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.

临边暗化，即可见星盘径向亮度的变化，是恒星和行星系统研究领域的重要物理参数。不幸的是，只有太阳才能直接测量临边变暗，而恒星的临边变暗通常是从大气模型中推断出来的。由于在类太阳恒星周围发现了许多行星，特别是通过凌日法，临边变暗的研究经历了某种复兴。临边变暗确实与大多数其他凌日参数表现出很强的相关性，因此大多数系外行星观测者将恒星临边变暗视为凌日模型中的“麻烦”参数。然而，如果数据质量足够，则可以在行星食期间直接测量临边变暗。足够高。此外，不太为人所知的是，临边变暗对于透射光谱学领域以及因此对于所有系外行星大气及其化学成分的研究也非常重要。因此，现在是时候重新审视恒星边缘变暗，特别关注其对使用凌日法研究太阳系外行星的影响，这是这里提出的研究项目的中心主题。我们特别建议使用最新的恒星模型大气尽可能真实地进行凌日光曲线模拟，并开发分析方法，以尽可能独立于临边变暗的方式推导凌日参数。这些分析方法将应用于现有的档案数据，同时，我们计划研究 JWST 在太阳系外行星凌日研究中的潜力。另一个主要问题是差分边缘变暗问题，充分了解这一问题对于在高分辨率透射光谱中解开行星和恒星信号至关重要，旨在揭示系外行星大气的光谱特征。为了完成我们的研究项目，我们计划研究快速旋转对主恒星和行星扁率的影响。