{
  "bibcode": "2020GCN.27010....1S",
  "body": "M. Stamatikos (OSU), S. D. Barthelmy (GSFC),\nJ. R. Cummings (CPI), P. A. Evans (U. Leicester),\nH. A. Krimm (NSF), S. Laha (GSFC/UMBC),\nA. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),\nD. M. Palmer (LANL), T. Sakamoto (AGU),\nT. N. Ukwatta (LANL) (i.e. the Swift-BAT team):\n\nUsing the data set from T-239 to T+255 sec from the recent telemetry downlink,\nwe report further analysis of BAT source Swift J0840.7-3516 (trigger #954304)\n(Evans et al., GCN Circ. 26982).  The BAT ground-calculated position is\nRA, Dec = 130.168, -35.275 deg which is\n   RA(J2000)  =  08h 40m 40.4s\n   Dec(J2000) = -35d 16' 30.9\"\nwith an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 94%.\n\nThe mask weighted light curve shows some weak emission which started before the source\n came into BAT field of view (which is ~ T-100 sec).\nKennea et al. 2020 (Atel #13452) discuss the properties of this newly discovered X-ray transient.\nThe lower limit of the duration of the burst as detected by BAT is ~ 200 sec.\nThe source went out of BAT field of view at ~T+260 sec, with a possibility of continuing emission\nwhich may be detected by other telecopes.\n\n\nThe time-averaged spectrum from -81.88 to 132.86 sec is best fit by a power law\nwith an exponential cutoff.  This fit gives a photon index 0.84 +- 0.91,\nand Epeak of 31.5 +- 8.4 keV (chi squared 67.17 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is (1.3 +- 0.1) x 10^-06 erg/cm2\nand the 1-sec peak flux measured from T-81.90 sec in the 15-150 keV band is\n0.3 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 2.26 +- 0.17 (chi squared 77.17 for 57 d.o.f.).  All the quoted errors\nare at the 90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/954304/BA/",
  "circularId": 27010,
  "createdOn": 1581090483000,
  "email": "sibasish.laha@nasa.gov",
  "subject": "Swift J0840.7-3516 (AKA GRB 200205A): Swift-BAT refined analysis",
  "submitter": "Sibasish Laha at GSFC  <sibasish.laha@nasa.gov>",
  "eventId": "GRB 200205A"
}