{
  "bibcode": "2004GCN..2925....1P",
  "body": "D. Palmer (LANL), S. Barthelmy, L. Barbier (GSFC), S. Campana (OAB),\nJ. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC),\nD. Hullinger (GSFC/UMD), K. Hurley (UCB), H. Krimm (GSFC/USRA),\nC. Markwardt (GSFC/UMD), K. McLean (LANL), T. Sakamoto (GSFC),\nG. Sato (ISAS), M. Suzuki (Saitama), M. Tashiro (Saitama), J. Tueller (GSFC)\non behalf of the Swift-BAT team:\n\nThe Burst Alert Telescope (BAT) on Swift triggered on and recorded\nthe super-flare outburst of SGR1806-20 at 21:30:26 2004-12-27.  We did not\nlocalize the burst because it was outside the coded aperture FOV of the instrument.\nThe angle from the bore sight was 105 degrees, illuminating the instrument\nfrom slightly underneath the plane of the detectors through the XRT and UVOT\ninstruments and the body of the spacecraft.  Even with the absorption\nfrom this material, the main peak countrate in the detector array\nis saturated at 2.5E6 evts/sec (the maximum count rate the detector electronics\nis capable of).  The FWHM of the main peak was ~0.5 sec.\n\nAfter the main peak, BAT recorded a series of 51 pulsations\nwith a period of 7.56 sec and with three peaks within each pulsation.\n\nPrior to the super-flare peak, there was a precursor peak at T-143 sec,\nThe peak count rate (well below the BAT instrumental saturation level)\nwas 31,000 evts/sec (15-350 keV, with nearly all counts below 100 keV) \nand with a square profile of rise and fall times less than 100 msec and\nwidth of 1.2 sec.",
  "circularId": 2925,
  "createdOn": 1104435107000,
  "email": "palmer@nis.lanl.gov",
  "subject": "SGR1806-20: Swift-BAT observation of the 041227 super-flare",
  "submitter": "David Palmer at LANL  <palmer@nis.lanl.gov>"
}