On the abundance of circumbinary planets
On the abundance of circumbinary planets
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DOI：
10.1093/mnras/stu1570
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发表时间：
2014-10-21
影响因子：
4.8
通讯作者：
Udry, S.
中科院分区：
文献类型：
--
作者：
Armstrong, D. J.;Osborn, H. P.;Udry, S.
在这里，我们提出了第一个基于观测的外周双星出现速度的测定。这是从可公开获得的开普勒数据中得出的，使用自动搜索算法和去偏置过程来产生已知的七个系统所隐含的出现率。这些速率严重取决于行星倾角分布：如果如所建议的那样，外接双星行星优先与其宿主双星共面，则具有R-p>；6R(圆加)的行星绕P-p<；300d轨道运行的行星的出现率为10.0(-6.5)(+18)%(95%的置信限)，高于但与单星速率一致。另一方面，如果潜在的行星倾角分布是各向同性的，那么这种发生率就会急剧上升，给出47%的下限。这意味着，在环行双星盘中的形成和随后的动力学演化必须要么导致大体上共面的行星，要么比在星周盘中进行得更容易。作为这项研究的结果，我们还表明，巨行星(>；10R(圆加))在环行双星轨道上的罕见程度明显低于它们较小的兄弟行星，并证实了开普勒样本中围绕较短周期双星轨道运行的环行双星数量的不足是真实的影响。
We present here the first observationally based determination of the rate of occurrence of circumbinary planets. This is derived from the publicly available Kepler data, using an automated search algorithm and debiasing process to produce occurrence rates implied by the seven systems already known. These rates depend critically on the planetary inclination distribution: if circumbinary planets are preferentially coplanar with their host binaries, as has been suggested, then the rate of occurrence of planets with R-p > 6R(circle plus) orbiting with P-p < 300 d is 10.0(-6.5)(+18) per cent (95 per cent confidence limits), higher than but consistent with single star rates. If on the other hand the underlying planetary inclination distribution is isotropic, then this occurrence rate rises dramatically, to give a lower limit of 47 per cent. This implies that formation and subsequent dynamical evolution in circumbinary discs must either lead to largely coplanar planets, or proceed with significantly greater ease than in circumstellar discs. As a result of this investigation, we also show that giant planets (> 10R(circle plus)) are significantly less common in circumbinary orbits than their smaller siblings, and confirm that the proposed shortfall of circumbinary planets orbiting the shorter period binaries in the Kepler sample is a real effect.