Astrophysics and Space Science

, Volume 41, Issue 2, pp 407–415

Possible effects of internal rotation in low-mass stars

  • John G. Mengel
  • Peter G. Gross


The influence of internal rotation on the evolution of a 0.85M star is investigated by the construction of model sequences. Rotation is treated by a simple one-dimensional approximation. The calculations assume solid-body rotation on the zero-age Main Sequence, followed by conservation of angular momentum in shells. The 4 cases considered have the initial angular velocities 0,2×10−4, 6×10−4, and 8×10−4/sec. All cases but the last are followed to helium ignition. Compared with the non-rotating case, the rotating models are older at Main-Sequence turnoff, develop fast-spinning central regions on the red-giant branch, and ignite helium at higher surface luminosities and at larger helium-core masses. The increases in the last two quantities are roughly proportional to the square of the initial angular velocity.

The 6×10−4 case is followed through the helium core flash to the zero-age horizontal branch. Under the assumption of spherical symmetry, the non-central ignition of helium leads to a sequence of flashes of decreasing amplitude occurring progressively closer to the center. The flashes are weaker than those encountered in previous studies and do not produce mixing.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Austin, S. M., Trentelman, G. F., and Kashy, E.: 1971,Astrophys. J. Letters 163, 79.Google Scholar
  2. Chandrasekhar, S.: 1961,Hydrodynamic and Hydromagnetic Stability, Clarendon Press, Oxford.Google Scholar
  3. Demarque, P. and Mengel, J. G.: 1971,Astrophys. J. 164, 317.Google Scholar
  4. Demarque, P. and Mengel, J. G.: 1973,Astron. Astrophys. 22, 121.Google Scholar
  5. Demarque, P., Mengel, J. G., and Aizenman, M. L.: 1971,Astrophys. J. 163, 37.Google Scholar
  6. Demarque, P., Mengel, J. G., and Sweigart, A. V.: 1972,Astrophys. J. Letters 173, 27.Google Scholar
  7. Demarque, P., Mengel, J. G., and Sweigart, A. V.: 1973,Astrophys. J. 183, 997.Google Scholar
  8. Fowler, W. A., Caughlan, G. R., and Zimmerman, B. A.: 1967,Ann. Rev. Astron. Astrophys. 5, 525.Google Scholar
  9. Fricke, K. J. and Kippenhahn, R.: 1972,Ann. Rev. Astron. Astrophys. 10, 45.Google Scholar
  10. Fusi-Pecci, F. and Renzini, A.: 1975,Astron. Astrophys. 39, 413.Google Scholar
  11. Goldreich, P. and Schubert, A.: 1968,Astrophys. J. 154, 1005.Google Scholar
  12. Gross, P. G.: 1973,Monthly Notices Roy. Astron. Soc. 164, 65.Google Scholar
  13. Hardorp, J.: 1974,Astron. Astrophys. 32, 133.Google Scholar
  14. Härm, R. and Schwarzschild, M.: 1966,Astrophys. J. 145, 496.Google Scholar
  15. James, R. A. and Kahn, F. D.: 1970,Astron. Astrophys. 5, 232.Google Scholar
  16. Kippenhahn, R., Meyer-Hofmeister, E., and Thomas, H.-C.: 1970,Astron. Astrophys. 5, 155.Google Scholar
  17. Reeves, H.: 1965, in L. H. Aller and D. B. McLaughlin (eds.),Stellar Structure, Univ. of Chicago Press, p. 113.Google Scholar
  18. Rood, R. T.: 1973,Astrophys. J. 184, 815.Google Scholar
  19. Sweigart, A. V. and Gross, P. G.: 1976,Astrophys. J. Suppl., in press.Google Scholar
  20. Thomas, H.-C.: 1967,Z. Astrophys. 67, 420.Google Scholar
  21. Zimmermann, R.: 1970, Ph.D. Thesis, University of California at Los Angeles.Google Scholar

Copyright information

© D. Reidel Publishing Company 1976

Authors and Affiliations

  • John G. Mengel
    • 1
  • Peter G. Gross
    • 2
  1. 1.Yale University ObservatoryNew HavenUSA
  2. 2.Warner and Swasey ObservatoryCase Western Reserve UniversityClevelandUSA

Personalised recommendations