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

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

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.

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.

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.

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

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…

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.

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.

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.

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

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

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.'

All the planets in our solar system orbit around the Sun in an ecliptical plane. This is to be expected because our solar system was formed from a so-called protoplanetary disc. PhD candidate Anna Miotello has studied these kinds of discs and how they influence the formation of stars and planets. PhD…

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.

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

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

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…

For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disc surrounding a young star. The discovery reaffirms that the conditions that spawned the Earth and Sun are not unique in the Universe. The results are published…

With 8.9 million euros from the Danish National Research Foundation, Aarhus University and Leiden Observatory will establish the Center for Interstellar Catalysis. The centre is led by Aarhus professor Liv Hornekær and aims to find out how and when the building blocks of life formed in the Universe.…

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, researchers at Leiden Observatory in the Netherlands have for the first time detected dimethyl ether in a planet-forming disc. With nine atoms, this is the largest molecule identified in such a disc to date. It is also a precursor…

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

In a New York Times report on a bitter archaeological feud over the Nebra sky disk, Maikel Kuijpers reflects on its importance. 'It’s really unfortunate if we put all our focus on one exceptional status object. I think that’s not helping our discipline.'

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

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…

PhD Defence

Walsh

PhD Defence

PhD Defence

PhD Defence

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).

PhD Defence

Professor Ewine van Dishoeck, together with an international team of colleagues, has written an overview of everything we know about water in interstellar clouds thanks to the Herschel space observatory. The article, published in the journal Astronomy & Astrophysics, summarizes existing knowledge and…

PhD Defence

PhD Defence

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…

This book explores chronologically, for the first time, the representation and redefinition of Indonesia’s regional cultures through recording media, from the introduction of the gramophone record through the current video compact disc (VCD) era, taking as case study the Minangkabau ethnic group.

Promotor: A. Kros

Electrocatalysis allows for storing electricity or converting it into chemical bonds, producing chemical building blocks and fuels using renewable resources.

Promotor: Prof.dr. P.G.L. Klinkhamer, Co-Promotor: T.J. de Jong

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.

Leidse lezingen over de Arabische taal en cultuur | 2019 (I)

When stars are born, large clouds of gas and dust form that are known as circumstellar discs. Research by PhD candidate Francisca Concha-Ramírez shows that strong radiation from neighbouring stars soon evaporates the dust in these discs, which can prevent planet formation at an early stage. PhD defence…

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.