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Evidence for global pressure oscillations in Procyon and α Centauri

Published online by Cambridge University Press:  03 August 2017

B. Gellt ,
G. Grec  and
E. Fossat
B. Gellt
Affiliation:
Département d'Astrophysique de l'MSP, Université de Nice, Parc Valrose, F - 06034 NICE CEDEZ
G. Grec
Affiliation:
Département d'Astrophysique de l'MSP, Université de Nice, Parc Valrose, F - 06034 NICE CEDEZ
E. Fossat
Affiliation:
Département d'Astrophysique de l'MSP, Université de Nice, Parc Valrose, F - 06034 NICE CEDEZ

Abstract

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Helioseismology bas proved to be a powerful tool to probe the internal structure of the sun. With a new adapted optical resonance spectrophotometer, an extension has been attempted to two bright stars, namely α Centauri Å and Procyon. Results obtained from two observing runs on α Centauri Å in May 1983 and May 1984 at La Silla, and one observing run on Procyon in February 1984 at Hawaii are presented. In both cases, solar-like pressure oscillations have been detected. The complete analysis is presented, which leads to determine essentially five parameters: the frequency range, the amplitudes, the mean equidistance Δν, the departure around this equidistance (curvature of the echelle-diagram) and the fine frequency spacing between modes of degree 0 and 2. For Procyon, all results are consistent with theoretical predictions, including excitation of oscillations, mass, radius, and age of the star. For α Centauri, all the results are consistent together and are confirmed by the 1984 observations. They suggest that α Cen might be younger than estimated, consistent with a zero age main sequence star.

This is the abstract of a paper recently published in Astronomy and Astrophysics. We have selected here under some parts of this paper. For more detail, it is recommended to refer to this journal.

Type
Chapter 4: Asteroseismology: Results and Prospects
Information
Symposium - International Astronomical Union , Volume 123: Advances In Hello- and Asteroseismology , 1988 , pp. 249 - 252
Copyright
Copyright © Reidel 1988 

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