DETECTING THE WIND-DRIVEN SHAPES OF EXTRASOLAR GIANT PLANETS FROM TRANSIT PHOTOMETRY
DETECTING THE WIND-DRIVEN SHAPES OF EXTRASOLAR GIANT PLANETS FROM TRANSIT PHOTOMETRY
复制标题
通过凌日光度测量检测太阳系外巨行星的风驱动形状
DOI：
10.1088/0004-637x/706/1/877
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
W. Hubbard
中科院分区：
文献类型：
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作者：
J. Barnes;C. Cooper;A. Showman;W. Hubbard
有几个过程可以导致太阳系外巨行星的阴影形状，如在过境时所看到的，偏离圆形。除了旋转效应之外，云的形成、非均匀的霾的产生和移动以及动力效应（风）也可能很重要。从地球上看，当这样一颗行星凌日它的主星星星时，非球面性将使凌日光变曲线相对于完美球形（或完美扁圆）行星的凌日产生偏差。我们开发了一个理论框架来解释行星的形状。然后，我们根据已发表的HD189733b理论动力学模型生成过境行星形状的预测。利用这些形状模型，我们发现行星的形状不太可能引入可检测的光变曲线偏差（大于主星星的1 × 10−5），但在测量行星扁率、渡越时间和撞击参数时，这些形状可能会导致天体物理学上的系统误差。
Several processes can cause the shape of an extrasolar giant planet's shadow, as viewed in transit, to depart from circular. In addition to rotational effects, cloud formation, non-homogenous haze production and movement, and dynamical effects (winds) could also be important. When such a planet transits its host star as seen from the Earth, the asphericity will introduce a deviation in the transit light curve relative to the transit of a perfectly spherical (or perfectly oblate) planet. We develop a theoretical framework to interpret planetary shapes. We then generate predictions for transiting planet shapes based on a published theoretical dynamical model of HD189733b. Using these shape models we show that planet shapes are unlikely to introduce detectable light-curve deviations (those >1 × 10−5 of the host star), but that the shapes may lead to astrophysical sources of systematic error when measuring planetary oblateness, transit time, and impact parameter.