Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-14T23:28:22.850Z Has data issue: false hasContentIssue false

Y Cygni?

Published online by Cambridge University Press:  07 August 2017

Alan H. Batten*
Affiliation:
Dominion Astrophysical Observatory Herzberg Institute of Astrophysics National Research Council of Canada 5071 West Saanich Road Victoria, B.C., Canada, V8X 4M6

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

It is often assumed that a binary begins to interact when one of its components makes contact with its Roche lobe, thus “switching on” a new evolutionary process. The example of Y Cygni is used to illustrate the view that the whole lifetime of a binary helps to determine whether or not its components will interact. Of particular importance is the interval between the formation of a binary and the arrival of its components on the main sequence, during which probably all binaries are interacting. Barring accidents, the properties of the components when they reach the main sequence will define the whole subsequent history of the system, including whether or not there will be subsequent phases of interaction triggered by contact with the Roche lobe. Like any other mechanical system a binary will tend towards the state of lowest energy consistent with the constraints on it. This it can do by losing mass, equalizing the component masses, or reducing its separation. We therefore expect systems to tend to small masses to mass-ratios of unity, or to coalesce into single stars. In any given system, probably all three tendencies exist, but one dominates. For example, W Ursae Majoris systems may be fusing into single stars. The rotation, chemical composition, and magnetic fields of the component stars may modify the evolution of a binary and be responsible for the variety of interacting systems that we observe. Most interacting pairs are losing mass to the interstellar medium, so a complete study of binary evolution must consider not only the dynamical, but also the chemical, effects of binary systems on the evolution of the Galaxy.

