ИСТИНА

Comparison of activity levels of the Sun and more than 1000 active stars investigated in the framework of Exoplanet Search Programs. The further analysis of these data together with the X-ray observations allows us to discover a significant group of stars with weak chromospheric activity while their coronal radiation spans wide range. If early for estimate the age of stars from the level of chromospheric activity one used stars whose chromospheric and coronal activity are correlated, so such an approach, one-parametric gyrochronology, can not be applied for founded new group of stars. Because considerable number of these stars belongs to the spectral type lather than G6, change of the character of activity is rather associated with increase of the depth of the convective zone. Together with the detailed analysis of features of the solar cycle our consideration allows us to formulate arguments in favour of two-level dynamo and different role of large-scale and local magnetic fields in formation and the evolution of solar-like activity. New theoretical investigations in this direction are discussed.