{
  "bibcode": "2016GCN.18938....1A",
  "body": "A. Amaral-Rogers (U Leicester), A. P. Beardmore (U Leicester),\nP.A. Evans (U Leicester), A. Y. Lien (GSFC/UMBC),\nP. T. O'Brien (U Leicester), K. L. Page (U Leicester) and\nD. M. Palmer (LANL) report on behalf of the Swift Team:\n\nAt 08:43:07 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 160127A (trigger=671828).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 225.956, +0.089 which is \n   RA(J2000) = 15h 03m 49s\n   Dec(J2000) = +00d 05' 20\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a multiple-peaked\nstructure with a duration of about 20 sec.  The peak count rate\nwas ~800 counts/sec (15-350 keV), at ~3 sec after the trigger. \n\nThe XRT began observing the field at 08:44:25.9 UT, 78.6 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source located at RA, Dec 225.98136, 0.07222 which is equivalent\nto:\n   RA(J2000)  = 15h 03m 55.53s\n   Dec(J2000) = +00d 04' 20.0\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nlocation is 109 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. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of 5.71\nx 10^20 cm^-2 (Willingale et al. 2013). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 81 seconds after the BAT trigger. There is a candidate afterglow in\nthe list of sources generated on-board at\n  RA(J2000)  =\t15:03:55.70 = 225.98209\n  DEC(J2000) = +00:04:23.0  =\t0.07305\nwith a 90%-confidence error radius of about 1.10 arc sec. This position is 3.9\narc sec. from the center of the XRT error circle. The estimated magnitude is\n18.13. No correction has been made for the expected extinction corresponding to\nE(B-V) of 0.06. \n\nBurst Advocate for this burst is A. Amaral-Rogers (aar14 AT le.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": 18938,
  "createdOn": 1453885529000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 160127A: Swift detection of a burst with an optical counterpart",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 160127A"
}