A seismic and gravitationally bound double star observed by Kepler. Implication for the presence of a convective core
A seismic and gravitationally bound double star observed by Kepler. Implication for the presence of a convective core
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DOI：
10.1051/0004-6361/201526610
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发表时间：
2015-10
影响因子：
6.5
通讯作者：
T. Appourchaux;H. M. Antia;W. Ball;O. Creevey;Y. Lebreton;K. Verma;S. Vorontsov;T. Campante;G. Davies;P. Gaulme;C. Régulo;E. Horch;S. Howell;M. Everett;D. Ciardi;L. Fossati;A. Miglio;J. Montalbán;W. Chaplin;R. García;L. Gizon
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文献类型：
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作者：
T. Appourchaux;H. M. Antia;W. Ball;O. Creevey;Y. Lebreton;K. Verma;S. Vorontsov;T. Campante;G. Davies;P. Gaulme;C. Régulo;E. Horch;S. Howell;M. Everett;D. Ciardi;L. Fossati;A. Miglio;J. Montalbán;W. Chaplin;R. García;L. Gizon
上下文开普勒和CoRoT已经在许多太阳型恒星中观测到了类似太阳的振荡，从而提供了一种使用星震学探测恒星的方法。恒星参数的推导通常是用单颗恒星进行的。本文的目的是推导出一个双星系统（HIP 93511）的恒星参数，它的干涉轨道已被观测到沿着的星震测量。我们利用双星星星近两年的时间序列数据来检测功率谱中出现的两个振荡模式包络。利用一种新的基于光度的标度关系，我们导出了每颗星星的半径和质量。我们使用两个代理人推导出每颗星星的年龄：一个基于大的频率间隔，另一个基于小的频率间隔。使用恒星模型，模式频率使我们能够推导出每个组件的半径，质量和年龄。此外，自2006年以来进行的散斑干涉术使我们能够恢复系统的轨道和系统的总质量。根据轨道的测定，该系统的总质量为2.34-0.33+0.45 M。使用比例关系得到的总地震质量为2.47 ± 0.07 M Ω。根据小频率间隔的新代用指标计算的地震年龄为3.5 ± 0.3 Gyr。根据恒星模型，该系统的平均共同年龄为2.7-3.9 Gyr。该系统的平均总地震质量为2.34-2.53 M，与我们独立测定的轨道一致。恒星模型提供了恒星的平均半径、质量和年龄：RA = 1.82− 1.87 R，MA = 1.25−1.39 M，A = 2.6-3.5 Gyr; RB = 1.22−1.25 R，MB = 1.08−1.14 M，B = 3.35-4.21 Gyr。该模型为星星A提供了两组数值：[1.25-1.27] M和[1.34-1.39] M。我们在星星A中检测到对流核心，而星星B没有任何对流核心。对于双星系统Z = 0.02的金属丰度，我们将对流核的恒星之间的界限设定在[1.14-1.25] M <$。
Context. Solar-like oscillations have been observed by Kepler and CoRoT in many solar-type stars, thereby providing a way to probe stars using asteroseismology.Aims. The derivation of stellar parameters has usually been done with single stars. The aim of the paper is to derive the stellar parameters of a double-star system (HIP 93511), for which an interferometric orbit has been observed along with asteroseismic measurements.Methods. We used a time series of nearly two years of data for the double star to detect the two oscillation-mode envelopes that appear in the power spectrum. Using a new scaling relation based on luminosity, we derived the radius and mass of each star. We derived the age of each star using two proxies: one based upon the large frequency separation and a new one based upon the small frequency separation. Using stellar modelling, the mode frequencies allowed us to derive the radius, the mass, and the age of each component. In addition, speckle interferometry performed since 2006 has enabled us to recover the orbit of the system and the total mass of the system.Results. From the determination of the orbit, the total mass of the system is 2.34-0.33+0.45 M⊙. The total seismic mass using scaling relations is 2.47 ± 0.07 M⊙. The seismic age derived using the new proxy based upon the small frequency separation is 3.5 ± 0.3 Gyr. Based on stellar modelling, the mean common age of the system is 2.7–3.9 Gyr. The mean total seismic mass of the system is 2.34–2.53 M⊙ consistent with what we determined independently with the orbit. The stellar models provide the mean radius, mass, and age of the stars as RA = 1.82−1.87R⊙, MA = 1.25−1.39 M⊙, AgeA = 2.6–3.5 Gyr; RB = 1.22−1.25 R⊙, MB = 1.08−1.14 M⊙, AgeB = 3.35–4.21 Gyr. The models provide two sets of values for Star A: [1.25–1.27] M⊙ and [1.34–1.39] M⊙. We detect a convective core in Star A, while Star B does not have any. For the metallicity of the binary system of Z ≈ 0.02, we set the limit between stars having a convective core in the range [1.14–1.25] M⊙.