{
  "bibcode": "2005GCN..3385....1B",
  "body": "S. Barthelmy (GSFC),  L. Barbier (GSFC), J. Cummings (GSFC/NRC),\nE. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD),\nH. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),\nA. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS),\nM. Suzuki (Saitama), J. Tueller (GSFC), T. Mitani (ISAS),\nF. Marshall (GSFC), T. Takahashi (ISAS)\non behalf of the Swift/BAT team:\n\nAt 04:00:19.23 UT Swift-BAT detected GRB 050509b (trigger=118749)\n(GCN Circ 3381, C. Hurkett et al.).  The refined BAT ground position\nis (RA,Dec) = 189.073,+28.991 {12:36:18,28:59:28} +- 2.8 arcmin [deg; J2000],\n(95% containment).  This is 59 arcsec from the XRT position (Kennea et al.,\nGNC 3383).  The burst was in the fully-coded FOV.  Using the event-by-event\ndata, the lightcurve shows a single spike with a duration of ~30msec.\nFurther, the hardness ratio S(50-100)/S(25-50) of ~1.5 puts this burst cleanly\nin the short-hard cluster on the hardness_ratio vs duration scatter-plot.\n \nUsing a simple power-law model, the photon index of the time-averaged\nspectrum is 1.5 +- 0.4.  The fluence in the 15-350 keV band is\n(2.3 +- 0.9) x 10^-8 erg/cm2.  The 1-s peak photon flux \nin the 15-350 band is (1.57 +- 0.36) ph/cm2/s.\nAll the quoted errors are at the 90% confidence level. \n\nWe note that location is consistant with the galaxy cluster NSC J123610+285901\nwhich has a redshift of z=0.22, which roughly translates to a distance \nof ~1 Gpc.  We also note that at this distance and the observed flux,\nthis is is an order of magnitude farther than the 27-Dec-04 SuperFlare\nevent from SGR1806-20 could be seen.",
  "circularId": 3385,
  "createdOn": 1115622409000,
  "email": "Scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 050509b: Swift-BAT refined analysis of the short hard burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <Scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 050509B"
}