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.…

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…

Take a journey through the history and future of life on planet Earth.

Crises like climate change and loss of biodiversity threaten our planet. That’s why sustainability is an important topic in research and education across Leiden University. On this website you read how scientists from many disciplines work together in researching sustainability.

Join us for Liveable Planet lunch meetings: Liveable communities. We will organise a monthly lunch meeting to inspire and build a sustainability community at the University Leiden.

The Liveable Planet programme assists scientists and local communities in taking up a collective responsibility to develop in a sustainable way. This is done together with a lot of scientist from various disciplines.

Are you a young researcher at Leiden University doing research on sustainability topics? Or are you part of the support staff and passionate about sustainability? Then we are looking for you!

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.

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…

In the large gas clouds between the stars, chemical reactions take place under extreme conditions, giving rise to both small molecules, such as water and common salt, as well as large complex molecules that can serve as the building blocks of life. This is known as astrochemistry and it is something…

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.

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

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

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

Low-mass main-sequence stars like our Sun are continuous sources of outflowing hot magnetised plasma. In the case of the Sun, this is known as the solar wind, whereas for other stars they are called stellar winds.

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.

Promotor: Prof.dr. G.R. de Snoo, Co-promotor: R. Heijungs

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

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

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

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

Leiden University has participated in an international study carried out by the CARMENES consortium, which has discovered two small, terrestrial planets around Teegarden’s Star. The planets have masses similar to Earth and their temperatures could be mild enough to sustain liquid water on their surf…

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…

Even though more than 4000 extra-solar planets are known today, only a small fraction of these has been captured in an image. To better understand the planet formation mechanisms in solar-like environments we started the Young Suns Exoplanet Survey (YSES).

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…

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

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.

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…

The Plants & Planets exhibition brings two worlds together in a dazzling mix of science, nature and art. It opens at Old Observatory Leiden and Hortus botanicus on 7 February.

What is the relationship between humans and nature like? And how can we use it to tackle climate problems? In the Master Honours Class ‘Planet in Peril’, students approach climate issues from the perspective of the humanities. ‘Things are not always as one-sided as they seem.’

Many hot, rocky planets outside of our own solar system started out as large, gaseous Neptunes. This is what astronomers at Leiden University contend in a recent online publication.

It is theoretically possible that habitable planets exist around pulsars, rotating neutron stars. Such planets must have an enormous atmosphere that convert the deadly X-rays and high energy particles of the pulsar into heat. That is stated in a scientific paper by astronomers Alessandro Patruno and…

Scientists from all different disciplines at Leiden University work on sustainability challenges. Together we strive for a liveable planet by connecting these scientists. Are you a researcher and do you want to contribute to tackling sustainability issues? Join our program and work together on solutions…

Northern lights, stellar winds and exoplanets. This is what astronomer's PhD research revolved around. PhD candidate astronomer Rob Kavanagh developed mathematical models to better understand the interactions between exoplanets and stellar winds and to define features of exoplanets. He will receive…

LUGO got the opportunity to present the Green Paper at the third lunch session of the Liveable Planet initiative on the 25th of May.

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…

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…

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.

On 21 October 2021, Shiming Yang joined the liveable planet lunch meeting. She talked about China’s international commitment and domestic climate policies. She examined a small yet important sector –the cooling sector. As Global Warming continues, the demand for cooling systems increases, but the main…

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.

Dumb island birds, invasive species dressed as cute purple flowers, and trees the size of skyscrapers. What better way to end your summer and start the new academic year than by discussing, scavenging, and observing these topics. This is exactly what the PhD candidates of Young Liveable Planet (YLP)…

The ALMA Local Expertise Group (Allegro) is located in the Leiden Observatory (Sterrewacht). Professor Ewine van Dishoeck: ‘The Netherlands has played an important role in establishing ALMA. Thanks to this subsidy, we can now reap the scientific benefits.'

The publication of the recent IPCC report on climate change has not gone unnoticed, to put it mildly, certainly not within the Liveable Planet community.

A remarkable population of short period transiting rocky exoplanets with equilibrium temperatures on the order of 2,000 K has recently been discovered.

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.

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