Constraining the core-rotation rate in red-giant stars from Kepler space photometry

Autor(en)

P. G. Beck, J. De Ridder, C. Aerts, T. Kallinger, S. Hekker, R. A. García, B. Mosser, G. R. Davies

Abstrakt

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(en)

Institut für Astrophysik

Externe Organisation(en)

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

Band

333

Seiten

967

ISSN

0004-6337

DOI

https://doi.org/10.1002/asna.201211787

Publikationsdatum

2012

Peer-reviewed

Ja

ÖFOS 2012

103004 Astrophysik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/cb88c3d6-d67e-4890-a480-8ce89a944987