TITLE: GCN CIRCULAR NUMBER: 10939 SUBJECT: Konus-Wind observation of GRB 100701B DATE: 10/07/06 08:05:36 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 bright hard GRB 100701B (localized by IPN, Golenetskii et al., GCN 10938) triggered Konus-Wind at T0=42319.075s UT (11:45:19.075) The burst light curve consists of several (>6) short hard pulses with a total duration of ~15 s. The emission is clearly seen up to 10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB100701_T42319/ As observed by Konus-Wind the burst had a fluence of 5.0(+/-0.85)x10-5 erg/cm2, and a 256-ms peak flux measured from T0+3.584s of 2.2+/-0.3)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.640 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model, for which: the low-energy photon index alpha = -0.90 (+/-0.10), the high energy photon index beta = -2.7 ( <-2.1 ), the peak energy Ep = 1186(-243, +294)keV (chi2 = 74.4/84 dof). The spectrum at the maximum count rate (measured from T0+0.256 to T0+8.848 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model, for which: the low-energy photon index alpha = -0.80 (+/-0.10), the high energy photon index beta = -2.6 ( <-2.2 ), the peak energy Ep = 1202(-217, +246)keV (chi2 = 90/84 dof). All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.