Published online by Cambridge University Press: 27 September 2017
Based on X-ray (1-8 Å) flux data for 1977-1987, the integral spectra of solar flare energy were computed. The energy spectra were approximated by a power law N(E) α; E~n, with N being the number of flares with energy in excess of E. It is shown that the spectral index (β) varies systematically with the 11-year cycle phase.