced position: RA, Dec 30.6412,\n33.4744 which is equivalent to:\n   RA(J2000)  = 02h 02m 33.90s\n   Dec(J2000) = +33d 28' 27.9\"\nwith an uncertainty of 2.2 arcseconds (radius, 90% containment). This\nlocation is 89 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at http://www.swift.ac.uk/sper. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of 5.98\nx 10^20 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 2.5 s image was 6.28e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 250 seconds with the U filter starting\n137 seconds after the BAT trigger. No credible afterglow candidate has been\nfound in the initial data products. The 2.7'x2.7' sub-image processing FAILED\nbecause of no aspect solution. Results from the list of sources generated\non-board are not available at this time. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.08. \n\nThis GRB will enter a Moon observing constraint around 20:00 UT and\nwill not be observable again by Swift until March 6 (Thursday) around\n05:30 UT. \n\nBurst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). \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": 15915,
  "createdOn": 1393941435000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 140304A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 140304A"
}