Fundamental properties of five Kepler stars using global asteroseismic quantities and ground-based observations-猫眼课题宝

DOI：

10.1051/0004-6361/201117037

发表时间：

2011-11

期刊：

Astronomy and Astrophysics

影响因子：

6.5

通讯作者：

中科院分区：

物理与天体物理2区

文献类型：

作者：

O. Creevey;G. Doğan;A. Frasca;A. Thygesen;S. Basu;J. Bhattacharya;K. Brandao;H. Bruntt;A. Mazumdar;E. Niemczura;T. Shrotriya;S. Sousa;D. Stello;A. Subramaniam;T. Campante;R. Handberg;S. Mathur;T. Bedding;R. Garc'ia;C. R'egulo;D. Salabert;J. Molenda–Żakowicz;P. Quirion;T. White;A. Bonanno;W. Chaplin;J. Christensen-Dalsgaard;J. Christiansen;Y. Elsworth;M. Fanelli;C. Karoff;K. Kinemuchi;H. Kjeldsen;N. Gai;M. Monteiro;J. C. S. Iac;Spain.;Ull;Oca;France.;Au;Denmark;Hao;Usa;INAF-Catania;Italy.;Nőt;L. Palma;Yale;Iitk;India.;INAF-Napoli;Caup;Portugal;DFA-UP;HBCSE-Mumbai;IA-Wroclaw;Poland;IISERP-Pune;Sifa;Australia.;IITM-Chennai;Cea;Csa;Canada.;U.Birmingham;UK.;SETI-CA;B. Arc;U. Dezhou;China.;ıaa

我们提出了一个类太阳恒星KIC 11395018，KIC 10273246，KIC 10920273，KIC 10339342，和KIC 11234888使用短节奏的时间序列，从开普勒卫星超过8个月的星震研究。对于其中四颗恒星，我们从北欧光学望远镜获得的光谱中获得大气参数。全球地震量（平均大频率间隔和最大功率频率），结合大气参数，产生的平均密度和表面重力的精度分别为2%和10.03 dex。我们还使用基于网格的分析确定了半径，质量和年龄，精度分别为2 - 5%，7 - 11%和35%。将恒星参数与光度测量数据相结合，可以得到精度优于10%的星震距离。一个vsini测量提供了一个旋转周期倾角的相关性，并使用最近的文献中的旋转周期，我们约束的恒星倾角为三颗恒星。一个锂丰度分析产生了一个独立的年龄估计，但这是不一致的星震确定的年龄之一。我们评估了五种基于网格的分析方法的性能，发现它们都能在大气和地震约束条件下提供一致的表面重力值，达到0.03 dex。不同的基于网格的分析都产生半径和质量的拟合值在2.4σ内，并取这些结果的平均值将其降低到1.5σ。当以1%的精度测量平均大频率间隔时，没有金属丰度约束会使具有非太阳金属丰度的恒星（富金属KIC 11395018和贫金属KIC 10273246）的拟合半径和质量产生偏差，而包括金属丰度约束会使这两个参数的不确定性降低近两倍。我们发现，包括平均小的频率分离，提高了确定的年龄只为KIC 11395018和KIC 11234888，而对于后者，这种改善是由于缺乏强大的大气约束。

We present an asteroseismic study of the solar-like stars KIC 11395018, KIC 10273246, KIC 10920273, KIC 10339342, and KIC 11234888 using short-cadence time series of more than eight months from the Kepler satellite. For four of these stars, we derive atmospheric parameters from spectra acquired with the Nordic Optical Telescope. The global seismic quantities (average large frequency separation and frequency of maximum power), combined with the atmospheric parameters, yield the mean density and surface gravity with precisions of 2% and ∼0.03 dex, respectively. We also determine the radius, mass, and age with precisions of 2‐5%, 7‐11%, and ∼35%, respectively, using grid-based analyses. Coupling the stellar parameters with photometric data yields an asteroseismic distance with a precision better than 10%. A vsini measurement provides a rotational period-inclination correlation, and using the rotational periods from the recent literature, we constrain the stellar inclination for three of the stars. An Li abundance analysis yields an independent estimate of the age, but this is inconsistent with the asteroseismically determined age for one of the stars. We assess the performance of five grid-based analysis methods and find them all to provide consistent values of the surface gravity to ∼0.03 dex when both atmospheric and seismic constraints are at hand. The different grid-based analyses all yield fitted values of radius and mass to within 2.4σ, and taking the mean of these results reduces it to 1.5σ. The absence of a metallicity constraint when the average large frequency separation is measured with a precision of 1% biases the fitted radius and mass for the stars with non-solar metallicity (metal-rich KIC 11395018 and metal-poor KIC 10273246), while including a metallicity constraint reduces the uncertainties in both of these parameters by almost a factor of two. We found that including the average small frequency separation improves the determination of the age only for KIC 11395018 and KIC 11234888, and for the latter this improvement was due to the lack of strong atmospheric constraints.

Fundamental properties of five Kepler stars using global asteroseismic quantities and ground-based observations

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