Atmospheric Dynamics of Luminous Stars
A review is given of data and theories on the motion fields in super and hypergiants with special reference to LBV’s. We show that the radiative momentum flux is incapable of driving the episodical bursts of mass loss of these stars, and that there are several indications that the LBV-phenomenon is hydrodynamically driven. The sum of turbulent and radiative accelerations in the atmospheres of the most luminous stars compensates the gravitational acceleration for stars near the Humphreys-Davidson limit. This explains their atmospheric near-instability. The motion field in the atmosphere of a typical LBV consists mainly of low-order gravity waves, while acoustic waves are rapidly damped. These gravitation waves may be stochastic rather than coherently ordered. These stochastic pulsations are assumed to be responsible for the LBV phenomenon.
KeywordsMomentum Flux Stellar Wind Motion Field Turbulent Pressure Radiative Acceleration
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- Carpay, J., De Jager, C. and Nieuwenhuijzen, H.: 1989, Astron. Astrophys. submittedGoogle Scholar
- De Jager, C.: 1980, The Brightest stars, Reidel, DordrechtGoogle Scholar
- De Koter, A.: 1989, Astron. Astrophys. in prepGoogle Scholar
- Nieuwenhuijzen, H. and De Jager, C.: 1989, These ProceedingsGoogle Scholar
- Schellekens, E., De Jager, C. and Nieuwenhuijzen, H.: 1989, Astron. Astrophys in prepGoogle Scholar