On the dynamo cycle variations with rotational period.

The paper reports results of calculations of the magnetic cycle parameters, like the dynamo cycle period, the amplitude of the total magnetic energy, and the Poynting flux luminosity from the surface for the dynamo models of solar analogs with rotation periods of range from 1 to 30 days. The computations were done using the non-linear mean-field dynamo models. We do simulations both for the kinematic and non-kinematic dynamo models. The kinematic dynamo models, which take into account the non-linear $\alpha$-effect and the loss of the magnetic flux due to magnetic buoyancy, show a decrease of the magnetic cycle with the decrease of the stellar rotation period. The stars with the rotational period less than 10 days show the non-stationary long-term variations of the magnetic activity. The non-kinematic dynamo models take into account the magnetic field feedback on the large-scale flow and heat transport inside the convection zone. They show the non-monotonic variation of the dynamo period with the rotation rate. For the range of periods from 15 to 30 days, the stars with sub-equipartition dynamo regimes show a similarity to the kinematic dynamo models. A decrease of the rotation period from 15 to 10 days results in doubling of the dynamo frequency relative to the frequency of the kinematic dynamo waves. The models for the rotational periods less than 10 days show the non-stationary evolution with a slight increase in the primary dynamo period with the increase of the rotation rate. The non-kinematic models show that the growth of the dynamo generated magnetic flux with the increase of the rotation rate saturates for the star rotating with period two days and less. The saturation of the magnetic activity parameters is accompanied by depression of the differential rotation.