The excitation of solar-like oscillations in a δSct star by efficient envelope convection

Author(s)
V. Antoci, G. Handler, T. L. Campante, A. O. Thygesen, A. Moya, T. Kallinger, D. Stello, A. Grigahcène, H. Kjeldsen, T. R. Bedding, T. Lüftinger, J. Christensen-Dalsgaard, G. Catanzaro, A. Frasca, P. De Cat, K. Uytterhoeven, H. Bruntt, G. Houdek, D. W. Kurtz, P. Lenz, A. Kaiser, J. van Cleve, C. Allen, B. D. Clarke
Abstract

Delta Scuti (δSct) stars are opacity-driven pulsators with massesof 1.5-2.5Msolar, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy through the outer 30per cent of the star and excites a rich spectrum of resonant acoustic modes. Based on the solar example, with no firm theoretical basis, models predict that the convective envelope in δSct stars extends only about 1per cent ofthe radius, but with sufficient energy to excite solar-like oscillations. This was not observed before the Kepler mission, so the presence of a convective envelope in the models has been questioned.Here we report the detection of solar-like oscillations in theδSct star HD187547, implying that surface convection operates efficiently in stars about twice as massive as the Sun, as the ad hoc models predicted.

Organisation(s)
Department of Astrophysics
External organisation(s)
Universidade do Porto, Aarhus University, Spanish National Research Council (CSIC), The University of Sydney, Istituto Nazionale di Astrofisica - Osservatorio Astrofisico di Catania, Royal Observatory of Belgium, Université Paris VII - Paris-Diderot, University of Central Lancashire, Polish Academy of Sciences (PAS), National Aeronautics & Space Administration (NASA), University of British Columbia (UBC), Katholieke Universiteit Leuven
Journal
Nature
Volume
477
Pages
570-573
ISSN
0028-0836
DOI
https://doi.org/10.1038/nature10389
Publication date
09-2011
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Portal url
https://ucrisportal.univie.ac.at/en/publications/18f19966-038d-4e1a-a2ea-909a6f8de49b