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Nonradial Pulsation among δ Scuti Stars

Published online by Cambridge University Press:  15 February 2018

Michel Breger
Michel Breger*
Affiliation:
Institute of Astronomy, University of Vienna, Austria

Abstract

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The review examines recent observational and theoretical results on the nonradial pulsation of δ Scuti stars. The dominant pulsation modes are rotationally split p modes with = 1 and 2, and radial orders 1 to 4. Line-profile analyses also reveal the existence of additional high-degree modes. Nonradial pulsation is usually accompanied by slow amplitude and period variability. The small-amplitude single-mode variables are shown to be typical nonradial pulsators.

The interesting cases of 1 Mon and θ2 Tau are examined in more detail. The present status of asteroseismolgy of the δ Scuti stars is reviewed.

The periods of the four evolved δ Scuti variables studied are found to be decreasing, although stellar evolution predicts period increases due to larger radii. New work on the multiple periods of AI Vel shows that, apart from stellar evolution, an additional mechanism must exist to cause temporary period changes. It is argued that for a larger sample of stars the average period change must nevertheless reflect evolutionary changes.

Type
Stellar Seismology
Information
International Astronomical Union Colloquium , Volume 139: New Perspectives on Stellar Pulsation and Pulsating Variable Stars , 1993 , pp. 135 - 143
Copyright
Copyright © Cambridge University Press 1993

References

Balona, L. A. and Stobie, R. S. 1979, MNRAS, 189, 649 CrossRefGoogle Scholar
Balona, L. A. and Stobie, R. S. 1980, MNRAS, 190, 931 Google Scholar
Breger, M. 1989, Comm. Asteroseismology, 7, 1, Vienna: Austrian Acad. Sciences Google Scholar
Breger, M. 1990a, A&A, 240, 308 Google Scholar
Breger, M. 1990b, ASP Conf. Ser., 11, 263 Google Scholar
Breger, M., Garrido, R., Huang, L., Jiang, S.-Y., Guo, Z.-h., Frueh, M., Paparo, M. 1989, A&A, 214, 209 Google Scholar
Breger, M., Huang, L., Jiang, S.-y., Guo, Z.-h., Antonello, E., Mantegazza, L. 1987, A&A, 175, 117 Google Scholar
Breger, M., McNamara, B. J., Kerschbaum, F., Huang, L., Jiang, S.-y., Guo, Z.-h., Poretti, E. 1990, A&A 231, 56 Google Scholar
Dziembowski, W. A., and Goode, P. R. 1992, ApJ, in pressGoogle Scholar
Dziembowski, W. A. and Krolikowska, M. 1990, Acta Astron. 40, 19 Google Scholar
Dziembowski, W. A. and Pamyatnykh, A. A. 1991, A&A, 248, Lll Google Scholar
Fitch, W. S. 1981, ApJ, 249, 218 Google Scholar
Guzik, J. A. and Cox, A. N. 1991, in Delta Scuti Newsletter, 3, 6, Vienna: Austrian Acad. Sciences Google Scholar
Kennelly, E. J., Walker, G. A. H. and Hubeny, I. 1991, PASP, 103, 1250 CrossRefGoogle Scholar
Kennelly, E. J., Yang, S., Walker, G. A. H. and Hubeny, I. 1992, PASP, 104, 15 Google Scholar
Petersen, J. O. 1992, A&A, in pressGoogle Scholar
Rodriguez, E., Rolland, A., Lopez de Coca, P., Garrido, R. and Gonzalez-Bedolla, S. F. 1992a, A&AS, in pressGoogle Scholar
Rodriguez, E., Rolland, A., Lopez de Coca, P., Garrido, R. and Mendoza, E. E. 1992b, A&A, in pressGoogle Scholar
Saio, H. 1981, ApJ, 244, 299 Google Scholar
Smith, M. A. 1982, ApJ, 254, 242 Google Scholar
Walraven, Th., Walraven, J. and Balona, L. A. 1992, MNRAS, 254, 59 Google Scholar
Watson, R. D. 1988, A&SS, 140, 255 Google Scholar