论文标题
金属性对太阳样恒星旋转周期可检测性的影响
Effect of metallicity on the detectability of rotational periods in solar-like stars
论文作者
论文摘要
准确确定恒星旋转周期对于估计恒星年龄以及理解恒星活动和进化很重要。尽管可以确定开普勒场旋转周期中大约三万颗恒星，但有超过十万星，尤其是光度变异性和不规则变化模式，旋转周期未知。在这里，我们研究了金属性对旋转周期可检测性的影响。这是通过合成假设恒星的光曲线来完成的，该恒星与我们的太阳相同，但金属性除外。然后将这些光曲线用作周期确定算法的输入。我们发现，恢复旋转信号的成功率最低接近太阳金属性值。这可以通过面部和现货贡献的补偿效应来解释。此外，从开普勒样品中选择具有近极有效温度的太阳能恒星，近太阳光度变异性以及金属性在M/H = -0.35和m/h = 0.35之间，我们分析了已检测到旋转周期的恒星的比例，该恒星的比例是金属性的功能。与我们的理论估算一致，我们发现了接近太阳金属性的检测率的局部最低限度。我们首次报告了87〜太阳能开普勒星的旋转周期。
Accurate determination of stellar rotation periods is important for estimating stellar ages as well as for understanding stellar activity and evolution. While for about thirty thousand stars in the Kepler field rotation periods can be determined, there are over hundred thousand stars, especially with low photometric variability and irregular pattern of variations, for which rotational periods are unknown. Here, we investigate the effect of metallicity on the detectability of rotation periods. This is done by synthesising light curves of hypothetical stars, which are identical to our Sun, with the exception of the metallicity. These light curves are then used as an input to the period determination algorithms. We find that the success rate for recovering the rotation signal has a minimum close to the solar metallicity value. This can be explained by the compensation effect of facular and spot contributions. In addition, selecting solar-like stars with near-solar effective temperature, near solar photometric variability, and with metallicity between M/H = -0.35 and M/H = 0.35 from the Kepler sample, we analyse the fraction of stars for which rotational periods have been detected as a function of metallicity. In agreement with our theoretical estimate we found a local minimum for the detection fraction close to the solar metallicity. We further report rotation periods of 87~solar-like Kepler stars for the first time.
