Konus-Wind observation of GRB 170529A

The long-duration GRB 170529A (IPN triangulation: Hurley et al., GCN 21165) triggered Konus-Wind at T0=25541.567 s UT (07:05:41.567). The burst light curve shows two separate multipeaked episodes: the first from ~T0-6 s to ~T0+52 s and the second weaker/softer from ~T0+176 s to ~T0+220 s. The total duration of the burst is ~226 s. The emission is seen up to 20 MeV. As observed by Konus-Wind, the burst had a fluence of 1.73(-0.40,+0.62)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+7.504 s, of 1.54(-0.27,+0.28)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+222.464 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.96(-0.16,+0.46), the high energy photon index beta = -2.23(-1.36,+0.41), the peak energy Ep = 422(-188,+142) keV (chi2 = 89/98 dof). The spectrum near the maximum count rate (measured from T0+6.656 to T0+11.008 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.49(-0.10,+0.11), the high energy photon index beta = -2.41(-0.28,+0.18), the peak energy Ep = 486(-54,+59) keV (chi2 = 75/87 dof). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170529_T25541/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.