Seismic evidence for a rapidly rotating core in a lower-giant-branch star observed with kepler

S. Deheuvels, R. A. García, W. J. Chaplin, S. Basu, H. M. Antia, T. Appourchaux, Othman Benomar, G. R. Davies, Y. Elsworth, Laurent Gizon, M. J. Goupil, D. R. Reese, C. Regulo, J. Schou, T. Stahn, L. Casagrande, J. Christensen-Dalsgaard, D. Fischer, S. Hekker, H. Kjeldsen & 7 others S. Mathur, B. Mosser, M. Pinsonneault, J. Valenti, J. L. Christiansen, K. Kinemuchi, F. Mullally

    Research output: Contribution to journalArticle

    Abstract

    Rotation is expected to have an important influence on the structure and the evolution of stars. However, the mechanisms of angular momentum transport in stars remain theoretically uncertain and very complex to take into account in stellar models. To achieve a better understanding of these processes, we desperately need observational constraints on the internal rotation of stars, which until very recently was restricted to the Sun. In this paper, we report the detection of mixed modes - i.e., modes that behave both as g modes in the core and as p modes in the envelope - in the spectrum of the early red giant KIC7341231, which was observed during one year with the Kepler spacecraft. By performing an analysis of the oscillation spectrum of the star, we show that its non-radial modes are clearly split by stellar rotation and we are able to determine precisely the rotational splittings of 18 modes. We then find a stellar model that reproduces very well the observed atmospheric and seismic properties of the star. We use this model to perform inversions of the internal rotation profile of the star, which enables us to show that the core of the star is rotating at least five times faster than the envelope. This will shed new light on the processes of transport of angular momentum in stars. In particular, this result can be used to place constraints on the angular momentum coupling between the core and the envelope of early red giants, which could help us discriminate between the theories that have been proposed over the last few decades.

    Original languageEnglish (US)
    Article number19
    JournalAstrophysical Journal
    Volume756
    Issue number1
    DOIs
    StatePublished - Jan 1 2012

    Fingerprint

    angular momentum
    stars
    seismic property
    stellar models
    envelopes
    spacecraft
    oscillation
    stellar rotation
    inversions
    oscillations
    profiles
    detection
    need
    inversion
    analysis

    Keywords

    • stars: evolution
    • stars: individual (KIC 7341231)
    • stars: interiors
    • stars: oscillations

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Deheuvels, S., García, R. A., Chaplin, W. J., Basu, S., Antia, H. M., Appourchaux, T., ... Mullally, F. (2012). Seismic evidence for a rapidly rotating core in a lower-giant-branch star observed with kepler. Astrophysical Journal, 756(1), [19]. https://doi.org/10.1088/0004-637X/756/1/19

    Seismic evidence for a rapidly rotating core in a lower-giant-branch star observed with kepler. / Deheuvels, S.; García, R. A.; Chaplin, W. J.; Basu, S.; Antia, H. M.; Appourchaux, T.; Benomar, Othman; Davies, G. R.; Elsworth, Y.; Gizon, Laurent; Goupil, M. J.; Reese, D. R.; Regulo, C.; Schou, J.; Stahn, T.; Casagrande, L.; Christensen-Dalsgaard, J.; Fischer, D.; Hekker, S.; Kjeldsen, H.; Mathur, S.; Mosser, B.; Pinsonneault, M.; Valenti, J.; Christiansen, J. L.; Kinemuchi, K.; Mullally, F.

    In: Astrophysical Journal, Vol. 756, No. 1, 19, 01.01.2012.

    Research output: Contribution to journalArticle

    Deheuvels, S, García, RA, Chaplin, WJ, Basu, S, Antia, HM, Appourchaux, T, Benomar, O, Davies, GR, Elsworth, Y, Gizon, L, Goupil, MJ, Reese, DR, Regulo, C, Schou, J, Stahn, T, Casagrande, L, Christensen-Dalsgaard, J, Fischer, D, Hekker, S, Kjeldsen, H, Mathur, S, Mosser, B, Pinsonneault, M, Valenti, J, Christiansen, JL, Kinemuchi, K & Mullally, F 2012, 'Seismic evidence for a rapidly rotating core in a lower-giant-branch star observed with kepler', Astrophysical Journal, vol. 756, no. 1, 19. https://doi.org/10.1088/0004-637X/756/1/19
    Deheuvels, S. ; García, R. A. ; Chaplin, W. J. ; Basu, S. ; Antia, H. M. ; Appourchaux, T. ; Benomar, Othman ; Davies, G. R. ; Elsworth, Y. ; Gizon, Laurent ; Goupil, M. J. ; Reese, D. R. ; Regulo, C. ; Schou, J. ; Stahn, T. ; Casagrande, L. ; Christensen-Dalsgaard, J. ; Fischer, D. ; Hekker, S. ; Kjeldsen, H. ; Mathur, S. ; Mosser, B. ; Pinsonneault, M. ; Valenti, J. ; Christiansen, J. L. ; Kinemuchi, K. ; Mullally, F. / Seismic evidence for a rapidly rotating core in a lower-giant-branch star observed with kepler. In: Astrophysical Journal. 2012 ; Vol. 756, No. 1.
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    AU - García, R. A.

    AU - Chaplin, W. J.

    AU - Basu, S.

    AU - Antia, H. M.

    AU - Appourchaux, T.

    AU - Benomar, Othman

    AU - Davies, G. R.

    AU - Elsworth, Y.

    AU - Gizon, Laurent

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    AU - Christensen-Dalsgaard, J.

    AU - Fischer, D.

    AU - Hekker, S.

    AU - Kjeldsen, H.

    AU - Mathur, S.

    AU - Mosser, B.

    AU - Pinsonneault, M.

    AU - Valenti, J.

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