Type
Invited Papers
Copyright
Copyright © Kluwer 1992 

References

Aarseth, S.J. and Hills, G.J. 1972, Astron. Astrophys. , 21, 255 Google Scholar
Abt, H.A., Gomez, A.E. and Levy, S.G. 1990, Astrophys. J. Supp. , 74, 551 Google Scholar
Alexander, M.E. 1987, Mon. Not. Roy. Astron. Soc. , 227, 843 Google Scholar
Ambartsumian, V.A. 1937, Astr. Zhu. , 14, 207 Google Scholar
Batten, A.H. 1989, in Algols (I.A.U. Coll. 107), Space Sci. Rev. , 50, 1, 323 Google Scholar
Bodenheimer, P. 1981, in Fundamental Problems in the Theory of Stellar Evolution , eds. Sugimoto, D., Lamb, D.Q. & Schramm, D.N., (I.A.U. Symp. 93) D. Reidel, Dordrecht, p. 5 Google Scholar
Boss, A.P. 1984, Mon. Not. Roy. Astron. Soc. , 209, 543 Google Scholar
Boss, A.P. 1987, Comments on Astrophys. , 12, 169 Google Scholar
Budding, E. and Gallot, S. 1990, Astrophys. Space Sci. , 165, 197 Google Scholar
Chlebowski, T. 1989, Astrophys. J. , 342, 1091 Google Scholar
Conti, P.S. 1978, Ann. Rev. Astron. Astrophys. , 16, 371 Google Scholar
de Jager, C., Niewenhuijzen, H. and van der Hucht, K.A. 1988, Astron. Astrophys. Supp. , 72, 259 Google Scholar
Eddington, A.S. 1926, Mon. Not Roy. Astron. Soc. , 86, 320 Google Scholar
Gies, D.R. and Wiggs, M.S. 1991, Astrophys. J. , 375, 321 CrossRefGoogle Scholar
Girard, T. and Willson, L.A. 1987, Astron. Astrophys. , 183, 247 Google Scholar
Halbwachs, J.L. 1987, Astron. Astrophys. , 183, 234 Google Scholar
Heap, S.R. 1981, in The Universe at Ultraviolet Wavelengths: The First Two Years of International Ultraviolet Explorer , NASA CP 2238, ed. Chapman, R.D. (Washington, D.C.: NASA), p. 485Google Scholar
Howarth, I.D. and Prinja, R.K. 1989, Astrophys. J. Supp. , 69, 527 CrossRefGoogle Scholar
Hutchings, J.B. 1979, in Mass Loss and Evolution of O-type Stars (I.A.U. Symp. 83), eds. Conti, P.S. & de Loore, C.W.H., D. Reidel, Dordrecht, p. 3 Google Scholar
Huang, S.S. 1966, Ann. Astrophys. , 29, 331 Google Scholar
Knee, L.B.G., Scarfe, C.D., Mayor, M., Baldwin, B.W. and Meatheringham, S.J. 1986, Astron. Astrophys. , 168, 72 Google Scholar
Koch, R.H. 1991, in Trans. Int. Astron. Un. , XXIA, 479 Google Scholar
Kondo, Y., McCluskey, G.E. and Stencel, R.E. 1980, Astrophys. J. , 233, 906 Google Scholar
Kraft, R.P. 1967, Pub. Astron. Soc. Pacific , 79, 395 Google Scholar
Lada, C.S. 1985, Ann. Rev. Astron. Astrophys. , 23, 267 Google Scholar
Latham, D. W. 1991, verbal report to commission 30 at the I.A.U. XXI General Assembly Google Scholar
Lebovitz, N.R. 1989, in Highlights of Astron. 8, ed. McNally, D., Kluwer, Dordrecht, p. 129 Google Scholar
Magalashvili, N.L. and Kumsishvili, Ya. I. 1959, Bull. Abastumani Obs. , No. 24, 13 Google Scholar
Mochnacki, S.W. 1981, Astrophys. J. , 245, 650 Google Scholar
Olson, E.C. 1989, in Algols (I.A.U. Coll. 107), ed. Batten, A.H., Space Sci. Rev. , 50, 23 CrossRefGoogle Scholar
Plavec, M. 1983, Astrophys. J. , 275, 251 Google Scholar
Plavec, M. Kříž, S. and Horn, J. 1969, Bull Astr. Inst. Csi. , 20, 41 Google Scholar
Popper, D.M. 1980, Ann. Rev. Astron. Astrophys. , 18, 115 CrossRefGoogle Scholar
Pringle, J.E. 1989, Mon. Not. Roy. Astron. Soc. , 239, 361 Google Scholar
Reipurth, B., Lindgren, H., Nordström, B. & Mayor, M. 1990, Astron. Astrophys. , 235, 197 Google Scholar
Ritter, H. 1990, Astron. Astrophys. Supp. , 85, 1179 Google Scholar
Roxburgh, I.W., 1965, Nature , 208, 65 Google Scholar
Scarfe, C.D. 1986, J. Roy. Astron. Soc. Canada. 80, 257 Google Scholar
Shapley, H. 1948, in Centennial Symposia (Harvard Obs. Monographs No. 7), in Harvard Obs., p. 249 Google Scholar
Shore, S.N. and Brown, D.N. 1988, Astrophys. J. , 334, 1021 Google Scholar
Shu, F.H. and Lubow, S.H. 1981, Ann. Rev. Astron. Astrophys. , 19, 277 CrossRefGoogle Scholar
Struve, O. 1950, Stellar Evolution , Princeton Univ. Press, pp. 233–4Google Scholar
Thompson, R. 1985, in Protostars and Planets II , eds. Black, D.C. and Matthews, M.S., Univ. Arizona Press, Tucson, p. 434 Google Scholar
Trimble, V. 1990, Mon. Not. Roy. Astron. Soc. , 242, 79 CrossRefGoogle Scholar
Tutukov, A.V. and Yungelson, L.R. 1987, Comments on Astrophys. , 12, 51 Google Scholar
Vilhu, O. 1981, Astrophys. Space Sci. , 78, 401 Google Scholar
Walter, F.M. and Basri, G.S. 1982, Astrophys. J. , 260, 735 Google Scholar
Walter, F.M., Brown, A., Mathieu, R.D., Myers, P.C. and Vrba, F.J. 1988, Astron. J. , 96, 297 CrossRefGoogle Scholar
Wright, K.O. 1977, J. Roy. Astron. Soc. Canada , 71, 152 Google Scholar
Zola, S. 1990, Inf. Bull. Var. Stars. , No. 3537 Google Scholar