The Main Factors Determining the Character of the Solar-Type Activity1

摘要

For further study of evolution of solar-type activity, we analyzed indices of activity together with results of spectral observations of Li abundances in atmospheres of F, G, K dwarfs. We confirm the Li depletion accordingly to the mixing theory which is sensitive to the depth of the convection zone. We found that the Li-activity correlation exists only in restricted intervals of T_eff and it is tighter for the stars with 5700 > T_eff > 5200 K. This correlation between log A(Li) and the chromospheric activity index log R'_HK can mean that the depth of the lower boundary of the convection zone is a significant factor not only for the Li abundance, but also for development of definite features of activity. Particularly, these features appear in change of interrelation between indices of the chromospheric and coronal activity for G stars the hotter and colder than the Sun that presumably associated with different role of large-scale and local magnetic fields in formation of activity. Thus, our conclusions indicate that the main factors of formation of activity are the axial rotation rate and the thickness of the convection zone.