{
  "bibcode": "2016GCN.20210....1K",
  "body": "D. Kocevski (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC),\nJ. R. Cummings (NASA/UMBC), B. Mingo (U Leicester),\nK. L. Page (U Leicester), B. Sbarufatti (INAF-OAB/PSU) and\nM. H. Siegel (PSU) report on behalf of the Swift Team:\n\nAt 07:11:39 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 161129A (trigger=724438).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 316.193, +32.125 which is \n   RA(J2000)  =  21h 04m 46s\n   Dec(J2000) = +32d 07' 30\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows multiple peaks\nwith a duration of about 50 sec.  The peak count rate\nwas ~4400 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 07:13:01.8 UT, 82.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source located at RA, Dec 316.22890, 32.13574 which is equivalent\nto:\n   RA(J2000)  = 21h 04m 54.94s\n   Dec(J2000) = +32d 08' 08.7\"\nwith an uncertainty of 3.6 arcseconds (radius, 90% containment). This\nlocation is 116 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. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (2.50 x\n10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.5\n(+2.84/-2.37) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White \nfilter  starting 86 seconds after the BAT trigger. No credible \nafterglow candidate has  been found in the initial data products. The \n2.7'x2.7' sub-image does not cover the XRT error circle. The 8'x8'\nregion for the list of sources generated on-board covers 100% of the \nXRT error circle. The list of sources is typically complete to about\n18 mag.  No correction has been made  for the expected extinction \ncorresponding to E(B-V) of 0.21. \n\nBurst Advocate for this burst is D. Kocevski (dankocevski AT gmail.com). \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": 20210,
  "createdOn": 1480404745000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 161129A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 161129A"
}