Signs of deep mixing in starspot variability

Author(s)
O. V. Arkhypov, Maxim L. Khodachenko, Manuel Güdel, Colin Johnstone, Theresa Rank-Lüftinger, Helmut Lammer
Abstract

The current knowledge on plasma mixing in stellar interiors is based on theoretical modeling, which calibrates the empirical relations between the mixing and observable stellar parameters. Hence, a model-independent method of studying the mixing process is a desirable, but yet unfounded approach. Here, using a new spectral-correlation method, verified for the Sun, we show that deep mixing is manifested in stellar photometric light curves. We measure the timescales of the stochastic change in the spectral power of rotational variability of hundreds of main-sequence stars from the Kepler mission archive. The discovered proportionality of these timescales to the turnover time of the standard mixing length theory, their consistency with Kolmogorov's theory of turbulence, and the relation with stellar activity provide a new approach to the probing of stellar interiors. This opens a broad perspective for experimental studies of deep mixing and magnetic dynamos in stars.

Organisation(s)
Department of Astrophysics
External organisation(s)
Österreichische Akademie der Wissenschaften (ÖAW), Anuchin Research Institute and Museum of Anthropology, Karl-Franzens-Universität Graz
Journal
Astronomy & Astrophysics
Volume
576
No. of pages
7
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361/201425307
Publication date
04-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/signs-of-deep-mixing-in-starspot-variability(161c8029-ec97-40d7-80c2-d9c32545eabd).html