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W UMa Binaries

Published online by Cambridge University Press:  07 August 2017

O. Vilhu*
Affiliation:
Observatory and Astrophysics Laboratory, University of Helsinki, SF-00130 Helsinki, Finland

Abstract

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The origin and evolution of contact (W UMa) binaries are discussed with the help of the braking law of eq.(1). Best observationally justified parameter-values in (1) for W UMa, CV and LMXB binaries are: α ≈ 1.5, γ = 2 and f computed from eq.(2). A semi-empirical relation (eq.(5)) between the scaled magnetic torque and the fractional X-ray luminosity is proposed. First attempts of simultaneous photometric and spectroscopic surface imaging of contact binaries are described.

Type
Invited Papers
Copyright
Copyright © Kluwer 1992 

References

Barden, S.: 1985, Astrophys. J. 295, 162.Google Scholar
Barstow, M.A., Bromage, G.E. and Holberg, J.B.: 1990, in Evolution in Astrophysics , ESA SP-310, p. 375.Google Scholar
Bell, S.A., Rainger, P.P., Hilditch, R.W.: 1990, Mon. Not. R. astr. Soc. 247, 632.Google Scholar
Bopp, B.W. and Rucinski, S.M.: 1981, in Sugimoto, D., Lamb, D.Q., Schramm, D.N. (eds.) Late Stages of Stellar Evolution , D. Reidel Publ. Co., p.181.Google Scholar
Budding, E., Slee, O.B., Stewart, R.T., Beasley, A.J., Ball, L.: 1991, these proceedings.Google Scholar
Bradstreet, D.H. and Guinan, E.F.: 1990, in Ibanoglu, C. (ed.) Active Close Binaries , Kluwer Academic Publishers, p. 467.Google Scholar
Caillault, J.-P. and Helfand, : 1985, Astrophys. J. 289, 279.Google Scholar
Catalano, S., Marilli, E., Trigilio, C.: 1988, in Dupree, A.K. and Lago, M.T.V.T. (eds.) Formation and Evolution of Low Mass Stars , Kluwer Academic Publishers, p. 377.Google Scholar
Collier Cameron, A.: 1991, in Surface lnhomogeneities on Late Type Stars , Lecture Notes in Physics, Springer Verlag (in press).Google Scholar
Cruddace, R.G. and Dupree, A.K.; 1984, Astrophys. J. 277, 263.CrossRefGoogle Scholar
Eggen, O.J. and Iben, I.: 1990, Astron. J. 97, 431.Google Scholar
Fleming, T.A., Gioia, I.M., Maccacaro, T.: 1989, Astron. J. 98, 692.CrossRefGoogle Scholar
Guinan, E.F. and Bradstreet, D.H.: 1988, in Dupree, A.K. and Lago, M.T.V.T. (eds.) Formation and Evolution of Low Mass Stars , Kluwer Academic Publishers, p.345.Google Scholar
Herczeg, G.: 1991, these proceedings.Google Scholar
Hilditch, R.W., King, D.J. and McFarlane, T.M.: 1988, Mon. Not. R. astr. Soc. 231, 341.Google Scholar
Huang, S.-S.: 1966, Astrophys. J. 29, 331.Google Scholar
Kim, C.-H.: 1991, these proceedings.Google Scholar
Kurucz, R.: 1979, Astrophys. J. Suppl. 40, 1.Google Scholar
Linnell, A.P. and Olson, E.C.: 1989, Astrophys. J. 343, 909.CrossRefGoogle Scholar
Linsky, J.L.: 1988, in Cordova, F.A. (ed.) Multiwavelength Astrophysics , Cambridge Univ. Press, p.49.Google Scholar
Maceroni, C., Van't Veer, F. and Vilhu, O.: 1991, in preparation.Google Scholar
Mateo, M., Harris, H.C., Nemec, J., Olszewski, E.W.: 1990, Astron. J. 100, 469.Google Scholar
Mestel, L.: 1968, Mon. Not. R. astr. Soc. 138, 359.Google Scholar
Mestel, L. and Spruit, H.C.: 1987, Mon. Not. R. astr. Soc 226, 57.Google Scholar
Moss, D.: 1986, Mon. Not. R. astr. Soc. 218, 247.Google Scholar
Pallavicini, R., Golub, L., Rosner, R., Vaiana, G.S., Ayres, T. and Linsky, J.L.: 1981, Astrophys. J. 248, 279.Google Scholar
Piscounov, N.E., Tuominen, I. and Vilhu, O.: 1990, Astron. Astrophys. 230, 363.Google Scholar
Rahunen, T.: 1981, Astron. Astrophys. 102, 81.Google Scholar
Rahunen, T. and Vilhu, O.: 1982, in Kopal, Z. and Rahe, J. (eds.) Binary and Multiple Stars as Tracers of Stellar Evolution , D. Reidel Publ. Co., p. 289.Google Scholar
Rappaport, S., Verbunt, F. and Joss, P.C.: 1983 Astrophys. J. 275, 713.Google Scholar
Rodono, M.: 1991, these proceedings.Google Scholar
Rucinski, S.M.: 1985a, in Eggleton, P.P. and Pringle, J.E. (eds.) Interacting Binary Stars , D. Reidel Publ. Co., p.85.Google Scholar
Rucinski, S.M.: 1985b, in Eggleton, P.P. and Pringle, J.E. (eds.) Interacting Binary Stars , D. Reidel Publ. Co., p. 113.Google Scholar
Rucinski, S.M.: 1989, Comments Astrophys. 14, 79.Google Scholar
Rucinski, S.M. and Vilhu, O.: 1983, Mon. Not. R. astr. Soc 202, 1221.Google Scholar
Schatzman, E.: 1962, Ann. Astrophys. 25, 18.Google Scholar
Skumanich, A.: 1972, Astrophys. J. 171, 565.Google Scholar
Verbunt, F. and Zwaan, C.: 1981, Astron. Astrophys. Lett. 100, L7.Google Scholar
Van't Veer, F.: 1975, Astron. Astrophys. 40, 167.Google Scholar
Van't Veer, F.: 1979, Astron. Astrophys. 80, 287.Google Scholar
Van't Veer, F. and Maceroni, C.: 1989, Astron. Astrophys., 220, 128.Google Scholar
Vilhu, O.: 1982, Astron. Astrophys. 109, 17.Google Scholar
Vilhu, O. and Heise, J.: 1986, Astrophys. J. 311, 937.Google Scholar
Vilhu, O. and Moss, D.: 1986, Astron. J. 92, 1178.Google Scholar
Vilhu, O.: 1987, in Linsky, J.L. and Stencel, R.E. (eds.) Cool Stars, Stellar Systems and the Sun , Springer Verlag, p. 110.Google Scholar
Vilhu, O. and Walter, F.M.: 1987, Astrophys. J. 321, 958.Google Scholar
Vilhu, O., Neff, J.E. and Rahunen, T.: 1989, Astron. Astrophys. 208, 201.Google Scholar
Webbink, R.F.: 1976, Astrophys. J. 209, 829.Google Scholar
Vogt, S.S. and Penrod, G.D.: 1983, Publ. Astron. Soc. Pac. 95, 565.CrossRefGoogle Scholar
Vogt, S.S., Penrod, G.D. and Hatzes, A.P.: 1987, Astrophys. J. 321, 496.Google Scholar
Yamasaki, A.: 1975, Aph. Sp. Sci 34, 413.Google Scholar