THE ROLE OF TURBULENT PRESSURE AS A COHERENT PULSATIONAL DRIVING MECHANISM: THE CASE OF THE delta SCUTI STAR HD 187547

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Antoci, V (Author) Other; Cunha, MS (Author) FCUP; Houdek, G (Author) Other; Kjeldsen, H (Author) Other; Trampedach, R (Author) Other; Handler, G (Author) Other; Lueftinger, T (Author) Other; Arentoft, T (Author) Other; Murphy, S (Author) Other

Journal

Title: Astrophysical Journal

Vol. 796

Final page: 118

ISSN: 0004-637X

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 43 Citations

Scopus - 41 Citations

Other information

Authenticus ID: P-009-YT6

DOI: 10.1088/0004-637x/796/2/118

Abstract (EN): HD 187547 was the first candidate that led to the suggestion that solar-like oscillations are present in delta 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 delta 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8