{
  "bibcode": "2010GCN.11411....1W",
  "body": "C. W. Wolf (PSU), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),\nS. Campana (INAF-OAB), N. Gehrels (NASA/GSFC), D. Grupe (PSU),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), W.B Landsman (GSFC),\nV. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC) and\nP. T. O'Brien (U Leicester) report on behalf of the Swift Team:\n\nAt 19:13:23 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 101117B (trigger=438675).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is RA, Dec 172.909, -72.662 which is \n   RA(J2000) = 11h 31m 38s\n   Dec(J2000) = -72d 39' 41\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a two-spike\nstructure with a duration of about 6 sec.  The peak count rate\nwas ~7000 counts/sec (15-350 keV), at ~3 sec after the trigger. \n\nThe XRT began observing the field at 19:14:40.9 UT, 77.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find a fading,\nuncatalogued X-ray source located at RA, Dec 173.00251, -72.66317 which\nis equivalent to:\n   RA(J2000)  = 11h 32m 0.60s\n   Dec(J2000) = -72d 39' 47.4\"\nwith an uncertainty of 3.7 arcseconds (radius, 90% containment). This\nlocation is 100 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 (1.33 x\n10^21 cm^-2, Kalberla et al. 2005), with an excess column of 2.2\n(+2.09/-1.81) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the white\nfilter  starting  82 seconds after the BAT trigger.  No credible\nafterglow candidate  has been found in the initial data products.  The\n2.7' x 2.7' sub-image covers 100%  of the XRT error circle.  The\nestimated 3-sigma upper limit is white > 20.4 mag.  No correction has\nbeen made for the expected Galactic extinction corresponding to a \nreddening of E_{B-V} =  0.38 mag.  Photometry is on the UVOT\nphotometry system of Poole et al. (2008). \n\nBurst Advocate for this burst is C. W. Wolf (cwolf AT astro.psu.edu). \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": 11411,
  "createdOn": 1290022061000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 101117B: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 101117B"
}