We present a method of 13 late-type main-sequence stars chromospheric flux observation data calculations. These Sun-like stars have well-determined cyclic flux variations similar to the 11-year solar activity cycle. Our flux prediction is based on chromospheric HK emission time series measurements from the Mount Wilson Observatory and comparable solar data. We show that solar three - component modeling explains well the stellar observations. We find that the 10 - 20% of K - stars disc’s surfaces are occupied by bright active regions.
Lean, J.L. and Scumanich A. (1983) Three - structured model of solar chromosphere based on the NIMBUS-7 satellite observations, Journal of Geophysical Research, A88, 5751-5765. doi.org/10.1029/JA088iA07p05751
Cook, J.W., Brueckner, G.E. and Van Hoosier, M.E., (1980) The center-to limb behavior of solar active regions at ultraviolet, Journal of Geophysical Research, A85, 2257-2266. doi.org/10.1029/JA085iA05p02257