Characterising the atmospheres of exoplanets with ground-based and JWST observations

The aim of this project is to characterise the atmospheres of exoplanets from a range of ground-based high-resolution and space-based JWST observations. This will encompass both transiting exoplanets which are close to their host star as well as more distant directly-imaged companions. The student will use the latest data reduction techniques, atmospheric modelling tools and statistical analysis methods to perform Bayesian analyses on the planetary observations, to determine the chemical composition.

This composition will be used to determine the formation conditions for these planets, and explore how the planetary system evolved to its current state. These planets are vital to understand because we have no such analogue in the Solar System, and therefore studying exoplanetary systems is the only way for us to explore the uniqueness of our Solar System.

In addition, we will analyse the temperature structures for these exoplanets, allowing us to explore how radiative processes affect the atmosphere and how these vary across the population of planets. We will also use the very high-resolution ground-based observations from facilities such as VLT (Very Large Telescope) to determine the rotation rates for these systems, which is particularly important for more distant directly-imaged companions where any differences in their orbital alignment could help us to decipher their evolutionary histories.

Finally, across our sample of exoplanets at both close-in orbits and wider separations from their star, we will compare how the planetary compositions across these populations vary. This will help us to answer the question of how and why some planets reach so close to their host while others are on very wide orbits.

In the final year of the project, we will simulate observations for exoplanetary systems with ELT (Extremely Large Telescope), which is due to come online in 2028. With its 40m mirror, this will revolutionise exoplanet science and allow us to characterise the atmospheres of smaller, cooler, potentially rocky exoplanets for the first time. This will build the foundation for us to explore whether other planets like ours exist elsewhere in the galaxy and we are alone in the universe.