{
  "bibcode": "2016GCN.19926....1R",
  "body": "J. L. Racusin (NASA/GSFC), S. D. Barthelmy (GSFC),\nJ. R. Cummings (NASA/UMBC), J. A. Kennea (PSU),\nD. Malesani (DARK/NBI and DTU Space), F. E. Marshall (NASA/GSFC),\nB. Mingo (U Leicester), K. L. Page (U Leicester) and\nD. M. Palmer (LANL) report on behalf of the Swift Team:\n\nAt 11:30:19 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 160917A (trigger=712505).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 295.671, +46.399 which is \n   RA(J2000)  =  19h 42m 41s\n   Dec(J2000) = +46d 23' 56\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows several overlapping peaks\nwith a total duration of about 25 sec.  The peak count rate\nwas ~2300 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 11:31:52.9 UT, 93.6 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nuncatalogued X-ray source located at RA, Dec 295.66805, 46.40321 which\nis equivalent to:\n   RA(J2000)  = 19h 42m 40.33s\n   Dec(J2000) = +46d 24' 11.6\"\nwith an uncertainty of 4.2 arcseconds (radius, 90% containment). This\nlocation is 16 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.  We\ncannot determine whether the source is fading at the present time. No\nspectrum from the promptly downlinked event data is yet available to\ndetermine the column density. \n\nThe initial flux in the 2.5 s image was 7.72e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 125 seconds with the White\nfilter  starting 99 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.  Results from the list of\nsources  generated on-board are not available at this time. No\ncorrection has been made  for the expected extinction corresponding to\nE(B-V) of 0.16. \n\nBurst Advocate for this burst is J. L. Racusin (judith.racusin 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": 19926,
  "createdOn": 1474112770000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 160917A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 160917A"
}