TITLE: GCN CIRCULAR NUMBER: 11971 SUBJECT: Konus-Wind observation of GRB 110422A DATE: 11/04/24 09:30:07 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long bright GRB 110422A (Swift-BAT trigger #451901: Mangano et al., GCN 11957; Palmer et al., GCN 11959) triggered Konus-Wind at T0(KW)=56502.948 s UT (15:41:42.948). The burst light curve shows a multipeaked structure with a duration of ~40 s. As observed by Konus-Wind the burst had a fluence of (8.56 +/- 0.02)x10^-5 erg/cm2, and a 64-ms peak flux measured from T0+18.128 s of (1.20 +/- 0.15)x10^-5 erg/cm2/s (both in the 20 keV - 2 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+38.656 s) can be fitted (in the 20 keV - 2 MeV range) by the GRB (Band) model for which: the low-energy photon index is alpha = -0.65 +/- 0.06, the high energy photon index beta = -2.96(-0.19, +0.14), the peak energy Ep = 152 +/- 5 keV (chi2 = 96.8/64 dof). The spectrum at the maximum count rate (measured from T0+17.664 to T0+18.432 s) is well fitted (in the 20 keV - 2 MeV range) by the GRB (Band) model, for which: the low-energy photon index alpha = -0.53 (-0.14, +0.17), the high energy photon index beta = -2.65 (-0.62, +0.28), the peak energy Ep = 246(-34, +37) keV (chi2 = 55.7/48 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB110422_T56502/