论文标题
恒星年龄和现场覆盖范围之间的关系
A Relationship Between Stellar Age and Spot Coverage
论文作者
论文摘要
我们研究了星形分布与六个恒星关联的F，G和K星的空间光度法一致，年龄从10 MYR到4 GYR不等。我们表明，在类似Skumanich的旋转关系之后，一个简单的光曲线统计量称为“平滑振幅”与恒星年龄成正比为$ t^{ - 1/2} $。我们通过向前建模光曲线的集合来直接与开普勒，K2和苔丝光度法进行直接比较，从而在未知的恒星倾斜上边缘化。我们通过近似贝叶斯计算进行了后验分布以进行斑点覆盖。我们发现在1-10％的范围内典型的覆盖范围，随着恒星年龄的增加而降低。现货覆盖范围与$ t^n $成正比，其中$ n = -0.37 \ pm 0.16 $，在统计上也与类似于Skumanich的$ t^{ - 1/2} $衰减的星形覆盖范围随着年龄的增长而统计。我们采用两种技术来估计詹姆斯·韦伯（James Webb）空间望远镜可能针对传输光谱的年轻系外行星托管星的斑点，并估计由于星形平面覆盖率变化而导致的系外行星半径测量值的偏差。
We investigate starspot distributions consistent with space-based photometry of F, G, and K stars in six stellar associations ranging in age from 10 Myr to 4 Gyr. We show that a simple light curve statistic called the "smoothed amplitude" is proportional to stellar age as $t^{-1/2}$, following a Skumanich-like spin-down relation. We marginalize over the unknown stellar inclinations by forward modeling the ensemble of light curves for direct comparison with the Kepler, K2 and TESS photometry. We sample the posterior distributions for spot coverage with Approximate Bayesian Computation. We find typical spot coverages in the range 1-10% which decrease with increasing stellar age. The spot coverage is proportional to $t^n$ where $n =-0.37 \pm 0.16$, also statistically consistent with a Skumanich-like $t^{-1/2}$ decay of starspot coverage with age. We apply two techniques to estimate the spot coverage of young exoplanet-hosting stars likely to be targeted for transmission spectroscopy with the James Webb Space Telescope, and estimate the bias in exoplanet radius measurements due to varying starspot coverage.
