{
  "bibcode": "2010GCN.10737....1S",
  "body": "B. Sbarufatti (INAF-OAB/IASFPA), W. H. Baumgartner (GSFC/UMBC),\nD. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),\nP. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),\nJ. M. Gelbord (PSU), C. Guidorzi (U Ferrara),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB),\nR. Margutti (INAF-OAB), P. T. O'Brien (U Leicester),\nJ. P. Osborne (U Leicester), K. L. Page (U Leicester),\nD. M. Palmer (LANL), P. Romano (INAF-IASFPA),\nA. Rowlinson (U Leicester), M. H. Siegel (PSU), M. A. Stark (PSU) and\nL. Vetere (PSU) report on behalf of the Swift Team:  \n\nAt 11:50:39 UT, the Swift Burst Alert Telescope (BAT) triggered\non trigger=421695.  Swift slewed immediately to the location.\nThe BAT on-board calculated location is\nRA, Dec 280.612, +18.328 which is\n   RA(J2000) = 18h 42m 27s\n   Dec(J2000) = +18d 19' 40\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including\nsystematic uncertainty).  The onboard significance is low (~6.5 sigma)\nin both the rate and image domains. Also the initial BAT light curve\ndoes not show any significant peaks, so we do not believe that this\nis a real burst.\n\nThe XRT began observing the field at 11:51:50.7 UT, 71.7 seconds after\nthe BAT trigger. No source was detected in the promptly available XRT\ndata. We are waiting for the full dataset to detect and localise any\nXRT counterpart.\n\nUVOT took a finding chart exposure of 150 seconds with the White\nfilter starting 75 seconds after the BAT trigger. No credible\nafterglow candidate has been found in the initial data products.\nBecause part of the 2.7'x2.7' sub-image was not received, the overlap  \nwith the BAT error circle is uncertain. The overlap is at most 25%.\nThe coverage of the BAT error circle by the 8'x8' region for the list\nof sources generated on-board is uncertain because the large number of\nsources filled the available telemetry. No correction has been made\nfor the expected extinction corresponding to E(B-V) of 0.33.\n\nDue to the marginal detection of this event in BAT, and the lack\nof a detection in the early XRT data, we believe that this is\nprobably not a real astrophysical event.  Further determination\nof its reality will require analysis of the ground-linked data\nafter ~17:00 UT.\n\nBurst Advocate for this burst is B. Sbarufatti (sbarufatti AT ifc.inaf.it).\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": 10737,
  "createdOn": 1273587612000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "Trigger 421695: Swift detection of a possible burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>"
}