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.

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

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.

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.

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

What is the origin of solar systems?

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

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.

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

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

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

PhD Defence

Walsh

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

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

An international team of astronomers led by scientists from Leiden Observatory has for the first time characterised a dust disk surrounding a young super-Jupiter, which is either a giant planet or brown dwarf. They detected infrared emission from the disk which might indicate that moons may have formed.…

PhD Defence

PhD Defence

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

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…

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…

PhD Defence

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

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.'

PhD Defence

PhD Defence

PhD Defence

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.

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…

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.

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.

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,…

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).

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.

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

A Dutch-led team of astronomers has discovered that high-mass stars are formed differently from their smaller siblings. Whereas small stars are often surrounded by an orderly disk of dust and matter, the supply of matter to large stars is a chaotic mess. The researchers used the Atacama Large Millimeter/submillimeter…

Promotor: Prof. dr. I. Snellen, Co-Promotor: Dr. M. Kenworthy

The Dutch scientist prof. dr. Ewine F. van Dishoeck, Leiden Observatory, Leiden University and Max Planck Institute for Extraterrestrial Physics, will receive the 2018 James Craig Watson Medal from the american National Academy of Sciences (NAS).

In this thesis, we present new laboratory data of interstellar dust analogues.

New ALMA observations show there is ordinary table salt in a not-so-ordinary location: 1,500 light-years from Earth in the disk surrounding a massive young star. Though salts have been found in the atmospheres of old, dying stars, this is the first time they have been seen around young stars in stellar…

Astronomers led by Leiden astronomer Sebastiaan Haffert have directly imaged two planets that are gravitationally carving out a wide gap within a planet-forming disk surrounding a young star. While over a dozen exoplanets have been directly imaged, this is only the second multi-planet system to be p…

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…

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

Sustainable energy from wind and solar is most readily available near the sea.

Beowulf clusters looking for new frontiers.

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…