论文标题
托管潜在可居住的系外行星的系外行星系统的潮汐进化。 LHS-1140 B-C和K2-18 B-C的病例
Tidal evolution of exoplanetary systems hosting Potentially Habitable Exoplanets. The cases of LHS-1140 b-c and K2-18 b-c
论文作者
论文摘要
我们提出了一个模型，用于研究由两个低质量行星组成的世俗和潮汐发展的三体系统，在旋转恒星的情况下，在身体旋转轴始终垂直于轨道平面的情况下。潮汐理论使我们能够研究僵硬的地球行星和主要是气态海王星样行星的自旋和轨道演化。该模型应用于研究两个最近发现的外球星系，其中包含潜在的可居住系外行星（PHE）：LHS-1140 B-C和K2-18 B-C。对于以前的系统，我们表明两个LHS-1140 B和C都必须在几乎圆形轨道上。对于K2-18 B-C，对轨道进化时间尺度的组合分析具有当前的K2-18 B偏心率估计，这使我们得出结论，内行星（K2-18 C）必须是海王星样的气态体。只有这将允许K2-18 B的偏心率在最近的工作中估计的值（$ e = 0.20 \ pm 0.08 $），前提是，K2-18 B的均匀粘度系数大于$ 2.4 \ $ 2.4 \ times 10^{19}} {19}}}}}} \ \ \ \ \ \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\米米
We present a model to study secularly and tidally evolving three-body systems composed by two low-mass planets orbiting a star, in the case where the bodies rotation axes are always perpendicular to the orbital plane. The tidal theory allows us to study the spin and orbit evolution of both stiff Earth-like planets and predominantly gaseous Neptune-like planets. The model is applied to study two recently-discovered exoplanetary systems containing potentially habitable exoplanets (PHE): LHS-1140 b-c and K2-18 b-c. For the former system, we show that both LHS-1140 b and c must be in nearly-circular orbits. For K2-18 b-c, the combined analysis of orbital evolution timescales with the current eccentricity estimation of K2-18 b allows us to conclude that the inner planet (K2-18 c) must be a Neptune-like gaseous body. Only this would allow for the eccentricity of K2-18 b to be in the range of values estimated in recent works ($e=0.20 \pm 0.08$), provided that the uniform viscosity coefficient of K2-18 b is greater than $2.4 \times 10^{19} \ \textrm{Pa s}$ (which is a value characteristic of stiff bodies) and supposing that such system has an age of some Gyr.
