论文标题
Planetary System LHS 1140与浓缩咖啡和苔丝重新审视
Planetary system LHS 1140 revisited with ESPRESSO and TESS
论文作者
论文摘要
LHS 1140是一个已知的M矮人，在轨道期为3.77和24.7天，可以容纳两个已知的过渡行星。外部行星（LHS 1140 b）是位于该低质量恒星宜居区中间的岩石超级地球，将该系统置于可居住的系外行星探索的最前沿。我们通过改善物理和轨道特性并在系统中寻找其他行星质量组件来进一步表征该系统，还探索了共晶的可能性。我们收集了113个新的径向速度观测值，并在1。5年的时间范围内，平均光子噪声精度为1.07 m/s。我们确定LHS 1140 B的精度为6％（$ 6.48 \ pm 0.46〜m _ {\ oplus} $），LHS 1140 C（$ M_C = 1.78 \ pm 0.17〜M _ {\ oplus} $），以前降低了一半的无效。尽管这两个行星都具有类似地球的散装组成，但内部结构分析表明LHS 1140 B可能具有富含铁。在这两种情况下，水含量均可兼容质量的最大分数为10-12％，这相当于可居住区LHS LHS 1140 b的深海层$ 779 \ pm 650 $ km。我们的结果还提供了系统中新的行星候选者的证据（$ m_d = 4.8 \ pm1.1〜m _ {\ oplus} $）在〜78.9天轨道时期，这是通过三种独立方法检测到的。该分析还允许我们丢弃其他超过0.5 $ m _ {\ oplus} $的行星，该期限短于10天及以上2 $ m _ {\ oplus} $，最多一年。最后，我们的分析将LHS 1140 B的共轨道行星丢弃至1 $ m _ {\ oplus} $。但是，在径向速度和光度数据中都检测到了LHS 1140 C中可能的共轨信号的指示。该系统的新特征使其成为对不同恒星辐照的岩石世界大气研究的关键目标
LHS 1140 is an M dwarf known to host two known transiting planets at orbital periods of 3.77 and 24.7 days. The external planet (LHS 1140 b) is a rocky super-Earth that is located in the middle of the habitable zone of this low-mass star, placing this system at the forefront of the habitable exoplanet exploration. We further characterize this system by improving the physical and orbital properties and search for additional planetary-mass components in the system, also exploring the possibility of co-orbitals. We collected 113 new radial velocity observations with ESPRESSO over a 1.5-year time span with an average photon-noise precision of 1.07 m/s. We determine new masses with a precision of 6% for LHS 1140 b ($6.48 \pm 0.46~M_{\oplus}$) and 9% for LHS 1140 c ($m_c=1.78 \pm 0.17~M_{\oplus}$), reducing by half the previously published uncertainties. Although both planets have Earth-like bulk compositions, the internal structure analysis suggests that LHS 1140 b might be iron-enriched. In both cases, the water content is compatible to a maximum fraction of 10-12% in mass, which is equivalent to a deep ocean layer of $779 \pm 650$ km for the habitable-zone planet LHS 1140 b. Our results also provide evidence for a new planet candidate in the system ($m_d= 4.8\pm1.1~M_{\oplus}$) on a ~78.9-day orbital period, which is detected through three independent methods. The analysis also allows us to discard other planets above 0.5 $M_{\oplus}$ for periods shorter than 10 days and above 2 $M_{\oplus}$ for periods up to one year. Finally, our analysis discards co-orbital planets of LHS 1140 b down to 1 $M_{\oplus}$. Indications for a possible co-orbital signal in LHS 1140 c are detected in both radial velocity and photometric data, however. The new characterization of the system make it a key target for atmospheric studies of rocky worlds at different stellar irradiations
