{
  "bibcode": "2017GCN.21214....1D",
  "body": "A. D'Ai (INAF-IASFPA), D. N. Burrows (PSU), A. Cholden-Brown (PSU),\nV. D'Elia (ASDC), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),\nF. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),\nB. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf\nof the Swift Team:\n\nAt 23:21:33 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 170607A (trigger=756284).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 7.343, +9.238 which is \n   RA(J2000) = 00h 29m 22s\n   Dec(J2000) = +09d 14' 16\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single FRED\nstructure with a duration of about 40 sec.  The peak count rate\nwas ~4000 counts/sec (15-350 keV), at ~1 sec after the trigger. \n\nThe XRT began observing the field at 23:22:47.1 UT, 73.4 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 7.3655, 9.2425 which is equivalent to:\n   RA(J2000)  = +00h 29m 27.72s\n   Dec(J2000) = +09d 14' 33.0\"\nwith an uncertainty of 4.8 arcseconds (radius, 90% containment). This\nlocation is 81 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 5.32e-09 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 83 seconds after the BAT trigger. There is a candidate afterglow in\nthe rapidly available 2.7'x2.7' sub-image at\n  RA(J2000)  =\t00:29:27.80 =\t7.36582\n  DEC(J2000) = +09:14:36.2  =\t9.24339\nwith a 90%-confidence error radius of about 0.61 arc sec. This position is 3.4\narc sec. from the center of the XRT error circle. The estimated magnitude is\n15.90 with a 1-sigma error of about  0.14. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.04. \n\nBurst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.inaf.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": 21214,
  "createdOn": 1496878367000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 170607A: Swift detection of a burst with a bright optical counterpart",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 170607A"
}