{
  "bibcode": "2016GCN.19014....1T",
  "body": "E. Troja (NASA/GSFC/UMCP), S. D. Barthelmy (GSFC),\nD. N. Burrows (PSU), S. B. Cenko (GSFC), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),\nL. M. McCauley (PSU), T. G. R. Roegiers (PSU),\nB. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf\nof the Swift Team:\n\nAt 19:10:31 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 160216A (trigger=673978).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 311.706, -71.555 which is \n   RA(J2000)  =  20h 46m 49s\n   Dec(J2000) = -71d 33' 17\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows several bright peaks\nwith a duration of about 30 sec.  The peak count rate\nwas ~7000 counts/sec (15-350 keV), at ~3 sec after the trigger. \n\nThe XRT began observing the field at 19:12:05.3 UT, 93.9 seconds after\nthe BAT trigger. The position determined from promptly downlinked data\ndiffers significantly from the on-board position, suggesting that the\nXRT may have centroided on a cosmic ray; the initial XRT position\nnotice should be treated with caution. Using promptly downlinked data\nwe find a fading, uncatalogued X-ray source located at RA, Dec\n311.68630, -71.54787 which is equivalent to:\n   RA(J2000)  = 20h 46m 44.71s\n   Dec(J2000) = -71d 32' 52.3\"\nwith an uncertainty of 3.9 arcseconds (radius, 90% containment). This\nlocation is 34 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at http://www.swift.ac.uk/sper. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (4.50 x\n10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.1\n(+0.67/-0.50) x 10^22 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 100 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 100% of\nthe XRT 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\nXRT 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\n0.05. \n\nBurst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). \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": 19014,
  "createdOn": 1455650601000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 160216A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 160216A"
}