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The importance of helium and metals diffusion in stars

Published online by Cambridge University Press:  25 May 2016

Charles R. Proffitt
Charles R. Proffitt*
Affiliation:
Computer Sciences Corporation and Catholic University of America, Code 680, Goddard Space Flight Center, Greenbelt MD 20771, USA

Abstract

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Comparisons between models of the solar interior and sound speed profiles derived from inversions of helioseismic data have demonstrated that it is essential to include the effects of gravitational settling when calculating the structure and evolution of the Sun. Including settling should also be necessary for models of metal poor main-sequence stars and results in a substantial reduction in the ages derived for globular clusters.

In many cases it is clear that competing hydrodynamic processes, such as mass loss or rotationally driven mixing, will limit the effectiveness of gravitational separation of chemical elements. However, the quantitative details and even the relative importance of the different processes in various types of stars remains poorly understood.

Type
Stellar Interiors
Information
Symposium - International Astronomical Union , Volume 189: Fundamental Stellar Properties: The Interaction Between Observation and Theory , 1997 , pp. 355 - 360
Copyright
Copyright © Kluwer 1997 

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