TITLE: GCN CIRCULAR NUMBER: 13789 SUBJECT: Konus-Wind observation of GRB 120919B DATE: 12/09/20 15:52:27 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-duration, moderately intense GRB 120919B (IPN detection and localization: Hurley et al., GCN 13788) triggered Konus-Wind at T0=04499.597s UT (01:14:59.401) The light curve shows multiple pulses in the time interval starting at ~T0-30s and ending at ~T0+100s. The emission in the main bursting episode is seen up to 8 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120919_T04499/ As observed by Konus-Wind, the burst had a fluence of 3.1(-0.5,+0.7)x10-5 erg/cm2, and a 256-ms peak flux, measured from T0+13.056 s, of 4.3(-0.9,+1.1)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+98.560 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.9 (-0.4, +0.5), the high energy photon index beta = -2.3 (-2.7, +0.3), the peak energy Ep = 250(-60, +190) keV, chi2 = 86.9/83 dof. The spectrum of the main bursting episode (measured from T0 to T0+16.640 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.0 (-0.2, +0.2), the high energy photon index beta = -2.4 (-1.0, +0.3), the peak energy Ep = 300(-70, +85) keV, chi2 = 76.3/83 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.