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arXiv 0910.3839astro-ph.EP
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OGLE-06-109L系统中行星的动力学和偏心率的形成

Dynamics and Eccentricity Formation of Planets in OGLE-06-109L System

Su Wang, Gang Zhao, Ji-Lin Zhou

摘要:

最近的微透镜技术观测揭示了OGLE-06- 109 L周围有两颗2.3 AU和4.6 AU的巨行星。外行星的离心率(ec)估计为0.11(+0.17,-0.04),与土星的离心率(0.01-0.09)相当。OGLE-06- 109 L系统和太阳系之间的相似性表明,它们在形成阶段可能经历了类似的历史。本文研究了OGLE-06- 109 L系统轨道结构的动力学和形成。对于目前这两颗行星的名义位置,只要它们的偏心率(eb; ec)满足eb^2 + ec^2 < = 0.3^2,长期运动就是稳定的。地球大小的天体可能形成并稳定在系统的宜居带(0.25 AU-0.36 AU)。eb和ec的形成有三种可能的情况:(i)两颗行星的会聚迁移和3:1 MMR捕获;(ii)行星散射;(iii)发散迁移和3:1 MMR交叉。正如我们所展示的,在3:1 MMR中存在两颗巨行星的概率很低(~3%),场景(i)的可能性较小。根据模型(ii)和(iii),内行星(eb)的最终偏心率可能在[0-0.06]之间振荡,与木星的偏心率(0.03-0.06)相当。对eb、ec长期运动的考察可能有助于理解哪种模型是造成偏心的真正原因。

英文摘要:

Recent observation of microlensing technique reveals two giant planets at 2.3 AU and 4.6 AU around the star OGLE-06-109L. The eccentricity of the outer planet (ec) is estimated to be 0.11(+0.17,-0.04), comparable to that of Saturn (0.01-0.09). The similarities between the OGLE-06-109L system and the solar system indicate that they may have passed through similar histories during their formation stage. In this paper we investigate the dynamics and formation of the orbital architecture in the OGLE-06-109L system. For the present two planets with their nominal locations, the secular motions are stable as long as their eccentricities (eb; ec) fulfill eb^2 + ec^2 < = 0.3^2. Earth-size bodies might be formed and are stable in the habitable zone (0.25AU-0.36AU) of the system. Three possible scenarios may be accounted for formation of eb and ec: (i) convergent migration of two planets and the 3:1 MMR trapping; (ii) planetary scattering; (iii) divergent migration and the 3:1 MMR crossing. As we showed that the probability for the two giant planets in 3:1 MMR is low (~3%), scenario (i) is less likely. According to models (ii) and (iii), the final eccentricity of inner planet (eb) may oscillate between [0-0.06], comparable to that of Jupiter (0.03-0.06). An inspection of eb, ec secular motion may be helpful to understand which model is really responsible for the eccentricity formation.

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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