The diameter of the CoRoT target HD 49933 - Combining the 3D limb darkening, asteroseismology, and interferometry
The diameter of the CoRoT target HD 49933 - Combining the 3D limb darkening, asteroseismology, and interferometry
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DOI：
10.1051/0004-6361/201117349
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发表时间：
2011-10
影响因子：
6.5
通讯作者：
L. Bigot;D. Mourard;P. Bério;F. Th'evenin;R. Ligi;I. Tallon-Bosc;O. Chesneau;O. Delaa;N. Nardetto;K. Perraut;P. Stee;T. Boyajian;P. Morel;B. Pichon;P. Kervella;F. Schmider;H. Mcalister;T. Brummelaar;S. Ridgway;J. Sturmann;L. Sturmann;N. Turner;C. Farrington;P. J. Goldfinger
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文献类型：
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作者：
L. Bigot;D. Mourard;P. Bério;F. Th'evenin;R. Ligi;I. Tallon-Bosc;O. Chesneau;O. Delaa;N. Nardetto;K. Perraut;P. Stee;T. Boyajian;P. Morel;B. Pichon;P. Kervella;F. Schmider;H. Mcalister;T. Brummelaar;S. Ridgway;J. Sturmann;L. Sturmann;N. Turner;C. Farrington;P. J. Goldfinger
上下文。从内部结构的角度解释恒星脉动取决于对恒星基本参数的了解。长基干涉仪允许我们确定非常精确的恒星半径，这是恒星模型的独立约束，帮助我们在HR图中定位恒星。目标。利用直接干涉法确定角直径和先进的三维（3D）建模，我们推导了CoRoT目标HD 49933的半径，并减少了与地震数据兼容的全球恒星参数空间。方法。VEGA/CHARA光谱干涉仪用于测量恒星的角直径。对表面进行了三维辐射流体动力学模拟，计算了边缘变暗，并从可见性曲线中导出了可靠的直径。其他基本的恒星参数（质量，年龄和Teff）是通过使用包含微观扩散的恒星演化模型拟合大小p模频率分离得到的。结果。我们得到了断臂暗化角直径θLD = 0.445±0.012 mas。利用依巴谷视差，我们得到半径R = 1.42±0.04 R′。相应的适合大、小频率间隔的恒星演化模型质量为1
Context. The interpretation of stellar pulsations in terms of internal structure depends on the knowledge of the fundamental stellar parameters. Long-base interferometers permit us to determine very accurate stellar radii, which are independent constraints for stellar models that help us to locate the star in the HR diagram. Aims. Using a direct interferometric determination of the angular diameter and advanced three-dimensional (3D) modeling, we derive the radius of the CoRoT target HD 49933 and reduce the global stellar parameter space compatible with seismic data. Methods. The VEGA/CHARA spectro-interferometer is used to measure the angular diameter of the star. A 3D radiative hydrodynamical simulation of the surface is performed to compute the limb darkening and derive a reliable diameter from visibility curves. The other fundamental stellar parameters (mass, age, and Teff) are found by fitting the large and small p-mode frequency separations using a stellar evolution model that includes microscopic diffusion. Results. We obtain a limb-darkened angular diameter of θLD = 0.445 ± 0.012 mas. With the Hipparcos parallax, we obtain a radius of R = 1.42 ± 0.04 R� . The corresponding stellar evolution model that fits both large and small frequency separations has a mass of 1