Systematic analysis of stellar transit light curves for the characterization of short-period extrasolar planets

系统分析恒星凌日光变曲线以表征短周期系外行星

• 批准号: 362584047
• 负责人: Privatdozent Dr. Martin Pätzold
• 金额: --
• 依托单位: Rheinisches Institut für Umweltforschung (EURAD)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/362584047?language=en
• 关键词: Systematic; analysis; stellar; transit; light

More than 3500 extrasolar planets were discovered to date. The study of a large ensemble of planetary systems of different kind may allow to conclude on the formation and evolution of planetary systems and the associated physical processes. The transit method is the most successful method for the discovery of exoplanets. Space telescopes like CoRoT, Kepler and K2 observed a large number of stars simultaneously and continuously. The orbital period; the planetary radius and the planetary semi major axis relative to the radius of the star, the inclination and eccentricity of the planetary orbit are determined from the transit by fitting analytic light curve models. The planetary mass is determined from a combination of transit and ground-based radial velocity measurements (RV) or in some cases by transit time variation (TTV). Other physical properties of planetary systems were occasionally discovered in light curves (e.g. light reflected by planets, ellipsoid variation, differential rotation of the star, angle between the stellar rotation axis and the planetary orbit, eccentricity of planetary orbits). Only crude estimates exist for other properties (e.g., apsidal precession, moons, rings, and trojans). This project shall systematically examine all existing light curves with planetary transits from the Kepler, CoRoT and K2 missions for known and/or theoretically predicted variations before, during and after the transit. The large ensemble of light curves may also build the foundation for a statistical analysis which shall characterize previously unexplained variations in the light curves which may then describe the associated physical phenomena.We want to apply our extensive experience gained from the analysis of stellar light curves and planetary transits made on the space missions CoRoT, Kepler and K2. The data already processed with our detection pipeline shall be exploited in more detail. A new numerical light curve model shall be developed. This numerical model shall be able to simulate light curve phenomena not considered in the commonly used Mandel-Agol model. The model shall give estimates if certain phenomena are detectable in the light curves with today's technique and which kind of stars may be suitable for observation (period, spectral type of star, etc.). The model shall help to clarify the physical reason of unknown phenomena. The systematic investigation of the light curves should increase the information and the number of parameters obtained directly from the light curve. In addition, the information shall be used to identify false positives.

迄今为止，已经发现了3500多颗太阳系外行星。对不同类型的行星系统的大集合的研究可以使我们对行星系统的形成和演化以及相关的物理过程得出结论。凌日法是发现系外行星最成功的方法。CoRoT、Kepler和K2等太空望远镜同时连续观察了大量恒星。轨道周期;通过拟合解析光变曲线模型，由凌日确定行星半径、行星半长轴相对于星星半径的关系、行星轨道倾角和偏心率。行星的质量由凌日和地面径向速度测量（RV）的组合确定，在某些情况下由凌日时间变化（TTV）确定。行星系统的其他物理性质偶尔也会在光变曲线中发现（例如行星反射的光、椭球变化、星星的差速自转、恒星自转轴与行星轨道之间的夹角、行星轨道的偏心率）。其他属性仅存在粗略估计（例如，拱点岁差、卫星、环和特洛伊）。该项目将系统地检查开普勒、CoRoT和K2飞行任务中行星凌日的所有现有光变曲线，以了解凌日之前、期间和之后的已知和/或理论上预测的变化。光变曲线的大集合也可能为统计分析奠定基础，统计分析将描述光变曲线中以前无法解释的变化，然后描述相关的物理现象。我们希望应用我们在CoRoT，Kepler和K2空间任务中对恒星光变曲线和行星凌日分析中获得的丰富经验。我们的检测管道已经处理的数据将被更详细地利用。应开发新的数值光变曲线模型。该数值模型应能够模拟常用Mandel-Agol模型中未考虑的光变曲线现象。 该模型应估计某些现象是否可以用当今的技术在光变曲线中检测到，以及哪种恒星可能适合观测（周期、星星的光谱类型等）。该模型将有助于澄清未知现象的物理原因。光变曲线的系统研究应增加直接从光变曲线获得的信息和参数的数量。此外，该信息还应用于识别误报。