Exoplanet discoveries have reached into the realm of terrestrial planets that are becoming the subject of atmospheric studies. One such discovery is LHS 3844b, a 1.3 Earth radius planet in a 0.46 day orbit around an M4.5-5 dwarf star. Follow-up observations indicate that the planet is largely devoid of substantial atmosphere. This lack of significant atmosphere places astrophysical and geophysical constraints on LHS 3844b, primarily the degree of volatile outgassing and the rate of atmosphere erosion. We estimate the age of the host star as 7.8 ± 1.6 Gyr and find evidence of an active past comparable to that of Proxima Centauri. We use geodynamical models of volcanic outgassing and atmospheric erosion to show that the apparent lack of atmosphere is consistent with a volatile-poor mantle for LHS 3844b. We show the core is unlikely to host enough C to produce a sufficiently volatile-poor mantle, unless the bulk planet is volatile-poor relative to Earth. While we cannot rule out a ...

中文翻译：

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基于缺乏明显大气的LHS 3844b的挥发性较差的形成

系外行星的发现已经进入了成为大气研究主题的地球行星的领域。这样的发现之一就是LHS 3844b，它是一颗绕地心半径为1.3的行星，位于M4.5-5矮星周围0.46天的轨道上。后续观察表明，该星球基本上没有大气层。缺乏明显的大气层对LHS 3844b造成了天体物理和地球物理方面的限制，主要是挥发气体的释放程度和大气层侵蚀的速率。我们估计寄主恒星的年龄为7.8±1.6 Gyr，并发现了与Proxima Centauri相当的活跃过去的证据。我们使用火山脱气和大气侵蚀的地球动力学模型来表明，大气的明显缺乏与LHS 3844b的挥发性差的地幔一致。我们表明，除非大行星相对于地球而言是挥发性较差的，否则核心不太可能承载足够的C来产生足够易挥发的地幔。虽然我们不能排除...