Investigating the Properties of Granulation in the Red Giants Observed by Kepler

Autor(en)

S. Mathur, S. Hekker, R. Trampedach, J. Ballot, T. Kallinger, D. Buzasi, R. A. García, D. Huber, A. Jiménez, B. Mosser, T. R. Bedding, Y. Elsworth, C. Régulo, D. Stello, W. J. Chaplin, J. De Ridder, S. J. Hale, K. Kinemuchi, H. Kjeldsen, F. Mullally, S. E. Thompson

Abstrakt

More than 1000 red giants have been observed by NASA/Kepler missionduring a nearly continuous period of ˜ 13 months. The resultinghigh-frequency resolution (<0.03 μHz) allows us to study thegranulation parameters of these stars. The granulation pattern resultsfrom the convection motions leading to upward flows of hot plasma anddownward flows of cooler plasma. We fitted Harvey-like functions to thepower spectra, to retrieve the timescale and amplitude of granulation.We show that there is an anti-correlation between both of theseparameters and the position of maximum power of acoustic modes, while wealso find a correlation with the radius, which agrees with the theory.We finally compare our results with 3D models of the convection.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

National Center for Atmospheric Research (NCAR), University of Amsterdam (UvA), University of Birmingham, University of Colorado, Boulder, Université de Toulouse, Katholieke Universiteit Leuven, Eureka Scientific Inc., Université Paris VII - Paris-Diderot, The University of Sydney, Universidad de La Laguna, Université de recherche Paris Sciences et Lettres, National Aeronautics & Space Administration (NASA), Aarhus University

Journal

Astronomical Society of the Pacific Conference Series

Band

462

Seiten

375

ISSN

1050-3390

Publikationsdatum

09-2012

ÖFOS 2012

103004 Astrophysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/306906a5-752d-4ccb-ac16-e3866c223b17