This thesis focuses on protoplanetary disks: flattened structures of gas and dust around young stars in which planets are expected to form and grow.

The work presented in this thesis is based on ALMA surveys of protoplanetary disks in three star-forming regions: Lupus, OMC-2, and NGC 2024.

Promotores: Prof.dr. A.G.G.M. Tielens, Prof.dr. L.B.F.M. Waters (UvA), Prof.dr. C. Dominik (UvA)

My work focuses on a class of astronomical objects called protoplanetary disks.

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

What is the origin of solar systems?

This thesis examines the link between simple molecules and the underlying structure and chemistry within protoplanetary disks - the birthplaces of planets.

To address the fundamental questions of how life on Earth emerged and how common life may be in the Universe, it is crucial to know the chemical composition of the planet-forming material.

A large diversity of exoplanetary systems has been found, but it is still unclear what drives this diversity.

The focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed.

Promotores: Prof.dr. E.F. van Dishoeck, Prof.dr. C.P. Dullemond

Planets are formed in disks of gas and dust around young stars.

This thesis discusses the physical and chemical processes than influence the composition of forming planets.

This thesis takes steps toward understanding the interaction between gas-phase and solid-state molecules in star- and planet-forming regions.

Promotor: Prof.dr. E.F. van Dishoeck, Co-promotor: S. Bruderer

Promotor: E. F. van Dishoeck, Co-promotor: C. Walsh

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

Promotor: C.U. Keller, Co-Promotor: F. Snik

In the discs of dust and gasses around young stars, mysterious structures occur. Together with professor Ewine van Dishoeck, PhD student Paolo Cazzoletti investigate how we can explain these forms, such as rings, spirals and holes. On 12 December, he will defend his thesis.

Multiple stars, that is two or more stars composing a gravitationally bound system, are common in the universe.

Understanding the formation and evolution of planetary systems is one of the most fundamental challenges in astronomy. To directly image and study young exoplanets and the circumstellar disks they form from, dedicated high-contrast imaging instruments are built.

We have conducted a full spectral line survey of the 3-13 micron region of two massive protostars, AFGL 2591 and AFGL 2136, for the first time at high spectral resolution.

Promotor: Prof.dr. E.F. van Dishoeck, Co-Promotor: M.R. Hogerheijde

An international team of astronomers including Leiden scientists publishes the image of a young star with a surrounding dust disk that is still being fed from its surroundings. The phenomenon around the star SU Aur may explain why so many exoplanets are not neatly aligned with their star. The European…

A team of European astronomers under Leiden leadership has discovered that dust particles around a star already coagulate before the star is fully grown. These agglomerated dust particles are the first step in the formation of planets. The research publish their discovery in the journal of Nature As…

The bi-annual interactive seminars of the Platform for Postcolonial Readings are all about sharing our enthusiasm about our field of research and our eagerness to learn more about its theoretical intricacies. Our seminars, although informal, adopt a well-defined format. Each meeting is organized around…

Planet formation is a surprisingly homogeneous process that does not take place gradually from inside out, but that occurs everywhere at the same time in a proto-planetary disc, as Dave Lommen has discovered. He will obtain his doctorate this week based on his research into the dust around young stars…

When a star gets too close to a supermassive black hole, it is torn apart by strong tidal forces in a tidal disruption event (TDE).

At Leiden Observatory, researchers investigate the origin of stars and their planetary systems. They detect and characterize planets around other stars, which are called exo-planets. They study how stars and planets form. And they follow molecules from interstellar clouds to nascent planet systems.…

Galaxies form and evolve through close interaction with their surroundings. As a result, the heavy elements ('metals') that are synthesized in stars, are found both inside and outside galaxies.

At Leiden Observatory, researchers investigate the origin of stars and their planetary systems. They detect and characterize planets around other stars (exoplanets). They study how stars and planets form. And they follow molecules from interstellar clouds to nascent planet systems. This way they address…

This thesis investigates how galaxies form and what diversifies the evolutionary histories of galaxies.

An international team of astronomers, including Leiden’s Christian Ginski, has discovered previously unobserved structures in a debris disk around a nearby star. Article published in Nature on 8 October.

One of the key quests in astronomy is to study the growth and evolution of galaxies across cosmic time. Radio observations provide a powerful means of studying the formation of stars and subsequent buildup of distant galaxies, in a way that is unbiased by the presence of dust.

PhD Defence

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…

Some species of proteins which can form liquid-like condensates, also exhibit growth into fibers (or fibrils). One particularly interesting set of such proteins are those that are associated with neurodegeneration in which the fiber growth may be related to the pathological fibrils observed in disea…

Walsh

Promotores: Prof.dr. J. Schaye, Prof.dr. S.D.M. White (MPA Garching)

Promotor: J. Schaye

Research using the ALMA telescope by scientists including Leiden's John Tobin and Steven Bos has produced the first images of the water snow line within a protoplanetary disc. Publication in Nature on 14 July.

Navarro Paredes

Circumstellar discs are the reservoirs of gas and dust that surround young stars and have the potential to become planetary systems.

An international team of researchers led by Alice Booth (Leiden University, the Netherlands) have discovered methanol in the warm part of a planet-forming disk. The methanol cannot have been produced there and must have originated in the cold gas clouds from which the star and the disk formed. Thus,…

Promotor: Prof.dr. E. F. van Dishoeck, Co-promotor: A. N. Heays

PhD Defence

PhD Defence

The FOI project has a number of topics it aims to investigate. These are: State, Economy, Culture and Papyri. You will find links to bibliographies on this page.

People in Asia increasingly feel the need for a strong identity. This is the consequence of developments such as globalisation and the realisation that Asian countries such as China and India are becoming new world powers. Professor Hilde De Weerdt studies how political ideas and national identity spread…

Politically speaking, the Frisian coastal area constitutes a special case in late medieval Europe since it was not subject to an overlord as it withstood feudalization in the 13th century. Its many sub regions, which were dominated by elites of small noblemen and freeholders, long time succeeded in…