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Mechanisms of Separation of Elements

Published online by Cambridge University Press:  12 April 2016

Georges Michaud  and
C. R. Proffitt
Georges Michaud
Affiliation:
CERCA, and Département de Physique, Université de Montréal, C. P. 6128, Succursale A, Montréal, H3C 3J7, QUE, CANADA.
C. R. Proffitt
Affiliation:
Space Telescope Science Institute

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Since the last IAU Colloquium devoted to Ap stars, die continuous development of high signal to noise observations and of computerized analysis tools have greatly increased the effectiveness of abundance anomalies as a probe of hydrodynamical processes in stars. Until the 1980s, they seemed limited to ApBp and AmFm stars where the effects are largest. More recently the abundances of Li and He have been suggested to play important diagnostic roles for hydrodynamics in both the Sun (Proffitt and Michaud 1991b, Pinsonneault et al. 1989) and Halo stars (Proffitt and Michaud 1991a, Pinsonneault et al. 1992, Vauclair 1988, Charbonnel et al. 1992, Deliyannis and Demarque 1991). The observation of a Li abundance gap in F stars of clusters has raised the question of the link between these objects and the AmFm stars (Michaud 1986, Charbonneau and Michaud 1988, 1991) or alternately with solar type stars. The observed Li abundance on die subgiant branch sheds some light on this problem (Charbonneau et al. 1989; Charbonnel and Vauclair 1992). In solar type stars, the observed Li abundance constrains the superficial turbulence that may inhibit surface He gravitational settling (Proffitt and Michaud 1991b) whose effects can be detected using solar seismology (Guzik and Cox 1992, Dziembowski et al. 1992).

Type
V. Theory of CP Star Photospheres
Information
International Astronomical Union Colloquium , Volume 138: Peculiar versus Normal Phenomena in A-Type and Related Stars , 1993 , pp. 439 - 449
Copyright
Copyright © Astronomical Society of the Pacific 1993

