Detection of an Atmosphere on a Rocky Exoplanet
Detection of an Atmosphere on a Rocky Exoplanet
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DOI：
10.3847/1538-3881/abe879
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
M. Swain;R. Estrela;G. Roudier;C. Sotin;P. Rimmer;A. Valio;R. West;K. Pearson;Noah Huber-Feely;R. Zellem
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作者：
M. Swain;R. Estrela;G. Roudier;C. Sotin;P. Rimmer;A. Valio;R. West;K. Pearson;Noah Huber-Feely;R. Zellem
我们报告了在一颗岩石系外行星GJ1132b上探测到的大气，这颗行星在大小和密度上与地球相似。利用哈勃WFC3测量探测到了大气透射谱，并显示了低平均分子质量大气中气溶胶散射、HCN和CH4的光谱特征。我们模拟了大气损失过程，并得出结论，GJ1132b可能失去了原始的H/He包络，这表明我们探测到的大气已经重新建立。我们探索了氢地幔脱气的可能性，之前通过理论研究确定了这颗行星的可能性，并发现超还原岩浆的放气可以产生观测到的大气。通过这种方式，我们使用观测到的系外行星传输光谱来洞察一颗类地行星的岩浆成分。探测到这颗岩石行星上的大气，增加了这样一种可能性，即在有利的情况下，被认为是海王星以下蒸发核心的众多超级地球行星可能拥有可探测到的大气。
We report the detection of an atmosphere on a rocky exoplanet, GJ 1132 b, which is similar to Earth in terms of size and density. The atmospheric transmission spectrum was detected using Hubble WFC3 measurements and shows spectral signatures of aerosol scattering, HCN, and CH4 in a low mean molecular weight atmosphere. We model the atmospheric loss process and conclude that GJ 1132 b likely lost the original H/He envelope, suggesting that the atmosphere that we detect has been reestablished. We explore the possibility of H2 mantle degassing, previously identified as a possibility for this planet by theoretical studies, and find that outgassing from ultra-reduced magma could produce the observed atmosphere. In this way we use the observed exoplanet transmission spectrum to gain insights into magma composition for a terrestrial planet. The detection of an atmosphere on this rocky planet raises the possibility that the numerous powerfully irradiated super-Earth planets, believed to be the evaporated cores of sub-Neptunes, may, under favorable circumstances, host detectable atmospheres.