{
  "bibcode": "2012GCN.13843....1B",
  "body": "S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),\nC. B. Markwardt (NASA/GSFC) and M. H. Siegel (PSU) report on behalf of\nthe Swift Team:\n\nAt 23:57:42 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated trigger 535733.  Swift slewed immediately to the location. \nThe BAT on-board calculated location is \nRA, Dec 277.193, -10.479 which is \n   RA(J2000) = 18h 28m 46s\n   Dec(J2000) = -10d 28' 42\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  As typical for image triggers (64-sec), the prompt\nlightcurve data shows nothing significant.  This position is marginally\nconsistent with the known source SAX J1828.5-1037.  We note that the \ndetection significance is marginal as well. \n\nThe XRT began observing the field at 23:59:42.7 UT, 120.5 seconds after\nthe BAT trigger. No source was detected in the 2.5-s promptly available\nimage. We are waiting for the full dataset to detect and localise the\nXRT counterpart. \n\nUVOT took a finding chart exposure of\t6 seconds with the White filter\nstarting 123 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. \nResults from the list of sources generated on-board are not available at this\ntime. No correction has been made for the large, but uncertain extinction\nexpected.",
  "circularId": 13843,
  "createdOn": 1349914681000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "Trigger 535733: Swift possible detection of SAX J1828.5-1037",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>"
}