Asteroseismology of α Centauri A evidence of rotational splitting

Michael Bazot, F. Bouchy, H. Kjeldsen, S. Charpinet, M. Laymand, S. Vauclair

    Research output: Contribution to journalArticle

    Abstract

    Context. Asteroseismology provides a unique tool for studying stellar interiors. Recently p modes have been detected on the bright solar-like star α Cen A thanks to high-precision radial-velocity measurements. However, a better characterisation of these p modes is clearly needed to constrain theoretical models. Aims. We observed α Cen A during five nights using the HARPS spectrograph in order to improve our knowledge of the seismic properties of this star. Methods. We performed high-precision radial-velocity sequences and computed the acoustic spectrum of α Cen A. Results. We identify 34 p modes with angular degree l = 0-3 in the frequency range 1.8-2.9 mHz and amplitude range 13-48 cms-1, in agreement with previous seismic studies. We find an enhancement of the frequency scatter with the angular degree l that indicates, considering the high inclination axis of α Cen A, rotational splitting and explains the low values of previously suggested mode lifetimes. We also derive new values for the small separations that take the effect of rotational splitting into account. Conclusions. Our seismic study of α Cen A leads to a list of now well-identified p-mode frequencies and shows the importance of taking the rotation into account in order to properly characterise the p modes even in quite short campaigns.

    Original languageEnglish (US)
    Pages (from-to)295-302
    Number of pages8
    JournalAstronomy and Astrophysics
    Volume470
    Issue number1
    DOIs
    StatePublished - Jul 1 2007

    Fingerprint

    asteroseismology
    seismic property
    acoustics
    radial velocity
    stellar interiors
    stars
    velocity measurement
    night
    lists
    inclination
    spectrographs
    frequency ranges
    life (durability)
    augmentation
    effect
    method

    Keywords

    • Stars: individual: α Centauri A
    • Stars: oscillations
    • Techniques: radial velocities

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Bazot, M., Bouchy, F., Kjeldsen, H., Charpinet, S., Laymand, M., & Vauclair, S. (2007). Asteroseismology of α Centauri A evidence of rotational splitting. Astronomy and Astrophysics, 470(1), 295-302. https://doi.org/10.1051/0004-6361:20065694

    Asteroseismology of α Centauri A evidence of rotational splitting. / Bazot, Michael; Bouchy, F.; Kjeldsen, H.; Charpinet, S.; Laymand, M.; Vauclair, S.

    In: Astronomy and Astrophysics, Vol. 470, No. 1, 01.07.2007, p. 295-302.

    Research output: Contribution to journalArticle

    Bazot, M, Bouchy, F, Kjeldsen, H, Charpinet, S, Laymand, M & Vauclair, S 2007, 'Asteroseismology of α Centauri A evidence of rotational splitting', Astronomy and Astrophysics, vol. 470, no. 1, pp. 295-302. https://doi.org/10.1051/0004-6361:20065694
    Bazot M, Bouchy F, Kjeldsen H, Charpinet S, Laymand M, Vauclair S. Asteroseismology of α Centauri A evidence of rotational splitting. Astronomy and Astrophysics. 2007 Jul 1;470(1):295-302. https://doi.org/10.1051/0004-6361:20065694
    Bazot, Michael ; Bouchy, F. ; Kjeldsen, H. ; Charpinet, S. ; Laymand, M. ; Vauclair, S. / Asteroseismology of α Centauri A evidence of rotational splitting. In: Astronomy and Astrophysics. 2007 ; Vol. 470, No. 1. pp. 295-302.
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