TITLE: GCN CIRCULAR NUMBER: 16628 SUBJECT: Konus-Wind observation of GRB 140723A DATE: 14/07/24 11:27:45 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration, hard-spectrum GRB 140723A (Fermi-LAT detection: Bissaldi et al., GCN 16623; IPN triangulation: Hurley et al., GCN 16625; Fermi-BBM detection: Burns, GCN 16626) triggered Konus-Wind at T0=5790.357 s UT (01:36:30.357). The light curve shows a single FRED-like pulse with a total duration of ~45 s. The emission is seen up to 10 MeV. As observed by Konus-Wind, the burst had a fluence of 2.3(-0.5,+0.8)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0-0.064 s, of 5.8(-1.6,+1.9)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+33.024 s) is best fit in the 20 keV - 15 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -1.10(-0.20,+0.26), and the peak energy Ep = 1142(-452,+1005) keV, chi2 = 71/98 dof. Fitting this spectrum with the Band model yields the same values of alpha and Ep with an upper limit on beta of -1.9 The spectrum near the peak count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -1.03(-0.21,+0.26), and the peak energy Ep = 931(-287,+528) keV, chi2 = 97/98 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB140723_T05790/ All the quoted errors are at the 90% sigma confidence level. All the quoted values are preliminary.