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arXiv 0801.3226astro-ph
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太阳系外行星相互作用

Extrasolar Planet Interactions

Rory Barnes, Richard Greenberg

摘要:

行星系统的动力学相互作用可能是它们形成历史的线索。因此,这些相互作用的分布对行星形成的模型提供了重要的限制。我们专注于每个系统的拱点运动和接近动力学不稳定。虽然迄今为止只发现了约25个多行星系统,但我们在这些方面的分析揭示了行星相互作用的几个重要特征。1)许多系统相互作用,使得它们接近稳定性和不稳定性之间的边界。2)行星的形成倾向于至少有一颗行星的偏心率周期性地下降到接近零。3)如果没有共振,平均运动共振对将是不稳定的。4)质量近似相等的行星的散射不太可能产生所观察到的拱点行为分布。5)共振相互作用可以通过计算系统接近不稳定性来识别,而不考虑角度的知识,如平均经度和近星点经度(例如GJ 317 b和c可能处于4:1共振)。行星系统的这些性质是通过计算描述相互作用的两个参数来确定的。拱点相互作用可以通过确定行星与拱点分界线(性质不同类型的拱点振荡之间的边界,例如长轴的天平动或环流)的距离来量化。不稳定性的接近程度可以通过将观测到的轨道要素与描述一种称为希尔稳定性的稳定性的分析边界进行比较来测量。我们已经建立了一个网站,致力于提供动态交互的最新信息:http://www.lpl.arizona.edu/~rory/research/xsp/dynamics

英文摘要:

The dynamical interactions of planetary systems may be a clue to their formation histories. Therefore, the distribution of these interactions provides important constraints on models of planet formation. We focus on each system's apsidal motion and proximity to dynamical instability. Although only ~25 multiple planet systems have been discovered to date, our analyses in these terms have revealed several important features of planetary interactions. 1) Many systems interact such that they are near the boundary between stability and instability. 2) Planets tend to form such that at least one planet's eccentricity periodically drops to near zero. 3) Mean-motion resonant pairs would be unstable if not for the resonance. 4) Scattering of approximately equal mass planets is unlikely to produce the observed distribution of apsidal behavior. 5) Resonant interactions may be identified through calculating a system's proximity to instability, regardless of knowledge of angles such as mean longitude and longitude of periastron (e.g. GJ 317 b and c are probably in a 4:1 resonance). These properties of planetary systems have been identified through calculation of two parameters that describe the interaction. The apsidal interaction can be quantified by determining how close a planet is to an apsidal separatrix (a boundary between qualitatively different types of apsidal oscillations, e.g. libration or circulation of the major axes). The proximity to instability can be measured by comparing the observed orbital elements to an analytic boundary that describes a type of stability known as Hill stability. We have set up a website dedicated to presenting the most up-to-date information on dynamical interactions: http://www.lpl.arizona.edu/~rory/research/xsp/dynamics

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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