{
  "bibcode": "2017GCN.21261....1E",
  "body": "S. W. K Emery (UCL-MSSL), P. A. Evans (U Leicester),\nA. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester) and\nB. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:\n\nAt 10:32:44 UT, the Swift Burst Alert Telescope (BAT) triggered on noise\nnear NGC5949 (trigger=758168).  Swift slewed immediately to the location. \nThe BAT on-board calculated location is \nRA, Dec 232.221, +64.871 which is \n   RA(J2000) = 15h 28m 53s\n   Dec(J2000) = +64d 52' 14\"\nwith an uncertainty of 4 arcmin (radius, 90% containment, including \nsystematic uncertainty). As is typical for image triggers, \nthere is nothing in the real-time light curve. \n\nThe XRT began observing the field at 10:39:26.2 UT, 401.6 seconds after\nthe BAT trigger. No source was detected in 391 s of promptly downlinked\ndata. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 404 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 expected extinction corresponding to E(B-V) of\n0.03. \n\nGiven that this is a low significance detection in BAT (5.9 sigma) and that there is\nno XRT source, we think this is a non-astrophysical fluctuation in the BAT image\nthat happens to be close the NGC5949 source.",
  "circularId": 21261,
  "createdOn": 1498128714000,
  "email": "klp5@leicester.ac.uk",
  "subject": "Swift trigger 758168 is probably not an astrophysical source",
  "submitter": "Kim Page at U.of Leicester  <klp5@leicester.ac.uk>"
}