Obliquity and Eccentricity Constraints for Terrestrial Exoplanets
Obliquity and Eccentricity Constraints for Terrestrial Exoplanets
复制标题
类地系外行星的倾角和偏心率约束
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
S. M. Torres
中科院分区：
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作者：
S. Kane;S. M. Torres
近年来的系外行星发现表明，类地行星异常常见。这些行星中的许多都处于紧凑的系统中，导致复杂的轨道动力学。确定这些行星表面状况的关键一步是了解大气层顶部入射的纬度相关通量作为轨道相位的函数。影响通量随时间变化的两个主要性质是行星的轨道密度和轨道偏心率。我们推导出的标准，通量变化，由于双折射是等价的通量变化，由于轨道偏心率。这种等效性计算的最大和平均通量的情况下，后者包括昼夜周期的影响。我们将这些计算应用于四个已知的多行星系统（GJ 163，K2-3，开普勒-186和比邻星），在那里我们使用轨道动力学考虑约束类地行星的偏心率，并模拟入射通量的影响。我们讨论了这些模拟对类地行星气候模型的影响，并概述了可检测到的行星相似性特征。
Exoplanet discoveries over recent years have shown that terrestrial planets are exceptionally common. Many of these planets are in compact systems that result in complex orbital dynamics. A key step toward determining the surface conditions of these planets is understanding the latitudinally dependent flux incident at the top of the atmosphere as a function of orbital phase. The two main properties of a planet that influence the time-dependent nature of the flux are the obliquity and orbital eccentricity of the planet. We derive the criterion for which the flux variation due to obliquity is equivalent to the flux variation due to orbital eccentricity. This equivalence is computed for both the maximum and average flux scenarios, the latter of which includes the effects of the diurnal cycle. We apply these calculations to four known multi-planet systems (GJ 163, K2-3, Kepler-186, and Proxima Centauri), where we constrain the eccentricity of terrestrial planets using orbital dynamics considerations and model the effect of obliquity on incident flux. We discuss the implications of these simulations on climate models for terrestrial planets and outline detectable signatures of planetary obliquity.