标题： 太阳孪生星和类似恒星中的钍丰度：对太阳系外行星系统的宜居性的影响 显示英文标题

标题： Thorium Abundances in Solar Twins and Analogues: Implications for the Habitability of Extrasolar Planetary Systems

摘要： 我们首次研究了太阳系孪生星和类似星的钍丰度，以了解这种放射性元素可能的范围及其对类地行星内部动力学和潜在宜居性的影响。 放射性元素钍（Th）和铀（U）的丰度是行星能量预算的关键组成部分，占地球的30%到50%（Korenaga 2008；Allègre等 2001；Schubert等 1980；Lyubetskaya & Korenaga 2007；KamLAND 合作组 2011；Huang等 2013）。 放射热驱动地幔对流和地表板块构造运动，维持深碳循环和水循环，从而有助于形成地球的宜居表面。 与其他依赖行星特定形成历史的热源不同，放射热预算直接与这些核素的地幔浓度相关。 作为难熔元素，钍的恒星丰度忠实反映了类地行星的浓度。 我们发现，钍的log eps 值变化范围从太阳的59%到251%，表明太阳系外的行星系统可能拥有更大的能量预算，支持表面到内部的动力学，从而增加其宜居的可能性，相比我们的太阳系。 显示英文摘要

摘要： We present the first investigation of Th abundances in Solar twins and analogues to understand the possible range of this radioactive element and its effect on rocky planet interior dynamics and potential habitability. The abundances of the radioactive elements Th and U are key components of a planet's energy budget, making up 30% to 50% of the Earth's (Korenaga 2008; All\`egre et al. 2001; Schubert et al. 1980; Lyubetskaya & Korenaga 2007; The KamLAND Collaboration 2011; Huang et al. 2013). Radiogenic heat drives interior mantle convection and surface plate tectonics, which sustains a deep carbon and water cycle and thereby aides in creating Earth's habitable surface. Unlike other heat sources that are dependent on the planet's specific formation history, the radiogenic heat budget is directly related to the mantle concentration of these nuclides. As a refractory element, the stellar abundance of Th is faithfully reflected in the terrestrial planet's concentration. We find that log eps Th varies from 59% to 251% that of Solar, suggesting extrasolar planetary systems may possess a greater energy budget with which to support surface to interior dynamics and thus increase their likelihood to be habitable compared to our Solar System.