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Abundance anomalies in red giants

  • S. R. Sreenivasan
  • W. J. F. Wilson
Session V: Mass Loss and Pulsation
Part of the Lecture Notes in Physics book series (LNP, volume 254)

Abstract

Scalo (1981) has reviewed observational information on abundances, luminosities, masses and other properties of peculiar red giants of the disk population. We have constructed theoretical models of 2, 3, 5 and 7M o stars allowing for the effect of rotation on mass loss and core size (ratio of surface rotational speed to break up speed of the order of 0.2) up to core helium exhaustion. These objects develop considerable mixing between the core and envelope, lose mass to an appreciable extent (30 to 40%) and display significant composition change in the surface layers.

We conclude that the chemical peculiarities of these red giants can be understood as a consequence of rotational mixing and mass-loss. We have treated the angular momentum transfer from the core to the envelope, as well as angular momentum (spin) loss from the surface. The extended mixing between the core and envelope, coupled with loss of mass from the outer layers, should result in more efficient meridional circulation and angular momentum transfer. Abundance anomalies can be seen as a natural consequence of these processes.

Keywords

Main Sequence Chemical Peculiarity Joule Dissipation Angular Momentum Transfer Intermediate Mass Star 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Abbott, D. 1980. in Evolution of 0 Type Stars, edited by P.S. Conti and C. de Loore, pp 237–240. (D. Reidel: Dordrecht, The Netherlands).Google Scholar
  2. Scalo, J.M. 1981 in Physical Processes in Red Giants, edited by I. Then and A. Renzini, pp 77–114 (D. Reidel: Dordrecht, The Netherlands).Google Scholar
  3. Sreenivasan, S.R. and Narasimha, D. 1985 Bull.AAS, 17 (in press) (Houston Meeting).Google Scholar
  4. Sreenivasan, S.R. and Wilson, W.J.F. 1985a Ap. J., 290, 653–659.CrossRefGoogle Scholar
  5. and Wilson, W.J.F. 1985b Ap. J., 292, 506–510.CrossRefGoogle Scholar
  6. and Wilson, W.J.F. 1985c in Mass-loss in Red Giants, edited by B. Zuckerman and M. Morris, pp 261–265. (D. Reidel: Dordrecht, The Netherlands).Google Scholar
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Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • S. R. Sreenivasan
    • 1
  • W. J. F. Wilson
    • 1
  1. 1.Department of PhysicsThe University of CalgaryCalgaryCanada

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