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.

PhD defence

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

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.

The James Webb Space Telescope has found evidence of carbon dioxide (CO₂) in the atmosphere of a giant planet 700 light years away. This result provides insight into the composition and formation of this gas giant and shows what James Webb is capable of. The research by the international group of astronomers,…

Unethical conduct by traders at banks is likely to be a continual problem as long as fraud cases are treated as the fault of a single rotten apple. Improving the team atmosphere reduces the likelihood of improper behaviour. This is the finding of psychologist Wieke Scholten from Leiden University in…

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…

Advancing AutoML systems targeting machine learning tasks based on Earth Observation (EO) Datasets.

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.

To look for atmospheres around planets outside our solar system is to look for extraterrestrial life. Astronomist Sebastian Zieba used data from the James Webb Space Telescope to study small rocky exoplanets but found no aliens yet. However, his findings are still very interesting for future observations.…

Researchers using NASA’s James Webb Space Telescope may have detected atmospheric gases surrounding 55 Cancri e, a hot rocky exoplanet 41 light-years from Earth. This is the best evidence to date for the existence of any rocky planet atmosphere outside our solar system.

An international team of astronomers have become the first in the world to detect isotopes in the atmosphere of an exoplanet. It concerns different forms of carbon in the gaseous giant planet TYC 8998-760-1 b. The research will be published in the scientific journal Nature on Thursday.

Promotor: Prof.dr. C.U. Keller, Co-promotor: Dr. ir. Frans Snik

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

On February 24, 2017, the Institute of Biology Leiden organised the first edition of the Biology Career Event. The career event for third year bachelor and master students was well received by the attendants. ‘I felt that the presenters and people doing the workshops were really trying to help us get…

In our globalised economy, goods and services are frequently produced abroad. Is it the producer or the consumer that should be held responsible for greenhouse gas emissions associated with production? Together with colleagues from Berlin, Hauke Ward of the Institute of Environmental Sciences (CML)…

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,…

From a lovely blossoming garden in Barcelona, Eduard Fosch Villaronga is talking enthusiastically about his postdoc at Leiden University. Due to the corona lockdown, he is currently spending the 2020 summer at his mother’s place, but he is looking forward to returning to Leiden (and to the Dutch bit…

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.

An international team of astronomers has revealed the first 'chemical profile' of an exoplanet's atmosphere. The team, including Leiden astronomer Yamila Miguel and provenda Amy Louca, made the profile using so-called Early Release Science data from the James Webb Space Telescope. The results have been…

Twee teams of astronomers, including from the universities of Amsterdam and Leiden, have discovered how hot gas giants are surrounded by large halos of thin helium gas, an indication that they are slowly losing their atmosphere. The helium, that was recently seen for the first time by the Hubble space…

A radical reduction in the amount of meat, dairy and other products sourced from animals is possible in the coming decades, as people turn to an increasing variety of alternatives. This would unlock vast amounts of land that we could use to produce energy and remove carbon from the atmosphere. Leiden…

Thomas Vorisek is a video coordinator. He picked up a new hobby in his student days, entirely by coincidence, and now he makes a living out of it. Thomas likes to spend his free time on the beach.

Professor Herman Paul has been appointed Scientific Director of the Institute of History from 1 February 2025. ‘Especially in these times, transparency is essential.’

An international team of researchers led by astronomers from Leiden University (the Netherlands) has produced the first sharp radio maps of the universe at low frequencies. Thanks to a new calibration technique, they bypassed the disturbances of the Earth's ionosphere. They used the new method to study…

So many interesting programmes, but which one suits me best? It was the Bachelor’s Open Day in Leiden and The Hague on Saturday 12 October. Among the many things to do in The Hague, prospective students could find out more about three new bachelor’s programmes: Science for Sustainable Societies, Cybersecurity…

PhD defence

PhD defence

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

Lecture, Research Seminar

This thesis focus on the interaction between M dwarf stellar winds and Galactic cosmic rays and the possible effects on the habitability of exoplanets.

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

To study how planetary systems come into existence we study much younger systems still in formation.

In what ways can a photographic practice act as a means to confront, or even undo, the various material properties of atmospheric enclosure that so clearly put our relationship with our environment under pressure? Is it possible to devise a set of critical and artistic strategies to comprehend the ways…

This thesis is about the study of hydrocarbons via infrared spectroscopy.

Lecture

These are the proposed research projects for LEAPS 2019. Please note that not all projects will go ahead and some may still be added in the near future. Final funding decisions lie with the Faculty sponsors. And please make a note that if you are interested in an ESA project, to check if your state…

Is there extra-terrestrial life out there? It now looks as though we can sketch out an answer to this enduring question. Leiden Observatory is helping to build new instruments to find the most promising exoplanets.

Leiden University began the construction of a new University Sports Centre in collaboration with the construction and design firm Binx Smartility. The current sports center no longer meets sustainability requirements and is also becoming too cramped. The building will also serve as an examination ce…

Research at the Leiden Institute of Physics (LION) is foundational and curiosity driven. All our scientists share a desire to increase the knowledge of the world around us, in an open atmosphere of inquiry from which innovative ideas emerge that provide applications and value for society.

Within the two-year Astronomy master’s programme, you can choose from seven specialisations, ranging from fundamental or applied astronomy research in cosmology, instrumentation or data science, to combinations of astronomy research with education, management or science communication.

Most degree programmes at the Faculty of Social and Behavioural Sciences are based in the Pieter de la Court building on the Wassenaarseweg in Leiden. Besides this location, some degree programmes are based in The Hague, at Campus The Hague’s Wijnhaven building.

Lecture

We are pleased to announce that the ENPAIR Conference 2026 will be hosted and organized by colleagues from the University of Prešov, Slovakia. The conference will take place on 17–18 September 2026 at Galéria Umelka in Bratislava, capital city of Slovakia. The conference the will be: