The mantra “know thy star, know thy planet” has proven to be very important for many aspects of exoplanet science. Here I review how stellar abundances inform our understanding of planet composition and, thus, formation and evolution. In particular, I discuss how: ▪The strongest star–planet connection is still the giant planet–metallicity correlation, the strength of which may indicate a break point between the formation of planets versus brown dwarfs.▪We do not have very good constraints on the lower metallicity limit for planet formation, although new statistics from TESS are helping, and it appears that, at low [Fe/H], α elements can substitute for iron as seeds for planet formation.▪The depletion of refractory versus volatile elements in stellar photospheres (particularly the Sun) was initially suggested as a sign of small planet formation but is challenging to interpret, and small differences in binary star compositions can be attributed mostly to processes other than planet formation.▪We can and should go beyond comparisons of the carbon-to-oxygen ratio in giant planets and their host stars, incorporating other volatile and refractory species to better constrain planet formation pathways.▪There appears to be a positive correlation between small planet bulk density and host star metallicity, but exactly how closely small planet refractory compositions match those of their host stars—and their true diversity—is still uncertain.

中文翻译：

---

星-行星组成联系


事实证明，“了解你的星星，了解你的星球”这句口号已被证明对系外行星科学的许多方面都非常重要。在这里，我回顾了恒星丰度如何影响我们对行星组成的理解，从而影响我们对行星形成和演化的理解。特别是，我讨论了如何：▪最强的恒星-行星联系仍然是巨大的行星-金属丰度相关性，其强度可能表明行星形成与褐矮星之间的断点.▪我们对行星形成的金属丰度下限没有很好的限制，尽管来自 TESS 的新统计数据有所帮助，看起来， 在低 [Fe/H] 下，α元素可以替代铁作为行星形成的种子。▪恒星光球层（尤其是太阳）中难降解元素与挥发性元素的消耗最初被认为是小行星形成的标志，但很难解释，双星组成的微小差异主要归因于行星形成以外的过程。▪我们可以而且应该超越对巨行星及其宿主的碳氧比的比较▪小行星的体积密度和宿主恒星的金属丰度之间似乎存在正相关关系，但小行星耐火物质成分与其宿主恒星的成分以及它们的真实多样性究竟有多紧密，仍然不确定。