{
  "bibcode": "2021GCN.29643....1S",
  "body": "D. Svinkin, S. Golenetskii, D. Frederiks, M. Ulanov,\nA. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 210308A\n(Swift-BAT detection: D'Elia et al., GCN Circ. 29619,\nPalmer et al., GCN Circ. 29633;\nFermi-GBM detection: Lesage et al., GCN Circ. 29626)\ntriggered Konus-Wind at T0=23879.936 s UT (06:37:59.936).\n\nThe burst light curve shows a multi-peaked structure\nwhich starts at ~T0-3.8 s and has a total duration of ~8.9 s.\nThe emission is seen up to ~1 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB210308_T23879/\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 5.00(-0.48,+0.53)x10^-6 erg/cm2,\nand a 64-ms peak flux, measured from T0+1.264 s,\nof 3.36(-0.85,+0.87)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 - 1 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -0.73(-0.32,+0.38)\nand Ep = 150(-19,+25) keV (chi2 = 49/55 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.7\n(chi2 = 49/54 dof).\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 29643,
  "createdOn": 1615378260000,
  "email": "svinkin@mail.ioffe.ru",
  "subject": "Konus-Wind detection of GRB 210308A",
  "submitter": "Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>",
  "eventId": "GRB 210308A"
}