The Role of Turbulent Pressure as a Coherent Pulsational Driving Mechanism: The Case of the δ Scuti Star HD 187547
- Autor(en)
- Victoria Antoci, Margarida S. Cunha, Günter Houdek, Theresa Rank-Lüftinger
- Abstrakt
HD 187547 was the first candidate that led to the suggestion that solar-like oscillations are present in δ Scuti stars. Longer observations, however, show that the modes interpreted as solar-like oscillations have either very long mode lifetimes, longer than 960 days, or are coherent. These results are incompatible with the nature of "pure" stochastic excitation as observed in solar-like stars. Nonetheless, one point is certain: the opacity mechanism alone cannot explain the oscillation spectrum of HD 187547. Here we present new theoretical investigations showing that convection dynamics can intrinsically excite coherent pulsations in the chemically peculiar δ Scuti star HD 187547. More precisely, it is the perturbations of the mean Reynold stresses (turbulent pressure) that drives the pulsations and the excitation takes place predominantly in the hydrogen ionization zone.
- Organisation(en)
- Institut für Astrophysik
- Externe Organisation(en)
- Aarhus University, Universidade do Porto
- Journal
- The Astrophysical Journal
- Band
- 796
- Anzahl der Seiten
- 8
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.1088/0004-637X/796/2/118
- Publikationsdatum
- 12-2014
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie, 103004 Astrophysik
- Schlagwörter
- ASJC Scopus Sachgebiete
- Astronomy and Astrophysics, Space and Planetary Science
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/1838ab9a-3c66-4556-b0d0-2a4d22e1b204