References

Alecian, G., Michaud, G., and Tully, J. 1992, preprint.Google Scholar
Atukov, S.N. 1986, Phys. Lett. A, 119, 121.Google Scholar
Atukov, S.N.. and Shalagin, A.M. 1988, Sov. Astron. Lett. 14, 284.Google Scholar
Babel, J., and Michaud, G. 1991, A&A, 248, 155.Google Scholar
Bancali, J.N., and Loeb, A. 1990, ApJ, 360, 267.Google Scholar
Burgers, J.M. 1969, Flow Equations for Composite Gases, (New York: Academic Pressi Google Scholar
Chaboyer, B. and Zahn, J.-P. 1992, A&A, 253, 173.Google Scholar
Chapman, S., and Cowling, T.G. 1970, The Mathematical Theory of non-uniform Gases (3d ed.; Cambridge: Cambridge University Press).Google Scholar
Charbonneau, P., 1992, A&A, submitted.Google Scholar
Charbonneau, P., 1992, in Cool Stars, Stellar Systems, and the Sun: Seventh Cambridge Workshop, eds. Giampapa, M.S. and Bookbinder, J.A., (San Francisco: Astronomical Society of the Pacific), p. 416. Google Scholar
Charbonneau, P., and Michaud, G. 1988, ApJ, 334, 746.Google Scholar
Charbonneau, P., and Michaud, G. 1991, ApJ, 370, 693.Google Scholar
Charbonneau, P., Michaud, G., and Proffitt, C.R. 1989, ApJ, 347, 821.CrossRefGoogle Scholar
Charbonnel, C., and Vauclair, S. 1992, A&A, submitted.Google Scholar
Charbonnel, C., Vauclair, S., and Zahn, J.-P. 1992, A&A, 255, 191.Google Scholar
Cox, A.N., Morgan, S.M., Rogers, F.J., and Iglesias, C.A. 1992, ApJ, 393, 272.Google Scholar
Deliyannis, C.P., and Demarque, P. 1991, ApJ, 379, 216.Google Scholar
Deliyannis, C.P., Pinsonneault, H.H., and Duncan, D.K. 1992, ApJ, in press.Google Scholar
Dziembowski, W.A., Pamyatnykh, A.A., and Sienkeiwicz, R. 1992, preprint.Google Scholar
Garcia Lopez, R.J. and Spruit, H.C. 1991, ApJ, 377, 268.Google Scholar
Guzik, J.A., and Cox, A.N. 1992, ApJL., 386, 729.Google Scholar
Kosovichev, A.G., Christensen-Dalsgaard, J., Dappen, W., Dziembowski, W.A., Gough, D.O., and Thompson, M.J. 1992, M.N., in press.Google Scholar
Kurucz, R.L. 1991, in Stellar Atmospheres: Beyond Classical Models, ed. by Crivellari, L., Hubeny, I. and Hummer, D.G., NATO ASI Series (Dordrecht, Kluwer), p. 440. Google Scholar
LeBlanc, F., and Michaud, G. 1992, ApJ, submitted.Google Scholar
Martel, A. 1979, Internal Report, Université de Montréal.Google Scholar
Michaud, G. 1976, in Physics of Ap Stars. IAU Colloquium No. 32. ed. Weiss, W W., Jenkner, H., and Wood, H.J. (Universitatsternwarte Wien, Vienna), p.351. Google Scholar
Michaud, G. 1980, AJ, 85, 589.Google Scholar
Michaud, G. 1986, in Upper Main Sequence Stars with Anomalous Abundances, IAU Colloquium 90, Ed. Cowley, C.R., Dworetsky, M.M. and Mégessier, C. (Doldrecht: Reidel), p. 459. Google Scholar
Michaud, G. 1991a, in IAU Symposium 145, Evolution of Stars: the Photospheric Abundance Connection, Golden Sands, Bulgaria, 25-31 August, ed. Michaud, G. and Tutukov, A. (Kluwer), pp. 111–124.Google Scholar
Michaud, G. 1991b, Annales de Physique Fr., 16, 481.Google Scholar
Michaud, G., Montmerle, T., Cox, A.N., Magee, N.H., Hodson, S.W., and Martel, A. 1979, ApJ, 234, 206.Google Scholar
Michaud, G., and Proffitt, C.R. 1992, in Inside the Stars, IAU COLLOQUIUM 137, Vienna, April 1992, ed. Baglin, A. and Weiss, W.W., (Conference Series of the PASP), in press.Google Scholar
Michaud, G., and Richer, J. 1992, in Origin and Evolution of the Elements, Paris, June 1992, ed., Prantzos, N. and Cassé, M., (Cambridge University Press), in press.Google Scholar
Paquette, C., Pelletier, C., Fontaine, G., and Michaud, G. 1986, ApJS, 61, 177.Google Scholar
Pinsonneault, M.H., Deliyannis, C.P., and Demarque, P. 1992, ApJS, 78, 179.Google Scholar
Pinsonneault, M.H., Kawaler, S.D., and Demarque, P. 1990, ApJS, 74, 501.Google Scholar
Pinsonneault, M.H., Kawaler, S.D., Sofia, S., and Demarque, P. 1989, ApJ, 338, 424.Google Scholar
Proffitt, C.R., and Michaud, G. 1991a, ApJ, 371, 584.Google Scholar
Proffitt, C.R., and Michaud, G. 1991b, ApJ, 380, 238.Google Scholar
Richer, J. 1992, Thèse de doctorat, Université de Montréal.Google Scholar
Richer, J., and Michaud, G. 1992, in preparation.Google Scholar
Rogers, F.J., and Iglesias, C.A. 1992, ApJS, 79, 507.Google Scholar
Soderblom, D.R., Jones, B.F., Balachandran, S., Stauffer, J.R., Duncan, D.K., Fedele, S., and Hudon, J.D. 1992, AJ, submitted.Google Scholar
Schatzman, E., 1962, Ann. Astrophys 25, 18.Google Scholar
Schatzman, E., 1977, A&A, 56, 211.Google Scholar
Spiegel, E.A. and Zahn, J.-P., 1970, Comments Astrophys. Space Phys. 2, 178.Google Scholar
Spite, F., and Spite, M. 1982, A&A, 115, 357.Google Scholar
Vauclair, S. 1988, ApJ, 335, 971.Google Scholar
Vauclair, S., Michaud, G., and Charland, Y. 1974, A&A, 31, 381.Google Scholar
Weber, E.J. and Davis, L. Jr. 1967, ApJ, 148, 217.Google Scholar
Zahn, J.-P. 1992, A&A, in press.Google Scholar
Zahn, J.-P. 1974, in Stellar Instability and Evolution, ed. Ledoux, P., Noels, A., and Rodgers, A.W. (Dordrecht: Reidel), p. 185. Google Scholar