TITLE: GCN CIRCULAR NUMBER: 22453 SUBJECT: Konus-Wind observation of GRB 180223A DATE: 18/02/26 11:22:09 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 180223A (IPN Triangulation: Hurley et al., GCN 22451) triggered Konus-Wind at T0=22171.045 s UT (06:09:31.045) The burst light curve shows a bright, multi-peaked structure, which started at ~T0-20 s and peaked at ~T0+30 s. The total duration of the burst is ~200 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of (8.9 ± 1.0)x10^-5 erg/cm2 and a 64-ms peak energy flux, measured from T0+30.912, of (1.0 ± 0.1)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+62.464 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.00 (-0.10,+0.12), the high energy photon index beta = -2.31 (-0.32,+0.18), the peak energy Ep = 284 (-31,+33) keV, chi2 = 83/97 dof. The spectrum near the peak count rate (measured from T0+24.832 to T0+38.656 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.95 (-0.09,+0.10), the high energy photon index beta = -2.44 (-0.40,+0.21), the peak energy Ep = 310 (-37,+43) keV, chi2 = 98/97 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180223_T22171/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.