{
  "bibcode": "2019GCN.26100....1R",
  "body": "A.Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,\nM. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 191027A\n(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 26078;\nIPN triangulation: Hurley et al., GCN Circ. 26087)\ntriggered Konus-Wind at T0=55143.905 s UT (15:19:03.905).\n\nThe burst light curve shows a single pulse\nstarted at ~T0-0.1 s with a total duration of ~7.1 s.\nThe emission is seen up to ~4 MeV.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 5.24(-1.01,+1.84)x10^-6 erg/cm2,\nand a 64-ms peak flux, measured from T0-0.002 s,\nof 7.53(-2.28,+2.60)x10^-6 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-averaged spectrum of the burst\n(measured from T0 to T0+8.448 s)\nis best fit in the 20 keV - 4 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -1.28(-0.22,+0.26)\nand Ep = 443(-153,+468) keV (chi2 = 68/73 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.0\n(chi2 = 68/72 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0 to T0+0.064 s)\nis best fit in the 20 keV - 4 MeV range\nby a power law with exponential cutoff model\nwith  alpha = -0.09(-0.61,+0.84)\nand Ep = 444(-106,+210) keV (chi2 = 8/15 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.2\n(chi2 = 8/14 dof).\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB191027_T55143/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 26100,
  "createdOn": 1572465833000,
  "email": "ann_kozlova@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 191027A",
  "submitter": "Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>",
  "eventId": "GRB 191027A"
}