Amplitudes of stochastically excited oscillations in main-sequence stars
G. Houdek 1,2,
N.J. Balmforth 3,
J. Christensen-Dalsgaard 4 and
D.O. Gough 1,5
Received 10 May 1999 / Accepted 7 September 1999
We present estimates of the amplitudes of intrinsically stable stochastically excited radial oscillations in stars near the main sequence. The amplitudes are determined by the balance between acoustical energy generation by turbulent convection (the Lighthill mechanism) and linear damping. Convection 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. Velocity and luminosity amplitudes are computed for stars with masses between and 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 model of spectral type F2; the values are approximately 15 times larger than those measured in the Sun.
Key words: convection turbulence stars: oscillations
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© European Southern Observatory (ESO) 1999
Online publication: November 3, 1999