Advertisement

Toward seismology of δ Scuti stars

  • W. Dziembowski
Part IV Seismology of the Stars
Part of the Lecture Notes in Physics book series (LNP, volume 367)

Abstract

Many among δ Scuti variables were shown to be multiperiodic and all of them probably are. Being in various stages of early evolutionary phase these stars seem excellent candidates for seismic testing the basic assumptions and physics of the stellar evolution theory. What hinders any major progress in the field is an unresolved problem of connecting sparse spectra of the observed oscillation frequencies to dense spectra calculated for the models. Determination of the rotation rate in the interior is probably the most important goal of asteroseismology. In the case of δ Scuti stars there is a complication following from the high density of the spectrum that the standard formula for the rotational splitting may not be valid. To understand mode selection mechanism we have to go beyond the linear adiabatic theory of stellar oscillations. There are still uncertainties in determining mode stability, but the real difficulty lies in prediction which of many unstable models may reach detectable amplitudes. Trapping in the envelope is a possible mechanism of mode selection, but it is not clear yet whether it finds support in observational data. Observational information on spherical harmonics associated with the observed periodicities is crucial for mode identification. This was obtained with use of both photometric and spectroscopic data for number of δ Scuti stars. There are, however, uncertainties which must be clarified with new data and improved methods of their analysis. Efforts in obtaining periodograms for unevolved objects having simple theoretical frequency spectra are encouraged.

Keywords

Unstable Mode Mode Identification Radial Mode Star Model Monthly Notice 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Andreasen, G.K., and Petersen, S.O. 1988, Asrtron. Astrophys., 192, L4.Google Scholar
  2. Balona, L.A. 1986a, Monthly Notices Roy. Astron. Soc., 219, 111.Google Scholar
  3. Balona, L.A. 1986b, Monthly Notices Roy. Astron. Soc., 220, 647.Google Scholar
  4. Balona, L.A., and Stobie, R.S. 1979, Monthly Notices Roy. Astron. Soc., 189, 649.Google Scholar
  5. Berthomieu, G., Gonczi, G., Graff, P., Provost, J., and Rocca, A. 1978, Asrtron. Astrophys., 70, 597.Google Scholar
  6. Breger, M., McNamara, B.J., Kerschbaum, Ling, H., Shi-yang, J., Zi-he, G., and Poretti, E. 1990, Asrtron. Astrophys., in press.Google Scholar
  7. Brown, T.M., Christensen-Dalsgaard, J., Dziembowski, W.A., Goode, P., Gough, D.O., and Morrow, C.A. 1989, Astrophys. J, 343, 526.CrossRefGoogle Scholar
  8. Christensen-Dalsgaard, J., Gough, D.O., and Thompson, M.J. 1988, in Seismology of the Sun and Sun-like Stars, ed. E.J. Rolfe, ESA SP-286 (ESA Publication Division, Noordwijk), p.493.Google Scholar
  9. Cox, A.N., King, D.S., and Hodson, S.W. 1979, Astrophys. J, 231, 798.Google Scholar
  10. Dziembowski, W. 1975, Mem. Soc. Roy. Sci. Liège, 8, 289.Google Scholar
  11. Dziembowski, W. 1977a, Acta Astron., 27, 95.Google Scholar
  12. Dziembowski, W. 1977b, Acta Astron., 27, 203.Google Scholar
  13. Dziembowski, W. 1980, in Nonradial and Nonlinear Stellar Pulsation, eds. H.A. Hill and W.A. Dziembowski (Springer, Berlin), p.22.Google Scholar
  14. Dziembowski, W., and Królikowska, M. 1985, Acta Astron., 35, 5.Google Scholar
  15. Dziembowski, W., and Królikowska, M. 1990, Acta Astron., in press.Google Scholar
  16. Dziembowski, W., Królikowska, M., and Kosovichev, A. 1988, Acta Astron., 38, 5.Google Scholar
  17. Fitch, W.S. 1981, Astrophys. J, 249, 218.Google Scholar
  18. Kovács,G., and Paparó, M. 1989, Monthly Notices Roy. Astron. Soc., 237, 355.Google Scholar
  19. Krolikowska, M. 1988, Ph.D. Thesis, (Copernicus Astronomical Center, Warsaw).Google Scholar
  20. Kurtz, D.W. 1988, in Multimode Stellar Pulsations, eds G. Kovacs, L. Szabados, and B. Szeidl (Kultura, Budapest), p.95.Google Scholar
  21. Ledoux, P. 1951, Astrophys. J., 114, 373.CrossRefGoogle Scholar
  22. Lee, U. 1985, Publ. Astron. Soc. Japan, 37, 279.Google Scholar
  23. Mageney, A., Cheverton, Belmonte, J.A., Däppen, W., Saint-Pé, O., Praderie, F., Roca Cortès, Fuensalinda, J, and Alvarez, M. 1988, in Seismology of the Sun and Sun-like Stars, ed. E.J. Rolfe, ESA SP-286 (ESA Publication Division, Noordwijk), p.551.Google Scholar
  24. Moskalik, P. 1986, Acta Astron., 36, 333.Google Scholar
  25. Saio, H. 1981, Astrophys. J, 249, 299.CrossRefGoogle Scholar
  26. Simon, N.R. 1982, Astrophys. J. Letters, 260, L87.Google Scholar
  27. Smith, M.A. 1982, Astrophys. J, 254, 242.Google Scholar
  28. Stellingwerf, R.F. 1979, Astrophys. J, 227, 935.Google Scholar
  29. Watson, R.D. 1988, Astrophys. Space Sci., 140, 255.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • W. Dziembowski
    • 1
  1. 1.Nicolaus Copernicus Astronomical CenterWarsawPoland

Personalised recommendations