{
  "bibcode": "2020GCN.27577....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 200412A\n(BALROG localization: Kunzweiler et al., GCN Circ. 27546;\nFermi-GBM detection: Mailyan and Hamburg., GCN Circ. 27550;\nIPN triangulation: Hurley et al., GCN Circ. 27560)\ntriggered Konus-Wind at T0=25034.8 s UT (06:57:14.800).\n\nThe burst light curve shows a multipeaked structure\nwhich starts at ~T0-0.2 s and has a total duration of ~13.3 s.\nThe emission is seen up to ~4 MeV.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 3.27(-0.32,+0.35)x10^-5 erg/cm2,\nand a 64-ms peak flux, measured from T0+3.792 s,\nof 1.18(-0.15,+0.15)x10^-5 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+13.056 s)\nis best fit in the 20 keV - 4 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.59(-0.11,+0.12),\nthe high energy photon index beta = -2.68(-0.41,+0.23),\nthe peak energy Ep = 229(-19,+20) keV\n(chi2 = 56/68 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0+0.256 to T0+4.864 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 = -0.69(-0.08,+0.09)\nand Ep = 275(-16,+18) keV (chi2 = 47/68 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.8\n(chi2 = 46/67 dof).\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB200412_T25034/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 27577,
  "createdOn": 1586878715000,
  "email": "ridnaia@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 200412A",
  "submitter": "Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>",
  "eventId": "GRB 200412A"
}