Searching For Transiting Planets Around Halo Stars. I. Sample Selection and Validation
Searching For Transiting Planets Around Halo Stars. I. Sample Selection and Validation
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DOI：
10.3847/1538-3881/ac14bc
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发表时间：
2021-06
期刊：
影响因子：
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通讯作者：
Jared R. Kolecki;J. Wang 王;Jennifer A. Johnson;J. Zinn;I. Ilyin;K. Strassmeier
中科院分区：
文献类型：
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作者：
Jared R. Kolecki;J. Wang 王;Jennifer A. Johnson;J. Zinn;I. Ilyin;K. Strassmeier
通过测量一颗恒星的元素丰度，我们可以深入了解其初始气体云的组成——这是恒星及其行星的形成地点。行星的形成需要金属，而金属的可用性取决于元素的丰度。在金属极度缺乏的情况下，行星的形成可能会受到抑制。要研究这种情况，需要大量的贫金属恒星样本，并在其中寻找行星。本文重点研究了一颗晕星样品的选择与验证。我们根据它们的银河系运动学选择了~ 17000颗金属贫乏的晕星，并使用文献中的光谱学证实了它们的低金属丰度（[Fe/H] < - 0.5）。此外，我们使用LBT/PEPSI进行了高分辨率光谱观测，并对13颗已知的同样具有热运动学的晕星样本进行了详细的金属丰度（[Fe/H]）分析。我们可以使用这里展示的光晕恒星样本来测量行星的频率，并测试在极度缺乏金属的环境中行星的形成。行星搜索的结果及其影响将在Boley等人的配套论文中提出和讨论。
By measuring the elemental abundances of a star, we can gain insight into the composition of its initial gas cloud—the formation site of the star and its planets. Planet formation requires metals, the availability of which is determined by the elemental abundance. In the case where metals are extremely deficient, planet formation can be stifled. To investigate such a scenario requires a large sample of metal-poor stars and a search for planets therein. This paper focuses on the selection and validation of a halo star sample. We select ∼17,000 metal-poor halo stars based on their Galactic kinematics, and confirm their low metallicities ([Fe/H] < −0.5), using spectroscopy from the literature. Furthermore, we perform high-resolution spectroscopic observations using LBT/PEPSI and conduct detailed metallicity ([Fe/H]) analyses on a sample of 13 previously-known halo stars that also have hot kinematics. We can use the halo star sample presented here to measure the frequency of planets and to test planet formation in extremely metal-poor environments. The result of the planet search and its implications will be presented and discussed in a companion paper by Boley et al.