Constraining the core-rotation rate in red-giant stars from Kepler space photometry
- Author(s)
- P. G. Beck, J. De Ridder, C. Aerts, T. Kallinger, S. Hekker, R. A. García, B. Mosser, G. R. Davies
- Abstract
Rotation plays a key role in stellar structure and its evolution.
Through transport processes which induce rotational mixing of chemical
species and the redistribution of angular momentum, internal stellar
rotation influences the evolutionary tracks in the Hertzsprung-Russell
diagram. In turn, evolution influences the rotational properties.
Therefore, information on the rotational properties of the deep interior
would help to better understand the stellar evolution. However, as the
internal rotational profile cannot be measured directly, it remains a
major unknown leaving this important aspect of models unconstrained. We
can test for nonrigid rotation inside the stars with asteroseismology.
Through the effect of rotational splitting of non-radial oscillation
modes, we investigate the internal rotation profile indirectly. Red
giants have very slow rotation rates leading to a rotational splitting
on the level of a few tenth of a \muHz. Only from more than 1.5 years of
consecutive data from the NASA Kepler space telescope, these tiny
variations could be resolved. A qualitative comparison to theoretical
models allowed constraining the core-to-surface rotation rate for some
of these evolved stars. In this paper, we report on the first results of
a large sample study of splitting of individual dipole modes.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Katholieke Universiteit Leuven, Radboud University, University of Amsterdam (UvA), University of Birmingham, Université Paris VII - Paris-Diderot, Université de recherche Paris Sciences et Lettres
- Journal
- Astronomische Nachrichten
- Volume
- 333
- Pages
- 967
- ISSN
- 0004-6337
- DOI
- https://doi.org/10.1002/asna.201211787
- Publication date
- 2012
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103004 Astrophysics
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/cb88c3d6-d67e-4890-a480-8ce89a944987