On chromospheric variations modeling for main-sequence stars of G and K spectral classes

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