Li abundances in the FGK dwarfs

The behaviour of the Li abundance was examined in correlation with Teff, [Fe/H], as well as with vsini and the level of activity in three stellar groups of the different temperature range. The stellar parameters and the Li abundances are presented for 150 slow rotating stars of the lower part of MS. The studied stars show a decline in the Li abundance with decreasing temperature Teff and a significant spread, which should be due to the difference of age of stars.

The correlations between the Li abundances, rotational velocities vsini, and the level of the chromospheric activity were discovered for the stars with 6000>Teff>5700K, and it is tighter for the stars with 5700>Teff>5200K. The target stars with Teff<5200K do not show any correlation between log A(Li) and vsini. The relationship between the chromospheric and coronal fluxes in active with detected Li as well as in less active stars gives a hint that there exist different conditions in the action of the dynamo mechanism in those stars.

We found that the Li-activity correlation is evident only in a restricted temperature range and the Li abundance spread seems to be present in a group of low chromospheric activity stars that also show a broad spread in the chromospheric vs. coronal activity.