Predicted diversity in water content of terrestrial exoplanets orbiting M dwarfs
Predicted diversity in water content of terrestrial exoplanets orbiting M dwarfs
复制标题
绕 M 矮星运行的类地系外行星的水含量多样性预测
DOI：
10.1038/s41550-022-01781-1
复制
发表时间：
2022
期刊：
影响因子：
14.1
通讯作者：
Ikoma Masahiro
中科院分区：
文献类型：
--
作者：
Kimura Tadahiro;Ikoma Masahiro
围绕M矮星的系外行星调查发现了越来越多的具有类似地球日射的系外行星。预计其中一些行星是岩石行星，有可能存在有利于地表液态水的温和气候。然而，各种模型预测，在M矮星周围的经典可居住带中运行的类地行星没有水或太多水，这表明M矮星周围的可居住行星可能很罕见。在这里，我们提出了一个更新的行星人口合成模型的结果，其中包括水富集在原始大气中的影响，所造成的大气氢氧化的岩石材料从传入的星子和岩浆海洋。我们发现，这种原始大气中的水生产被发现显着影响陆地岩石水行星的出现，产生不同的水含量。我们估计，5-10%的大小小于1.3R的行星绕着早期到中期的M矮星运行，有适量的海水可供居住。这样的发生率将足以通过正在进行的和不久的将来的M-矮行星调查任务来检测潜在的宜居行星。
Exoplanet surveys around M dwarfs have detected a growing number of exoplanets with Earth-like insolation. It is expected that some of those planets are rocky planets with the potential for temperate climates favourable to surface liquid water. However, various models predict that terrestrial planets orbiting in the classical habitable zone around M dwarfs have no water or too much water, suggesting that habitable planets around M dwarfs might be rare. Here we present the results of an updated planetary population synthesis model, which includes the effects of water enrichment in the primordial atmosphere, caused by the oxidation of atmospheric hydrogen by rocky materials from incoming planetesimals and from the magma ocean. We find that this water production in the primordial atmosphere is found to significantly impact the occurrence of terrestrial rocky aqua planets, yielding ones with diverse water content. We estimate that 5–10% of the planets with a size of <1.3R⊕orbiting early-to-mid M dwarfs have appropriate amounts of seawater for habitability. Such an occurrence rate would be high enough to detect potentially habitable planets by ongoing and near-future M-dwarf planet survey missions.