{
  "bibcode": "2020GCN.28408....1L",
  "body": "S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),\nH. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),\nA. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (AGU),\nM. Stamatikos (OSU), T. N. Ukwatta (LANL)\n(i.e. the Swift-BAT team):\n  \nUsing the data set from T-239 to T+963 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 200909B (trigger #995288)\n(Melandri, et al., GCN Circ. 28406).  The BAT ground-calculated position is\nRA, Dec = 175.171, -31.199 deg which is\n    RA(J2000)  =  11h 40m 41.1s\n    Dec(J2000) = -31d 11' 54.7\"\nwith an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 35%.\n  \nThe mask-weighted light curve shows a single peak that stars at T-6 sec,\npeaks at T+1 sec, and ends at T+20 sec.  A hint of an extended emission\nis visible until T+40 sec.  T90 (15-350 keV) is 16.9 +- 2.2 sec (estimated error\nincluding systematics).\n  \nThe time-averaged spectrum from T-5.6 to T+14.2 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.60 +- 0.14.  The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T-0.44 sec in the 15-150 keV band\nis 1.3 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence\nlevel.\n  \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/995288/BA/",
  "circularId": 28408,
  "createdOn": 1599740076000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "GRB 200909B: Swift-BAT refined analysis",
  "submitter": "Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>",
  "eventId": "GRB 200909B"
}