{
  "bibcode": "2012GCN.13238....1B",
  "body": "S. D. Barthelmy (GSFC), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB),\nN. Gehrels (NASA/GSFC), S. T. Holland (STScI), E. A. Hoversten (PSU),\nJ. A. Kennea (PSU), A. Y. Lien (NASA/GSFC/ORAU),\nF. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),\nD. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU), C. A. Swenson (PSU)\nand B.-B. Zhang (PSU) report on behalf of the Swift Team:\n\nAt 01:16:39 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated a marginal peak (6.51 sigma) in the resulting image\n(trigger=519874).  Swift slewed immediately to the location. \nThe BAT on-board calculated location is \nRA, Dec 35.550, +59.746 which is \n   RA(J2000) = 02h 22m 12s\n   Dec(J2000) = +59d 44' 46\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows nothing significant\nat the time of the trigger. \n\nThe XRT began observing the field at 01:18:11.4 UT, 92.5 seconds after\nthe BAT trigger. No source was detected in 218 s of promptly downlinked\ndata. We are waiting for the full dataset to detect and localise the\nXRT counterpart. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 95 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers 25% of\nthe BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nBAT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the large, but uncertain extinction expected. \n\nDue to the marginal nature of the BAT detection, and the lack\nof any detection by XRT and UVOT despite the prompt slew,\nwe believe that this event was most likely a statistical\nfluctuation and not an astrophysical source.",
  "circularId": 13238,
  "createdOn": 1334107904000,
  "email": "palmer@lanl.gov",
  "subject": "Swift Trigger 519874 is probably a noise event",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}