{
  "bibcode": "2014GCN.16707....1C",
  "body": "J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),\nD. Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC) and\nB. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:\n\nAt 17:10:03 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated a source consistent with the position of SAX J1712.6-3739\n(trigger=609878).  Swift slewed immediately to the location. \nThe BAT on-board calculated location is \nRA, Dec 258.161, -37.657 which is \n   RA(J2000) = 17h 12m 39s\n   Dec(J2000) = -37d 39' 22\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a ~10-second peak at ~T+130.  \nThis was a 332-second image trigger.  BAT retriggered on the same source \nwith the next 320-second image trigger attempt (trigger=609879), with a \nhigher flux.  The lightcurve shows rapid fluctuations.  The peak count \nrate was ~200 counts/sec (15-350 keV), at 130 sec after the trigger. \n\nThe XRT began observing the field at 17:16:59.4 UT, 415.8 seconds after\nthe BAT trigger. XRT found a bright X-ray source located at RA, Dec\n258.1547, -37.6444 which is equivalent to:\n   RA(J2000)  = +17h 12m 37.13s\n   Dec(J2000) = -37d 38' 39.8\"\nwith an uncertainty of 4.7 arcseconds (radius, 90% containment). This\nlocation is 48 arcseconds from the BAT onboard position, within the BAT\nerror circle. This is 4.5 arcseconds away from the position of SAX J1712.6-3739\n(Wiersema et al. 2009, MNRAS 397, 6). This source is in the Swift XRT 1SXPS\ncatalogue as 1SXPS J171236.9-373842 with a mean 0.3-10 keV count-rate of \n3.830 +/- 0.033 ct/sec; see http://www.swift.ac.uk/1SXPS/1SXPSJ171236.9-373842 \nfor details of these previous observations. No event data are yet available to\ndetermine the column density using X-ray spectroscopy. \n\nThe initial flux in the 2.5 s image was 1.69e-08 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White\nfilter  starting 425 seconds after the BAT trigger. No credible\nafterglow candidate has  been found in the initial data products. The\n2.7'x2.7' sub-image covers 100% of  the XRT error circle. The typical\n3-sigma upper limit has been about 19.6 mag.   The 8'x8' region for\nthe list of sources generated on-board covers   100% of the XRT error\ncircle.  The list of sources is typically complete to about 18 mag.  \nWe note that this is a crowded field with large expected  extinction. \nNo correction has been made for the large, but uncertain extinction \nexpected. \n\nThis source has been detected by BAT many times, with the most recent\non-board detection in 2014 May, and it is variable but persistently\nvisible in BAT ground analysis.",
  "circularId": 16707,
  "createdOn": 1408384709000,
  "email": "palmer@lanl.gov",
  "subject": "Swift detection of SAX J1712.6-3739",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}