Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-12T18:55:15.565Z Has data issue: false hasContentIssue false
  • English
  • Français

Theoretical Aspects of the Rapidly Oscillating AP Stars

Published online by Cambridge University Press:  14 August 2015

H. Shibahashi
H. Shibahashi*
Affiliation:
Department of Astronomy, University of TokyoTokyo 113-0032, Japan

Extract

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.

Until the rapid oscillations in Przybylski’s star, HD 101065, were discovered by Kurtz in 1978, chemical peculiarity and pulsation were thought to be mutually exclusive. Though the location of the Ap stars in the HR diagram overlaps with that of the Delta Scuti stars, no Ap stars were known to pulsate, and the Delta Scuti type pulsating stars, with a few exceptions, were not claimed to reveal chemical peculiarity. The striking impact of the discovery of the rapid oscillations of Ap stars is that the basic conception of the exclusiveness of the chemical peculiarity and the pulsation was broken. So far, twenty-nine Ap stars have been discovered to be rapidly oscillating Ap (roAp) stars (Kurtz 1997). The observed pulsations of Ap stars are, however, different from those of the Delta Scuti stars in various aspects. The pulsation periods of roAp stars are typically 10.minutes and are much shorter than those of the Delta Scuti stars, which are typically 2 hrs. In some cases, the amplitudes are modulated with the same period and phase as the magnetic strength variation. The amplitudes of some of the roAp stars are very stable, while some others show a fairly short-term variation of a time scale of a day. Some of the roAp stars show a long-term variation of the frequency with a time scale of years.

Type
II. Joint Discussions
Information
Highlights of Astronomy , Volume 11 , Issue 2: Highlights of Astronomy. As presented at the XXIIIrd General Assembly of the IAU (Part B), 1997 , 1998 , pp. 686 - 688
Copyright
Copyright © Kluwer 1998

References

Audard, N., Kupka, F., Morel, P., Provost, J., and Weiss, W. W. (1997), Astron. Astrophys., submitted.Google Scholar
Dziembowski, W. A. and Goode, P. R. (1986), Astrophys. J., 296, L27.Google Scholar
Dziembowski, W. A. and Goode, P. R. (1996), Astrophys. J., 458, 338.Google Scholar
Gautschy, A. and Saio, H. (1997), in Proc. IAU Symp. No. 185, New Eyes to See Inside the Sun and Stars, ed. Deubner, F.-L., Christenscn-Dalsgaard, J. and Kurtz, D. W. (Dordrecht: Kluwer), in press.Google Scholar
Kurtz, D. W. (1978), Inf. Bull. Var. Stars, 1436.Google Scholar
Kurtz, D. W. (1982), Monthly Notices Roy. Astron. Soc., 200, 807.Google Scholar
Kurtz, D. W. (1992), Monthly Notices Roy. Astron. Soc, 259, 701.Google Scholar
Kurtz, D. W. (1997), in Proc. IAU Symp. No. 185, New Eyes to See Inside the Sun and Stars, ed. Deubner, F.-L., Christensen-Dalsgaard, J. and Kurtz, D. W. (Dordrecht: Kluwer), in press.Google Scholar
Kurtz, D. W. and Shibahashi, H. (1986), Monthly Notices Roy. Astron. Soc., 223, 557.Google Scholar
Matthews, J. (1988), Monthly Notices Roy. Astron. Soc, 235, 7p.Google Scholar
Shibahashi, H. (1984), Astrophys. J., 275, L5.Google Scholar
Shibahashi, H. and Saio, H. (1985), Publ. Astron. Soc Japan, 37, 245.Google Scholar
Shibahashi, H. and Takata, M. (1993), Publ. Astron. Soc. Japan, 45, 617.Google Scholar
Takata, M. and Shibahashi, H. (1995), Publ. Astron. Soc. Japan, 47, 219.Google Scholar
Tassoni, M. (1980), Astrophys. J. Suppl, 43, 469.Google Scholar
Vauclair, S., Dolez, N., and Gough, D. O. (1991), Astron. Astrophys., 252, 618.Google Scholar