{
  "bibcode": "2017GCN.21852....1T",
  "body": "A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,\nM. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe long-duration, hard-spectrum, bright GRB 170904A\n(IPN Triangulation: Hurley et al., GCN 21820)\ntriggered Konus-Wind at T0=35162.28 s UT (09:46:02.280).\n\nThe burst light curve shows multiple emission pulses\nin the interval from ~T0-56 s ~T0+30 s.\nThe emission is seen up to ~19 MeV.\nWeak count rate increases are seen in the same S1 KW detector\nat ~T0-560 s and ~T0-350 s, however their attribution to this\nGRB is unclear.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 1.73(-0.09,+0.09)x10^-4 erg/cm2,\nand a 64-ms peak energy flux, measured from T0+11.728 s,\nof 1.90(-0.32,+0.32)x10^-5 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum of the burst\n(measured from T0 to T0+22.016 s)\nis best fit in the 20 keV - 19 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.69(-0.05,+0.06),\nthe high energy photon index beta = -2.17(-0.10,+0.08),\nthe peak energy Ep = 466(-36,+40) keV,\nchi2 = 115/97 dof.\n\nThe spectrum near the peak count rate\n(measured from T0+9.984 to T0+11.776 s)\nis best fit in the 20 keV - 19 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.73(-0.11,+0.13),\nthe high energy photon index beta = -2.19(-0.24,+0.15),\nthe peak energy Ep = 441(-72,+87) keV,\nchi2 = 53/67 dof.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB170904_T35162/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 21852,
  "createdOn": 1504883556000,
  "email": "tsvetkova@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 170904A",
  "submitter": "Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>",
  "eventId": "GRB 170904A"
}