CORELESS TERRESTRIAL EXOPLANETS
CORELESS TERRESTRIAL EXOPLANETS
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DOI：
10.1086/592316
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发表时间：
2008-11-20
影响因子：
4.9
通讯作者：
Seager, Sara
中科院分区：
文献类型：
--
作者：
Elkins-Tanton, Linda T.;Seager, Sara
类地行星的分化预计包括金属铁核的形成。我们预测存在已经分化但没有金属核心的类地行星，这些行星实际上是一个巨大的硅酸盐地幔。我们讨论了两种形成无核类地行星的途径，即行星吸积和凝固过程中的氧化状态将决定任何金属核的大小或存在。根据这一假设，块状吸积物质中的任何金属铁都会被水氧化，以氧化铁的形式将铁结合到行星地幔的硅酸盐矿物中。这种硅酸盐行星的存在对根据质量和半径测量来解释系外行星的组成和内部密度结构具有重要意义。
Differentiation in terrestrial planets is expected to include the formation of a metallic iron core. We predict the existence of terrestrial planets that have differentiated but have no metallic core, planets that are effectively a giant silicate mantle. We discuss two paths to forming a coreless terrestrial planet, whereby the oxidation state during planetary accretion and solidification will determine the size or existence of any metallic core. Under this hypothesis, any metallic iron in the bulk accreting material is oxidized by water, binding the iron in the form of iron oxide into the silicate minerals of the planetary mantle. The existence of such silicate planets has consequences for interpreting the compositions and interior density structures of exoplanets based on their mass and radius measurements.