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.

This thesis investigates the evolution and fate of gaseous exoplanets, which are continuously shaped by stellar activity across both short and long timescales.

Promotor: Prof.dr. C.U. Keller

Promotores: Prof.dr. C.U. Keller, Prof.dr. H.C. Gerritsen

Promotor: Christoph U. Keller, Co-promotores: Matthew A. Kenworthy, Frans Snik

This thesis describes the development and validation of new high-contrast imaging techniques, with the ultimate goal of enabling the next generation of instruments for ELT-class telescopes to directly image Earth-like extra-solar planets orbiting around nearby stars.

This thesis aims to demonstrate how the achromatic nature and design flexibility of liquid-crystal optics can be used to improve high-contrast imaging instruments to facilitate detailed exoplanet characterization.

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.

This thesis addresses the chemical processes that determine the compositions of giant planet atmospheres.

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

Hot rocky exoplanets are planets that orbit so close to their host star that they possess a molten surface.

Detecting planets during their formation stages is crucial for understanding the history and diversity of fully developed planetary systems like our own. However, observing young planets directly is challenging because they are often deeply embedded within their host protoplanetary discs, rich in gas…

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.

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.

Even though more than 4000 extra-solar planets are known today, only a small fraction of these has been captured in an image. To better understand the planet formation mechanisms in solar-like environments we started the Young Suns Exoplanet Survey (YSES).

Promotor: I. Snellen, Co-Promotor: M. Kenworthy

A remarkable population of short period transiting rocky exoplanets with equilibrium temperatures on the order of 2,000 K has recently been discovered.

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.

De Leidse exoplaneetonderzoeker Frans Snik krijgt een Starting Grant van de European Research Council (ERC). Met de beurs van 1,5 miljoen euro gaat hij technologie ontwikkelen om de atmosferen en oppervlakken van aardachtige exoplaneten te bestuderen.

Op donderdag 26 april gaf James Kasting zijn Oortlezing in het Academiegebouw. Kasting was twee weken in Nederland omdat hij was uitgenodigd als Oort Hoogleraar 2018.

Maar liefst vier wetenschappers ontvangen een TOP-subsidie Exacte Wetenschappen van NWO. Het gaat om astronoom Ignas Snellen, wiskundigen Tim van Erven en Charlene Kalle en informaticus Siegfried Nijssen. Met het geld worden tijdelijke onderzoeksposities gefinancierd.