{
  "bibcode": "2016GCN.18951....1P",
  "body": "K. L. Page (U Leicester) and S. D. Barthelmy (GSFC) report on behalf\nof the Swift Team:\n\nAt 08:20:31 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 160131A (trigger=672236).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 78.182, -7.067 which is \n   RA(J2000)  =  05h 12m 44s\n   Dec(J2000) = -07d 04' 02\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a large FRED-like peak\nstructure with a duration of about 100 sec.  The peak count rate\nwas ~8100 counts/sec (15-350 keV), at ~16 sec after the trigger. \n\nThe XRT began observing the field at 08:21:41.6 UT, 69.7 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 78.1700, -7.0489 which is equivalent to:\n   RA(J2000)  = +05h 12m 40.80s\n   Dec(J2000) = -07d 02' 56.0\"\nwith an uncertainty of 4.7 arcseconds (radius, 90% containment). This\nlocation is 77 arcseconds from the BAT onboard position, within the BAT\nerror circle. No event data are yet available to determine the column\ndensity using X-ray spectroscopy. \n\nThe initial flux in the 2.5 s image was 1.29e-08 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 78 seconds after the BAT trigger. There is a candidate afterglow in\nthe rapidly available 2.7'x2.7' sub-image at\n  RA(J2000)  =\t05:12:40.34 =  78.16810\n  DEC(J2000) = -07:02:59.1  =  -7.04975\nwith a 90%-confidence error radius of about 0.61 arc sec. This position is 7.5\narc sec. from the center of the XRT error circle. The estimated magnitude is\n13.88 with a 1-sigma error of about  0.14. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.11. \n\nBurst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). \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": 18951,
  "createdOn": 1454229146000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 160131A: Swift detection of a burst with an optical counterpart",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 160131A"
}