Binarity of transit host stars - Implications for planetary parameters
Binarity of transit host stars - Implications for planetary parameters
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凌日主星的二元性——对行星参数的影响
DOI：
10.1051/0004-6361/200810988
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发表时间：
2009
影响因子：
6.5
通讯作者：
T. Henning
中科院分区：
文献类型：
--
作者：
S. Daemgen;F. Hormuth;W. Brandner;C. Bergfors;M. Janson;M. Janson;S. Hippler;T. Henning
上下文行星参数的直接推导只能在凌日行星系统中实现。然而，行星的属性，如半径和质量强烈依赖于恒星的主机参数。发现凌日主星星是多个导致导出的恒星和行星参数的必要修订。目标。基于我们对14个凌日系外行星宿主的观测，我们推导出了三个凌日宿主星（WASP-2，TrES-2和TrES-4）的各个组成部分的参数，我们检测到它们是双星。其中两个以前不知道是多重的。修正了相应系外行星的参数。方法.高分辨率的“幸运成像”与AstraLux在2.2米的卡拉阿尔托望远镜提供了近衍射极限的图像在i'和z'通带。这些结果与现有的行星数据相结合，以重新校准行星属性。结果尽管发现的TrES-2、TrES-4和WASP-2的伴星亮度较暗（Δ mag ~ 4），但光变曲线推导的参数变化可达1 σ以上。我们讨论了双星分离和行星性质之间的可能关系，如果得到证实，可能暗示双星对行星形成过程的影响。
Context. Straight-forward derivation of planetary parameters can only be achieved in transiting planetary systems. However, planetary attributes such as radius and mass strongly depend on stellar host parameters. Discovering a transit host star to be multiple leads to a necessary revision of the derived stellar and planetary parameters. Aims. Based on our observations of 14 transiting exoplanet hosts, we derive parameters of the individual components of three transit host stars (WASP-2, TrES-2, and TrES-4) which we detected to be binaries. Two of these have not been known to be multiple before. Parameters of the corresponding exoplanets are revised. Methods. High-resolution “Lucky Imaging” with AstraLux at the 2.2 m Calar Alto telescope provided near diffraction limited images in i' and z' passbands. These results have been combined with existing planetary data in order to recalibrate planetary attributes. Results. Despite the faintness ( Δ mag ~ 4) of the discovered stellar companions to TrES-2, TrES-4, and WASP-2, light-curve deduced parameters change by up to more than 1 σ . We discuss a possible relation between binary separation and planetary properties, which – if confirmed – could hint at the influence of binarity on the planet formation process.