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

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.

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.

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

This research focuses on the distribution of chemical elements in protoplanetary disks, the birthplaces of planets. These disks form around young stars and contain gas and dust, from which planets grow. Ice plays a crucial role in planet formation, aiding the clumping of dust particles and influencing…

The zoo of detected exoplanets reveals both the uniqueness of our own Solar System and the complexity of planetary system formation, sparking fundamental questions about how planetary systems form and evolve.

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

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

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

Many protoplanetary discs in which new planets are formed are much smaller than thought. Using the Atacama Large Millimeter/submillimeter Array (ALMA) scientists of the Leiden Observatory looked at 73 protoplanetary discs in the Lupus region.

A Humanities degree gives you a solid start on the job market. Here you can find up-to-date information about Humanities graduates on the job market, as well as alumni stories.

Protoplanetary disks are the gas and dust environments where planetary systems form around young stars. Using observations from the Atacama Large Millimeter/submillimeter Array (ALMA) this thesis analyses the gaseous molecular reservoir, using multiple tracers to resolve the 3D structure of protoplanetary…

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

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

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.

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…

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.

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.

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

Martijn Junte defended his thesis on 21 September 2017

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

The formation of stars and planets happens over multiple scales, which can interact. In particular, planet formation happens in the dense, complex environment of star forming regions.

In the past decade many population studies have been performed with the Atacama Large Millimeter/submillimeter Array (ALMA) to understand the bulk properties of protoplanetary disks around young stars. These population studies mostly consisted of low mass stars, with relatively few of the disks around…

Astronomy began by studying the light from the stars. These stars are born in vast clouds of gas and dust.

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

This thesis focusses on the temperature structure in protoplanetary disks. The relation between structures seen in the dust and gas-phase molecules is investigated.

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.

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

On 17 October 2018, Thomas Sanders defended his doctoral thesis 'Invordering door de overheid: de invordering van geldschulden uit herstelsancties onder de Awb'. The doctoral research was supervised by Prof. mr. T. Barkhuysen and Prof. mr. M.W. Scheltema.

Michiel Pronk defended his thesis on 30 March 2016

This thesis is a (biased) journey through very different topics in astrophysics: quasars and new populations of active galactic nuclei, gravitational waves from merging black holes, and protoplanetary discs around young stars.

High-angular-resolution observations of the circumstellar material have uncovered numerous and very diverse substructures in protoplanetary discs, raising the question of whether they are caused by forming planets or other mechanisms.

In the disk surrounding the young star WISPIT 2, not one but two planets are taking shape. Leiden PhD candidate Richelle van Capelleveen played a key role in this discovery, providing a rare glimpse into the early stages of planetary system formation.

Last week, the Old Observatory Leiden concluded its participation in Stage 1 of the DOORS Incubation Programme. Our team has spent the last three months learning about how to successfully implement digital practices into their work to improve our audience engagement. The workshops introduced important…

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

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…

Announcement

A team of scientists, including Leiden Astronomer Alice Booth, has discovered silicon monosulfide molecules in the dust disk around a young star. Such molecules indicate planet formation. The team made the discovery using the ALMA telescopes. This method provides an alternative when direct observation…

Noah Millman defended his thesis on 26 May 2015

All comets might share their place of birth, new research says. For the first time ever, astronomer Christian Eistrup applied chemical models to fourteen well-known comets, surprisingly finding a clear pattern. His publication has been accepted in the journal Astronomy & Astrophysics.

On Thursday the 29th of October, Kennis Maken Den Haag organises the third edition of Den Haag Draait Door. In this online talk show, experts and policymakers will discuss problems that exist in the city of The Hague. During this edition, as usual, students, researchers and residents from the region…

‘Dutch municipalities’ backroom meetings a massive breach of the law’ was the main headline of Dutch newspaper De Stentor on 24 June 2022. According to investigative journalist Gep Leeflang, Dutch municipalities continuously break the law by holding their municipal council meetings behind closed doors.…

In the tv show 'De wereld draait door' of Tuesday 4 February, Prof. Hendrik Lenstra, together with Prof. Barry Koren, gave an explaination of the so-called 'Millenium Problems'.

Our solar system probably evolved in the same way as most of the other planetary systems around us. This has been shown by German-Austrian-Dutch research on more than 870 planet-forming disks in the Orion cloud A. The five researchers, including three from the Leiden Observatory, published their findings…

What is it like to participate in the Erasmus+ grant programme as a Master's student from Ukraine? Yevhenii Radchenko did an eight-month internship at Leiden University in 2018. Soon after, he returned as a PhD candidate. 'You have little to lose, but a lot to gain.'

Astronomers led by Leiden PhD candidate Richelle van Capelleveen have, for the first time, discovered an exoplanet that has carved a bright gap in the protoplanetary disc around its star. This rare observation provides new insights into how young planets shape their surroundings.

Astronomer Jos de Boer has received the Chesneau Prize in Nice for his research into so-called protoplanetary disks. The prize is awarded to the best astronomical dissertation in the field of high angular resolution. 'I consider it a good opportunity to talk about my research.'

Political scientist Tim Mickler (Leiden University) receives a grant from The Dutch Research Council (NWO) for his quantitative research into post-parliamentary positions of parliamentarians. The grant is a result of the SGW Open Competition XS, with the aim of stimulating innovative scientific rese…