TITLE: GCN CIRCULAR NUMBER: 10553 SUBJECT: Konus-Wind observation of GRB 100322A DATE: 10/03/30 13:00:13 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 intense GRB 100322A (Fermi/GBM trigger #290912711, van der Host et al., GCN 10539) triggered Konus-Wind at T0=03905.772s UT (01:05:05.772) The burst light curve shows a complex structure containing two main pulses with a total duration of ~50 s. Additionally, a much weaker pulse was observed around T0+75s. The first of the two main pulses has a distinctly softer spectrum than the second one. No evident spectral evolution was detected within the pulses. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB100322_T03905/ As observed by Konus-Wind the burst had a fluence of 7.3(+/-0.5)x10-5 erg/cm2, and a 256-ms peak flux measured from T0+31.744s of 6.5(+/-0.4)x10-6 erg/cm2/s (both in the 20 keV - 5 MeV energy range). The spectrum of the first, softer pulse (measured from T0 to T0+16.384 s) is well fitted in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which alpha = -0.86(+/-0.15), and Ep = 150(-10, +12) keV (chi2 = 72/74 dof). The spectrum of the second, harder part of the burst (from T0+16.384 to T0+45.568 s) is also well fitted in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which alpha = -0.99(+/-0.06), and Ep = 610(-62, +75) keV (chi2 = 77/74 dof). The spectrum at the maximum count rate (measured from T0+31.744 to T0+37.376 s) is well fitted in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which alpha = -0.92(+/-0.07), and Ep = 707(-70, +82) keV (chi2 = 72/74 dof). All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.