{
  "bibcode": "2015GCN.18611....1A",
  "body": "A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC),\nJ. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),\nK. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of\nthe Swift Team:\n\nAt 03:06:30 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 151118A (trigger=664078).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 57.158, +65.869, which is \n   RA(J2000)  =  03h 48m 38s\n   Dec(J2000) = +65d 52' 07\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a few peaks\nwith a duration of about 25 sec.  The peak count rate\nwas ~2600 counts/sec (15-350 keV), at ~6 sec after the trigger. \n\nThe XRT began observing the field at 03:07:36.2 UT, 66.2 seconds after\nthe BAT trigger. Using promptly downlinked data we find a fading,\nuncatalogued X-ray source with an enhanced position: RA, Dec 57.1719,\n65.9012 which is equivalent to:\n   RA(J2000)  = 03h 48m 41.25s\n   Dec(J2000) = +65d 54' 04.4\"\nwith an uncertainty of 2.4 arcseconds (radius, 90% containment). This\nlocation is 117 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 (4.54 x\n10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.9\n(+4.29/-3.55) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 250 seconds with the U filter starting\n281 seconds after the BAT trigger. No credible afterglow candidate has been\nfound in the initial data products. The 2.7'x2.7' sub-image covers none of the\nXRT error circle. The 8'x8' region for the list of sources generated on-board\ncovers 100% of the XRT error circle. The list of sources is typically complete\nto about 18.0 mag. No correction has been made for the expected extinction\ncorresponding to E(B-V) of 1.10. \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": 18611,
  "createdOn": 1447817079000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 151118A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 151118A"
}