Stellar activity and its effects on planetary transits

Abstract

Since the discovery of the first Exoplanets (planets outside the Solar System) in the 90s, and the first detection of a planetary transit in the year 2000, the transit method of detecting a planet has been used by several space telescopes, such as Kepler and TESS. These discoveries contributed crucially to the study and characterization of exoplanets and to the search for planets with habitable conditions (existence of liquid water on their surface), such as Earth. Through modelling the light curve of an exoplanet host star, some planetary parameters can be determined, such as the radius, inclination angle, and semi-major axis of the orbit. However, a host star may have spots on its surface which can cause small variations in the light curve when the planet passes in front of one of these spots. Variations in the transit light curves make the parameters less accurate and even underestimated. Therefore due to variations caused by stellar activity, it is necessary to model stellar spots to better estimate the characteristics of the extrasolar planets. In this project, we will develop a pipeline of Python programs for calibrating, analyzing, and modeling variations in transit light curves due to spots to improve the accuracy of planetary and orbital parameters and their relationship to stellar activity. (AU)