TITLE: GCN CIRCULAR NUMBER: 12996 SUBJECT: Konus-Wind observation of GRB 120226A DATE: 12/02/29 09:07:45 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 120226A (GBM trigger 351982459; IPN localization: Hurley at al., GCN 12993; Fermi/LAT & Fermi/GBM detection: Omodei et al., GCN 12995) triggered Konus-Wind at T0=75259.724s UT (20:54:19.724) The light curve shows multiple partly overlapped pulses. A total duration of the burst is ~80 s. The emission is seen up to ~4 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120226_T75259/ As observed by Konus-Wind the burst had a fluence of 7.5(-1.2,+0.9)x10-5 erg/cm2, and a 256-ms peak flux, measured from T0+25.600 s, of 2.5(-0.3,+0.3)x10-6 erg/cm2/s (both in the 20 keV - 5 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+78.086 s) is best fit in the 20 keV - 5 MeV range with the GRB (Band) model, for which: the low-energy photon index alpha = -1.01 (-0.07, +0.07), the high energy photon index beta = -2.5 (-0.9, +0.2), the peak energy Ep = 279(-28, +39) keV, chi2 = 88.6/75 dof. The spectrum at the maximum count rate (measured from T0+20.992 to T0+28.928 s) is best fit in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which alpha = -0.96 (-0.09, +0.10), and Ep = 317(-42, +54) keV, chi2 = 79.0/76 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.