{
  "bibcode": "2022GCN.32688....1K",
  "body": "H. A. Krimm (NSF), S. D. Barthelmy (GSFC),\nS. Dichiara (PSU), S. Laha (GSFC/UMBC),\nA. Y. Lien (U Tampa), C. B. Markwardt (GSFC),\nD. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),\nT. Sakamoto (AGU), M. Stamatikos (OSU)\n(i.e. the Swift-BAT team):\n\nUsing the data set from T-239 to T+1371 sec from the recent\ntelemetry downlink, we report further analysis of BAT GRB 221009A\n(trigger #1126853 and #1126854) (Dichiara et al., GCN Circ. 32632).\nThe BAT ground-calculated position is\nRA, Dec = 288.254, 19.809 deg which is\n   RA(J2000)  =  19h 13m 00.9s\n   Dec(J2000) = +19d 48' 34.1\"\nwith an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 9%.\n\nThe mask-weighted light curve shows a flat and long-lasting emission\nthat may have started before the burst came into the BAT FOV at T-26 s.\nThe burst emission seems to end at ~T+1320 s, however, we cannot rule\nout the possibility that the emission extends beyond the available\nevent data that end at T+1371 s. The lower limit of T90 (15-350 keV)\nis 1068.40 +- 13.34 sec (estimated error including systematics).\n\nThe time-averaged spectrum from T+103.3 s to T+1338.7 s sec is best fit\nby a simple power-law model.  The power law index of the time-averaged\nspectrum is 2.08 +- 0.03.  The fluence in the 15-150 keV band\nis 7.4 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured\nfrom T+776.47 sec in the 15-150 keV band is 1.9 +- 0.3 ph/cm2/sec.\nAll the quoted errors are at the 90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/1126853/BA/",
  "circularId": 32688,
  "createdOn": 1665497577000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "GRB 221009A"
}