Promotor: Prof.dr. I.A.G. Snellen, C.U. Keller

Over the last three decades, the discovery of exoplanets has revealed the boundless variety of worlds beyond our own Solar System⁠. Majority of planetary systems contain short-period planets that are larger than Earth but smaller than Neptune⁠.

More than 5,000 exoplanets have been found over the past couple of decades. These exoplanets show a tremendous diversity, ranging from scorching hot Jupiters, common super-Earths, to widely separated super-Jupiters on the planet/brown dwarf boundary.

One of the key discoveries in exoplanet research over the past decade is the abundance of small planets in our Milky Way. Despite their high numbers, our understanding of their atmospheres remains limited, and it is unknown if they possess atmospheres at all.

In the past 30 years, over 5,000 planets have been discovered outside our solar system. One common exoplanet is the lava world, a hot super-Earth with oceans of liquid lava. Mantas Zilinskas developed models to simulate possible atmospheres of these. Those simulations provide guidance for astronomers…

This thesis describes the implementation and on-sky demonstration of high-resolution integral-field spectroscopy for extreme adaptive optics systems that are used to find and characterize exoplanets.

A group of astronomers led by Leiden PhD student Sebastian Zieba has discovered using the James Webb Space Telescope (JWST) that the rocky exoplanet TRAPPIST-1 c has a thin atmosphere. Although the planet is nearly identical to Venus in size and temperature, and was expected to have a thick atmosphere,…

Promotor: I. A. G. Snellen, Co-promotor: M. A. Kenworthy

Diverse types of exoplanets such as gas giants on close-in orbits (hot Jupiters) and young massive giants on wide orbits (super Jupiters), with no analogs in the Solar System, pose challenges but also opportunities to our understanding of planet formation and evolution.