{
  "bibcode": "2008GCN..8560....1M",
  "body": "J. Mao (INAF-OAB), W. H. Baumgartner (GSFC/UMBC),\nP. A. Evans (U Leicester), C. Guidorzi (INAF-OAB),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nR. Margutti (Univ Bicocca&OAB), C. Pagani (PSU),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nT. Sakamoto (NASA/UMBC) and L. Vetere (PSU) report on behalf of the\nSwift Team:\n\nAt 07:05:08 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 081127 (trigger=335715).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 332.093, +6.859 which is \n   RA(J2000) = 22h 08m 22s\n   Dec(J2000) = +06d 51' 33\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single-peak of 2\nseconds on a broader plateau with a total duration of about 30 sec. \nThe peak count rate was ~900 counts/sec (15-350 keV), at ~7 sec \nafter the trigger. \n\nThe XRT began observing the field at 07:07:10.8 UT, 121.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nfading, uncatalogued X-ray source with an enhanced position: RA, Dec\n332.0646, 6.8504 which is equivalent to:\n   RA(J2000)  = 22h 08m 15.49s\n   Dec(J2000) = +06d 51' 01.6\"\nwith an uncertainty of 2.4 arcseconds (radius, 90% containment). This\nlocation is 106 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 consistent with the Galactic value of\n6.86e+20 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 2.5 s image was 9.56e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 130 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.09.  The XRT position is 9.8 arcseconds from the B = 13 USNO-B1.0 star 0968-0627697. \n\nBurst Advocate for this burst is J. Mao (jirong.mao AT brera.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": 8560,
  "createdOn": 1227770704000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 081127: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 081127"
}