Exploring the effects of limb darkening on multi-wavelength photometric and spectroscopic studies of extrasolar planets

探索临边变暗对太阳系外行星多波长光度和光谱研究的影响

基本信息

批准号：
402218555
负责人：
Professor Dr. Jürgen H.M.M. Schmitt
金额：
--
依托单位：
Hamburger Sternwarte
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/402218555?language=en
关键词：
Exploring effects limb darkening multi

项目摘要

Limb darkening, i.e., the brightness change on the visible stellar disk in radial direction, is an important physical parameter in the research area of stellar and planetary systems. Unfortunately, a direct measurement of limb darkening is only possible for the Sun, while limb darkening for stars is usually inferred from atmosphere models. Due to the discovery of many planets around solar-like stars especially with the transit method, the study of the limb darkening has undergone some kind of renaissance. Limb darkening does show strong correlations with most other transit parameters, therefore most exoplanet observers treat stellar limb darkening as a ``nuisance'' parameter in their transit modeling.However, limb darkening can directly be measured during a planetary eclipse, if the data quality is sufficiently high. Furthermore and less well known, limb darkening is also very important for the area of transmission spectroscopy and consequently for all studies of the exoplanetary atmospheres and their chemical composition. The time has therefore come to take a fresh look at stellar limb darkening with a specific focus on its influence on the study of extrasolar planets using the transit method, which is the central theme of the here proposed research project. We specifically propose to carry out transit light curve simulations as realistically as possible using most recent stellar model atmospheres and develop analysis methods that allow to derive the transit parameters in a fashion as independently from limb darkening as possible. These analysis methods shall be applied to existing archival data, and at the same time, we plan to study the potential of JWST for transit studies of extrasolar planets. A further major issue is that of differential limb darkening, a good knowledge of which is absolutely essential to disentangle planetary and stellar signals in high resolution transmission spectroscopy aimed at revealing spectroscopic signatures of exoplanetary atmospheres. To complete our research project we plan to investigate the influence of oblateness of both the host star and the planet caused by fast rotation.

肢体变暗，即，径向上可见的恒星磁盘上的亮度变化是恒星和行星系统研究领域的重要物理参数。不幸的是，只有太阳可以直接测量肢体变暗，而恒星的肢体变暗通常是从大气模型中推断出来的。由于在太阳能恒星周围发现了许多行星，尤其是使用过境方法，因此对肢体变黑的研究已经发生了某种文艺复兴时期。肢体变暗确实与大多数其他过境参数显示出很强的相关性，因此，大多数系外行星观察者将恒星的四肢变暗视为其运输建模中的``nuisance''参数。此外，鲜为人知的是，肢体变黑对于传输光谱区域也非常重要，因此对于所有对超球星境及其化学组成的研究也非常重要。因此，现在是时候仔细研究了恒星四肢变黑，具体的重点是使用Transit方法的影响，这是此处建议的研究项目的中心主题。我们专门建议使用最新的恒星模型大气并开发分析方法，并尽可能地进行过境光曲线模拟，并开发出以一种独立于肢体变暗的方式得出过境参数的分析方法。这些分析方法应应用于现有的档案数据，同时，我们计划研究JWST对极性行星过境研究的潜力。另一个主要问题是差异肢体变黑，这对于在高分辨率传播光谱中脱离行星和恒星信号绝对必要的知识是至关重要的，该光谱旨在揭示超级行星大气的光谱特征。为了完成我们的研究项目，我们计划调查宿主星的污垢的影响和由快速旋转引起的行星的影响。