Amplitudes of stochastically excited oscillations in main-sequence stars

We present estimates of the amplitudes of intrinsi- cally stable stochastically excited radial oscillations in stars near the main sequence. The amplitudes are determined by the bal- ance between acoustical energy generation by turbulent con- vection (the Lighthill mechanism) and linear damping. Convec- tion is treated with a time-dependent, nonlocal, mixing-length model, which includes both convective heat flux and turbulent pressure in both the equilibrium model and the pulsations. Ve- locity and luminosity amplitudes are computed for stars with masses between0:9 M and 2:0 M in the vicinity of the main sequence, for various metallicities and convection parameters. As in previous studies, the amplitudes are found to increase with stellar mass, and therefore with luminosity. Amongst those stars that are pulsationally stable, the largest amplitudes are predicted for a 1:6 M model of spectral type F2; the values are approx- imately 15 times larger than those measured in the Sun.