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…

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.…

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.

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

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.

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.

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.’

Could water be present in planet-forming disks before the formation of rocky planets? The James Webb Space Telescope may have found evidence for that. Webb has for the first time observed water in the inner disc around young star where at greater distance, giant planets have already formed. The research…

The discovery of a planet far too large for its sun defies models about the formation of solar systems and planets. In a paper in Science, researchers, including Yamila Miguel of Leiden Observatory, report the discovery of a planet more than 13 times heavier than Earth orbiting the ultracool dwarf star…

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.

Which molecules go into forming planets? PhD candidate Christian Eistrup and his colleagues have created new models to research this question. Their findings could change our idea of which molecules were forming Jupiter or even Earth.

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.

An international team of astronomers led by Ardjan Sturm of the Observatory has made the first two-dimensional inventory of ice in a planet-forming disk of dust and gas surrounding a young star. The researches, including Melissa McClure, used the James Webb Space Telescope and publish their findings…

‘Solar panels, toothpaste and sport socks. What do these things have in common?’ Martina Vijver, professor of ecotoxicology begins her TEDx-talk. Watch her online lecture if you want to learn more about the effects of nano-particles on our environment and health.

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…

Planets existing in other solar systems contain invaluable information about the origin of planets and life. PhD candidate Yapeng Zhang has studied their atmospheres by looking at their smallest parts: isotopes. With her research she hopes to discover what makes our own solar system unique.

A team of international researchers led by Tomas Stolker in the Netherlands has imaged a young gas giant exoplanet near a 12-million-year-old star. The planet is orbiting a star at which planet formation has finished, while the same-aged companion star still has a planet-forming disk. The researchers…

Aline Vidotto has been appointed professor of Stellar and Planetary Astrophysics at the Observatory from 1 February. Vidotto has been with the university for 3.5 years and for her, the appointment is ‘a milestone in her career.’

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…

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.