{
  "bibcode": "2012GCN.13299....1B",
  "body": "S. D. Barthelmy (GSFC), D. N. Burrows (PSU), V. D'Elia (ASDC),\nN. Gehrels (NASA/GSFC), B. Gendre (ASDC), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), V. Mangano (INAF-IASFPA),\nC. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),\nA. Maselli (INAF-IASFPA), D. M. Palmer (LANL),\nP. Romano (INAF-IASFPA), C. J. Saxton (UCL-MSSL),\nB. Sbarufatti (INAF-OAB/PSU), M. C. Stroh (PSU) and B.-B. Zhang (PSU)\nreport on behalf of the Swift Team:\n\nAs part of a campaign to detect faint nearby GRBs, BAT has lowered its\nthreshold to events near to known sources and nearby Galaxies. \n\nAt 16:53:59 UT, the Swift Burst Alert Telescope (BAT) triggered at this lower\nthreshold in the vicinity of the known source IGR J17091-3624.  Swift slewed\nimmediately to the location.  The BAT on-board calculated location is \nRA, Dec 257.313, -36.282 which is \n   RA(J2000)  =  17h 09m 15s\n   Dec(J2000) = -36d 16' 56\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As is usual for image triggers, the immediately\navailable lightcurve show no obvious variation. \n\nThe XRT began observing the field at 16:56:02.5 UT, 122.7 seconds after\nthe BAT trigger. No source was detected in central 8x8 arcminute window \nin 641 s of promptly downlinked data.  IGR J17091-3624 is outside of this\npromptly downlinked window. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter starting\n127 seconds after the BAT trigger. No credible new source has been found in\nthe initial data products. The 8'x8' region for the list of sources generated\non board covers 100% of the BAT error circle, but not the IGR J17091-3624\nsource. The list of sources is typically complete to about 18 mag. \n\nGiven the marginal significance of the BAT detection (5.84 sigma)\nthe distance of the BAT detection from the known source location \n(7.5 arcmin) and the lack of detection by the narrow field instruments,\nwe believe that this is not a true detection of an astrophysical source.",
  "circularId": 13299,
  "createdOn": 1337016223000,
  "email": "palmer@lanl.gov",
  "subject": "Swift Trigger 522245 is a noise fluctuation near IGR J17091-3624",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}