期刊
ASTRONOMY & ASTROPHYSICS
卷 590, 期 -, 页码 -出版社
EDP SCIENCES S A
DOI: 10.1051/0004-6361/201527920
关键词
stars: fundamental parameters; stars: individual: HD 24712; techniques: high angular resolution; techniques: interferometric
资金
- French program for stellar physics and high angular resolution PNPS
- French program for stellar physics and high angular resolution ASHRA
- Nice Observatory
- Lagrange Department
- NSF grants [AST-0908253, AST 1211129]
- Georgia State University through the College of Arts and Sciences
- LabEx OSUG@2020 (Investissements d'avenir) [ANR10LABX56]
- ERC [FP7-SPACE-2012-312844]
- FCT [SFRH/BPD/87857/2012]
- Fundacao para a Ciencia e a Tecnologia (FCT) [IF/00894/2012, UID/FIS/04434/2013]
- POPH/FSE (EC) through FEDER through the program COMPETE
- EC, under FP7 [FP7-SPACE-2012-312844]
- CRC 963 - Astrophysical Flow Instabilities and Turbulence [A16-A17]
- Fizeau optical interferometry program [2015B]
- Fundação para a Ciência e a Tecnologia [SFRH/BPD/87857/2012] Funding Source: FCT
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1211929] Funding Source: National Science Foundation
Context. There is still a debate about the nature of the mechanism that causes the pulsation excitation of the rapidly oscillating Ap stars that oscillate above the highest theoretically acoustic frequency. HD 24712 is a good test case for such a study because it is bright, its parallax accurately determined, and its frequency spectrum is well known. Aims. Visible long-baseline interferometry is a unique technique for measuring accurate angular diameters of targets as small as the brightest roAp stars, and thus estimating accurate radii by a method as independent as possible of atmosphere models. Methods. We used the visible spectrograph VEGA at the CHARA long-baseline optical array to observe HD 24712, and we derived its limb-darkened diameter. We also estimated its bolometric flux from spectroscopic data in the literature and determined its radius, luminosity, and effective temperature. Results. We determined a limb-darkened angular diameter of 0.335 +/- 0.009 mas for HD 24712 and derived a radius of R = 1.772 +/- 0.057 R-circle dot, a luminosity of L = 7.2 +/- 1.8 L-circle dot, and an effective temperature of T-eff = 7235 +/- 280 K, which is in very close agreement with the values provided by the self-consistent stratified model developed for this star. We used these fundamental parameters to set HD 24712 in the Hertzsprung-Russell diagram. Its position is marginally consistent with the region where high radial order modes are predicted to be excited by the kappa-mechanism. Conclusions. We conclude that oscillations in this star are most likely not driven by the kappa-mechanism.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据