发表机构
Kapteyn Astronomical Institute, University of Groningen; Institute of Astronomy, University of Cambridge; Department of Earth and Planetary Sciences, ETH Zurich（格罗宁根大学卡普坦天文研究所; 剑桥大学天文学研究所; 苏黎世联邦理工学院地球与行星科学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过PROTEUS框架耦合模型发现，贫挥发性超级地球结晶时内部收缩约10%，而富挥发性大质量超级地球因厚大气层抑制散热可能不固化，为解释低质量系外行星观测提供新视角。
AI 中文摘要
超级地球系外行星是已知最丰富的行星之一，然而其体密度使得内部状态存在简并性。用于解释这些行星的静态结构模型以及基于这些模型构建的内部反演，通常描述的是从炽热熔融状态开始演化后的冷、固化终态。在岩浆洋阶段，内部、脱气大气层和表面共同演化，并决定了超级地球的长期气候和地球物理特性。我们在PROTEUS框架内开发并验证了一个用于超级地球系外行星结构和热演化的完全耦合模型，包括新的和升级的内部结构、地幔能量学和挥发性气体脱气模型。在质量为1至10个地球质量的贫挥发性超级地球中，硅酸盐内部通过冷却和结晶收缩约其熔融半径的10%，这一收缩几乎与行星质量无关，仅由硅酸盐壳层的变薄驱动。固化半径由行星质量和核占比决定，对宿主恒星、辐照和初始热状态不敏感。相比之下，质量约5个地球质量及以上的富挥发性超级地球可能不会固化：其厚实的脱气大气层抑制了表面热损失，直到内部稳定在深层岩浆洋状态，使行星保持膨胀状态，并将收缩限制在贫挥发性行星收缩值的一半左右。因此，仅地幔收缩就塑造了低质量系外行星的凌星种群，这促使在即将进行的系外行星巡天中对大气和地球物理特征进行联合解释。
英文摘要
Super-Earth exoplanets are among the most abundant planets known, yet their bulk densities leave the interior state degenerate. The static structure models used to interpret them, and the interior retrievals built on them, typically describe the cold, solidified end state of an evolution that begins hot and molten. During this magma ocean stage the interior, the outgassed atmosphere, and the surface co-evolve and set the long-term climate and geophysics of super-Earths. We develop and validate a fully coupled model for the structural and thermal evolution of super-Earth exoplanets within the PROTEUS framework, including new and upgraded models of the interior structure, mantle energetics, and volatile outgassing. In volatile-poor super-Earths of 1 to 10 Earth masses, the silicate interior contracts by about 10 % of its molten radius through cooling and crystallisation, nearly independent of planet mass and driven by the thinning silicate shell alone. The solidified radius is set by planetary mass and core fraction, insensitive to the host star, irradiation, and initial thermal state. In contrast, volatile-rich super-Earths at and above about 5 Earth masses may not solidify: their thick outgassed atmospheres throttle the surface heat loss until the interior settles into a deep magma ocean, keeping the planet inflated and limiting the contraction to about half its volatile-poor value. Mantle contraction alone thus shapes the low-mass exoplanet transit population, motivating joint interpretation of atmospheric and geophysical signatures in upcoming exoplanet surveys.
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