The evolutionary tale of gaseous exoplanets: a brief history of time - exoplanet edition

Abstract

This thesis investigates the evolution and fate of gaseous exoplanets, which are continuously shaped by stellar activity across both short and long timescales. Short-term events, such as stellar flares, produce intense bursts of high-energy radiation that break apart molecules in the upper atmosphere of the exoplanet, driving significant chemical changes. Over longer periods, prolonged exposure to strong stellar irradiation gradually heats the planet, leading to atmospheric escape and potential transformation in its structure and composition. To better understand these processes, we employ chemical disequilibrium modelling, radiative transfer simulations, and planetary evolution codes to analyse the interiors and atmospheres of gaseous exoplanets. By doing so, we aim to determine how these external influences shape their composition, structure, and observable characteristics, shedding light on their long-term atmospheric evolution.