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Carbon in the Envelopes of White Dwarfs

Published online by Cambridge University Press:  12 April 2016

Francesca D’Antona
Francesca D’Antona*
Affiliation:
Osservatorio Astronomico di Roma, Italy and Department of Astronomy, University of Illinois at Urbana Champaign

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Current theory of stellar evolution predicts that stars of initial masses up to 4-6 M⊙ evolve into Carbon-Oxygen White Dwarfs surrounded by a Helium envelope and, possibly, by a Hydrogen envelope. It also predicts that the mass of the Helium envelope which remains on the star at the end of its double shell burning evolution is a function of the Carbon-Oxygen core mass (Paczynski 1975). It can be shown that this mass can be reduced – but only slightly – during the following evolution of the star towards the White Dwarf region, either by nuclear burning or by mass loss (D’Antona and Mazzitelli 1979). During the White Dwarf stage, Helium convection grows into White Dwarfs having Helium atmospheres. The maximum extension of Helium convective mass is a function of the mass of the star (Fontaine and Van Horn 1976; D’Antona and Mazzitelli 1975,1979). It turns out that the Helium envelope remnant mass is always at least three orders of magnitude larger than the maximum Helium convective mass, whatever the mass of the star may be. This statement is unlikely to be changed by refinements either in the theory of double shell burning or in the theory of White Dwarf envelope convection.

Type
Colloquium Session III
Information
International Astronomical Union Colloquium , Volume 53: White Dwarfs and Variable Degenerate Stars , August 1979 , pp. 188 - 191
Copyright
Copyright © The University of Rochester 1979

References

Bues, I. 1973, Astr. Ap., 28, 181.Google Scholar
Bues, I. 1978, Paper presented at the “3rd European Workshop on White Dwarfs”, Tel Aviv University, Israel.Google Scholar
Colvin, J., Van Horn, H.M., Starrfield, S., and Truran, J.W. 1977, Ap.J., 212, 791.Google Scholar
D’Antona, F., and Mazzitelli, I. 1975, Astr. Ap., 42, 165.Google Scholar
D’Antona, F., and Mazzitelli, I. 1979, Astr. Ap., 74, 161.Google Scholar
Fontaine, G., and Michaud, G. 1979, Ap.J., in press.Google Scholar
Fontaine, G., and Van Horn, H.M. 1976, Ap.J. Suppl. 31, 467.Google Scholar
Ford, H.C. 1978, Ap.J., 219, 595.CrossRefGoogle Scholar
Fusi Pecci, F., and Renzini, A. 1976, Astr. Ap., 46, 447.Google Scholar
Iben, I. Jr. 1976, Ap.J., 208, 165.Google Scholar
Iben, I. Jr. 1977, Ap.J., 217, 788.CrossRefGoogle Scholar
Iben, I. Jr., and Truran, J.W. 1978, Ap.J., 220, 980.CrossRefGoogle Scholar
Paczynski, B. 1975, Ap.J., 202, 558.Google Scholar
Paczynski, B. 1976, in “Structure and Evolution of Close Binary Systems”, (Dordrecht-Holland: D. Reidel Publ. Co.), p. 75.Google Scholar
Paczynski, B., and Sienkiewicz, R. 1977, Acta Astr., 22, 73.Google Scholar
Reimers, D. 1977, Astr. Ap., 61, 217.Google Scholar
Renzini, A. 1978, invited paper at the 4th European Regional meeting in Astronomy: Stars and Star Systems, Uppsala.Google Scholar
Ritter, H. 1976, M.N.R.A.S., 175, 279.Google Scholar
Robinson, E.L. 1976, Ann. Revs. Astr. Ap., 14, 119.Google Scholar
Schönberner, D. 1979, Astr. Ap., in press.Google Scholar
Starrfield, S., Sparks, W.M., and Truran, J.W. 1978, Ap.J., 226, 186.CrossRefGoogle Scholar
Vauclair, G., and Fontaine, G. 1979, Ap.J., 230, 563.CrossRefGoogle Scholar
Webbink, R.F. 1977, Ap.J., 211, 486.Google Scholar
Webbink, R.F. 1978, paper presented at the IAU Colloquium No. 46 “Changing Trends in Variable Star Research”, Hamilton, New Zealand.Google Scholar