Asteroseismology of KIC 11754974: a high-amplitude SX Phe pulsator in a 343-day binary system

Дата и время публикации : 2013-04-04T20:00:03Z

Авторы публикации и институты :
S. J. Murphy
A. Pigulski
D. W. Kurtz
J. C. Suarez
G. Handler
L. A. Balona
B. Smalley
K. Uytterhoeven
R. Szabo
A. O. Thygesen
V. Elkin
M. Breger
A. Grigahcene
J. A. Guzik
J. M. Nemec
J. Southworth

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 15 pages, 6 tables, 11 figures of which 7 are colour (suitable for greyscale printing). Accepted for publication in MNRAS
Первичная категория: astro-ph.SR

Все категории : astro-ph.SR

Краткий обзор статьи: The candidate SX Phe star KIC 11754974 shows a remarkably high number of combination frequencies in the Fourier amplitude spectrum: 123 of the 166 frequencies in our multi-frequency fit are linear combinations of independent modes. Predictable patterns in frequency spacings are seen in the Fourier transform of the light curve. We present an analysis of 180 d of short-cadence Kepler photometry and of new spectroscopic data for this evolved, late A-type star. We infer from the 1150-d, long-cadence light curve, and in two different ways, that our target is the primary of a 343-d, non-eclipsing binary system. According to both methods, the mass function is similar, f(M)=0.0207 +/- 0.0003 Msun. The observed pulsations are modelled extensively, using separate, state-of-the-art, time-dependent convection (TDC) and rotating models. The models match the observed temperature and low metallicity, finding a mass of 1.50-1.56 Msun. The models suggest the whole star is metal-poor, and that the low metallicity is not just a surface abundance peculiarity. This is the best frequency analysis of an SX Phe star, and the only Kepler delta Sct star to be modelled with both TDC and rotating models.

Category: Physics