TITLE: GCN CIRCULAR NUMBER: 17422 SUBJECT: Konus-Wind observation of GRB 150202B DATE: 15/02/07 09:29:01 GMT FROM: Anastasia Tsvetkova at Ioffe Institute S. Golenetskii, R. Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 150202B (Fermi LAT detection: Axelsson and Vianello, GCN 17385; Fermi GBM detection: Pelassa, GCN 17388; IPN triangulation: Hurley et al., GCN 17398) triggered Konus-Wind at T0=86354.293 s UT (23:59:14.293). The KW light curve shows a bright main pulse lasting about 15 s, which is followed by a fainter second episode which started at ~T0+100 s and lasted up to ~T0+210 s. The emission in the main pulse is seen up to 10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150202_T86354/ As observed by Konus-Wind, the burst had a fluence of 4.56(-0.51,+0.67)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+3.600 s, of 1.07(-0.20,+0.20)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the main pulse (measured from T0 to T0+12.544 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.75(-0.11,+0.14), the high energy photon index beta = -2.39(-0.22,+0.15), the peak energy 234(-26,+27) keV (chi2 = 88/89 dof) The spectrum near the maximum count rate (measured from T0 to T0+5.888 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.69(-0.17,+0.21), the high energy photon index beta = -2.18(-0.19,+0.12), the peak energy 240(-38,+49) keV (chi2 = 79/79 dof) The time-averaged spectrum of the second episode (measured from T0+94.464 to T0+209.152 s) is best fit in the 20 keV - 5 MeV range by a power law with spectral index = -1.95(-0.19,+0.21) (chi2 = 77/78 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.