{
  "bibcode": "2013GCN.14587....1G",
  "body": "S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,\nP. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf\nof the Konus-Wind team, report:\n\nThe long-duration intense GRB 130504C\n(Fermi-LAT detection: Kocevski et al., GCN 14574;\nFermi-GBM detection: Burgess et al., GCN 14583)\ntriggered Konus-Wind at T0=84544.491s UT (23:29:04.491)\n\nThe light curve shows multiple partly overlapped peaks\nfrom ~T0-15 s to ~T0+105s.\nThe emission is seen up to 12 MeV.\n\nA possible hard precursor is seen in the 360-1400 keV\nlight curve at ~T0-50s, but its attribution to GRB 130504C\nis yet unclear.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB130504_T84544/\n\nAs observed by Konus-Wind, the burst\nhad a fluence of (2.0 � 0.1)x10-4 erg/cm2,\nand a 64-ms peak flux, measured from T0+21.440s,\nof (2.6 � 0.2)x10-5 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum (measured from T0 to T0+105.216 s)\nis best fit in the 20 keV - 15 MeV range\nby the GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -1.32 � 0.04,\nthe high energy photon index beta = -2.15 � 0.1,\nthe peak energy Ep = 452 � 49 keV,\nchi2 = 110/97 dof.\n\nThe spectrum at the maximum count rate\n(measured from T0+21.248 to T0+23.296 s)\nis best fit in the 20 keV - 15 MeV range\nby the GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -0.74 � 0.12,\nthe high energy photon index beta = -1.93 � 0.06,\nthe peak energy Ep = 251 � 38 keV,\nchi2 = 61/66 dof.\n\nAll the quoted results are preliminary.",
  "circularId": 14587,
  "createdOn": 1367838520000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 130504C",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 130504C"
}