{
  "bibcode": "2016GCN.20276....1D",
  "body": "V. D'Elia (ASDC), J. A. Kennea (PSU), H. A. Krimm (CRESST/NSF/USRA),\nA. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL) and T. Sakamoto (AGU) report on behalf of the\nSwift Team:\n\nAt 01:27:34 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 161217A (trigger=727167).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is RA, Dec 150.637, +52.389 which is \n   RA(J2000) = 10h 02m 33s\n   Dec(J2000) = +52d 23' 21\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a peak starting\naround T+35s and lasting about 15 seconds.  (Because this was\nan image trigger, the 'trigger time' is not tightly synchronized to\nthe time of the rate increase.)  The peak count rate\nwas ~600 counts/sec (15-350 keV), at ~35 sec after the trigger. \n\nThe XRT began observing the field at 01:30:15.5 UT, 160.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 150.6517, 52.3592 which\nis equivalent to:\n   RA(J2000)  = 10h 02m 36.40s\n   Dec(J2000) = +52d 21' 33.1\"\nwith an uncertainty of 2.4 arcseconds (radius, 90% containment). This\nlocation is 112 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttp://www.swift.ac.uk/sper.  We cannot determine whether the source is\nfading at the present time. No spectrum from the promptly downlinked\nevent data is yet available to determine the column density. \n\nUVOT took a finding chart exposure of 144 seconds with the White filter\nstarting 163 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 none of\nthe XRT error circle. The 8'x8' region for the list of sources generated\non-board covers 100% of the XRT error circle. The list of sources is typically\ncomplete to about 18 mag. No correction has been made for the expected\nextinction corresponding to E(B-V) of 0.01. \n\nBurst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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": 20276,
  "createdOn": 1481939687000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 161217A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 161217A"
}