{
  "bibcode": "2008GCN..7673....1U",
  "body": "T. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),\nJ. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),\nH. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),\nJ. Mao (INAF-OAB), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),\nG. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-239 to T+963 sec from recent telemetry downlinks,\nwe report further analysis of BAT GRB 080503 (trigger #310785)\n(Mao, et al., GCN Circ. 7665).  The BAT ground-calculated position is\nRA, Dec = 286.686, 68.803 deg, which is \n   RA(J2000)  =  19h 06m 44.7s \n   Dec(J2000) = +68d 48' 09.2\" \nwith an uncertainty of 3.5 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 75%.\n \nThe mask-weighted light curve shows an initial spike starting at ~T+0.1 sec\nwith a fast rise to a peak at ~T+0.2 sec, with a roughly exponential decay\ndown to background at ~T+0.7 sec.  The softer emission starts at about T+10 sec,\nrising with two peaks at about T+26 and +37 sec, and then falling to background\nlevels at T+220+/-20 sec.  T90 (15-350 keV) is 170 +- 40 sec (estimated error\nincluding systematics).\n \nThe time-averaged spectrum from T+0.2 to T+220.6 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n2.00 +- 0.13.  The fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T+26.58 sec in the 15-150 keV band\nis 0.9 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence level.\n\nAs to whether this burst is a SHB with extended emission or a Long burst\nwith a particularly short pulse at the beginning, we can not say yet.  Looking\nat the 4-band lightcurves, the initial spike is harder than the later emission.\nWe are waiting for (a) separate spectral analysis on the two portions\nof the lightcurve, and (b) for the lag analysis.  We are currently in an 8-hour\ngap in the downlink sessions, so it will be a while before we can say\nwith better confidence if this is truely a SHB or not.  We will issue\nanother circular.\n \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/310785/BA/",
  "circularId": 7673,
  "createdOn": 1209844968000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 080503, Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 080503"
}