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).

The Old Observatory houses four historical telescopes. On this page you can learn more about them.

Our current research focusses on the exploration of the Universe using the neutrino. This neutral, almost massless and only weakly interacting particle can open a window to the distant Universe and also dense regions from which photons cannot escape.

A new way to decipher the light from distant worlds could give us unmistakable evidence of extraterrestrial photosynthesis, and maybe alien plants, finds astronomy author Colin Stuart in the New Scientist. In his article, he describes the work of the group led by Leiden astronomer Rob van Holstein.…

With a special symposium at Museum Boerhaave, ESO celebrated its 60th anniversary on Monday, 26 September. More than 100 scientists, politicians and people from industry were present to look back on collaborations, milestones and discoveries. Leiden astrochemist Ewine van Dishoeck was one of the pre…

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.

The design for the METIS instrument for the Extremely Large Telescope (ELT) is final. The European Southern Observatory (ESO) has given the green light for production of all parts of the instrument. It is the first ELT instrument, designed and to be built under Dutch leadership, to formally pass the…

Leiden scientists will be working on the development of a camera for the European Extremely Large Telescope that is currently under construction. On 28 September the Netherlands Research School for Astronomy signed an agreement with the European Southern Observatory.

After nearly 70 years, the Leiden Observatory has a new telescope. A crowdfunding action in March brought in the 20,000 euros required to build a solar telescope. On 19 September Rector Magnificus Carel Stolker officiated at the opening.

To what extent does exoplanet Proxima b resemble our Earth? And is there some form of life present? Astronomers hope to find answers to these questions with the new European Extremely Large Telescope (ELT). An NWO research grant of €18 million will allow a Dutch consortium to continue building instruments…

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…

An international team of astronomers from Leiden Observatory and others, has for the first time mapped a piece of the dark, cosmic web. The research strengthens the hypothesis that the young universe consisted of huge numbers of small groups of newly formed stars. The astronomers publish their findings…

Director General of ESO, Tim de Zeeuw received President of the Republic of Chile, Michelle Bachelet Jeria for a ceremony marking the first stone of ESO’s Extremely Large Telescope (ELT).

An international team led by Leiden astronomers has, after years of searching and defying the boundaries of a telescope, for the first time directly captured polarised light from an exoplanet. From this light they can deduct that a disk of dust and gas orbits the exoplanet. In this disk moons are possibly…

While investigating 16 years of images of young stars from a retired astronomical camera, Leiden master's student Sam de Regt discovered that two of those stars were still enveloped in birth clouds. Never before has anyone captured these two stars in so much detail. He publishes his data-cleaning method…

Promotor: J.N. Kok, Co-promotor: M.S. Lew

An international team led by Leiden astronomers has taken the first-ever image of a young, Sun-like star accompanied by two giant exoplanets. The researchers used The European Southern Observatory’s Very Large Telescope for this, known as ESO’s VLT. Images of systems with multiple exoplanets are extremely…

BplusC Libraries and Old Observatory Leiden working together to provide telescopes

The alignment of the James Webb Space Telescope is complete. The space observatory is able to capture sharp, well-directed images with each of its four powerful scientific instruments on board. The MIRI instrument, on which Professor of Molecular Astrophysics Ewine van Dishoeck also worked, was the…

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.…

In 2015, Jorryt Matthee thought he discovered an extremely distant galaxy called CR7, which lacked elements heavier than helium. Three years later, he shows with measurements using the ALMA telescope that the galaxy does have carbon after all, and even in normal concentrations. The American Astronomical…

New results from the Kilo-Degree Survey (KiDS) show that the Universe is almost 10 percent more homogeneous than previously thought. The new KiDS map was created using the partly Dutch OmegaCAM on ESO's VLT Survey Telescope on Cerro Paranal in Northern Chile. An international team of astronomers from,…

Promotores: Prof.dr. M. Franx, Prof.dr. M. Kriek (Univ. of California at Berkeley)

The 'deepest and sharpest' image of the Universe to date: the first photos from the new James Webb space telescope yesterday mesmerised astronomers and the public alike. Leiden Professor of Molecular Astrophysics, Ewine van Dishoeck, spoke to various media outlets about the first images, which include…

After a period of maintenance, the 'Photographer' telescope is available once again for visits at the Old Observatory.

After a period of maintenance, the 'Photographer' telescope is available once again for visits at the Old Observatory.

The formation and evolution of galaxies is fundamentally driven by the formation of new stars out of cold gas.

Large-scale computing infrastructure, such as supercomputers, cluster, and clouds, are already pervasive, most members of our society interact with them daily: social networks, government services, media streaming services--all systems heavily interfacing with the members of our society--are powered…

Three Dutch-Belgian telescopes have started operating at the ESO La Silla Observatory in Chile. This so-called BlackGEM array will scan the southern sky to hunt for cosmic events that produce gravitational waves, such as mergers of neutron stars and black holes. Leiden astronomer Rudolf le Poole is…

Deep observations made with the MUSE spectrograph on ESO’s Very Large Telescope have uncovered vast cosmic reservoirs of atomic hydrogen surrounding distant galaxies. The exquisite sensitivity of MUSE allowed for direct observations of dim clouds of hydrogen glowing with Lyman-alpha emission in the…

This thesis examines silicon pore optics (SPO), a technology that exploits silicon wafers from the semiconductor industry to create extremely high quality X-ray optics, by studying its manufacturing process, applications, and prospects.

Meet the newest Full Professor at the Leiden Observatory: Joe Hennawi. All the way from Santa Barbara, California, Hennawi will strengthen the astronomy institute. In Leiden, he will use his recent ERC Advanced Grant to study how supermassive black holes come into existence.

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.'

A study into the investment and impact of construction projects on Mycenaean communities in Late Bronze Age Greece

An in-depth history of Large Language Models—and what their ubiquity, disruption, and creativity mean from a wider sociopolitical perspective.

This thesis investigates how galaxies form and what diversifies the evolutionary histories of galaxies.

Promotores: F.H.J. Redig, W.T.F. den Hollander

The Old Observatory in Leiden has reclaimed its most important telescope. Since the 1960s, the Meridian Circle (also known as a transit telescope) had been housed in the Boerhaave Museum. After more than sixty years, the telescope is finally back in its original location. Now, the public can enjoy it…

Understanding the formation and evolution of planetary systems is one of the most fundamental challenges in astronomy. To directly image and study young exoplanets and the circumstellar disks they form from, dedicated high-contrast imaging instruments are built.

After 25 years, December will finally see the launch of the long-awaited James Webb space telescope. Leiden astronomers are watching with great excitement: not only were they involved in the construction of important instruments on board, the telescope will also reveal many new secrets of the universe,…

ESA’s space telescope Gaia, which maps the Milky Way, completes its active phase of scanning the sky on 15 January. Over the past decade, Gaia has made more than three trillion observations of about two billion stars and other cosmic objects. ‘Gaia is already the discovery machine of the decade,’ Leiden…

On Monday 9 May Mercury will pass between the Earth and the Sun. This rare event can be followed in the Leiden Observatory. The Observatory's new solar telescope produces a very clear image and offers a unique opportunity to observe Mercury at the highest magnification possible in the Netherlands.

Paul Hudson, Associate Professor of Physical Geography at Leiden University College, examines human impacts on lowland rivers in his new book.

After years of development, the moment has finally arrived: a massive cryostat, a highly advanced freezer that keeps the sensitive components extremely cold, has arrived in Leiden from Zurich. The device is the largest component of METIS, one of the first instruments for ESO’s Extremely Large Telescope…

The Old Observatory has a rich history. On this page you will find a short version of the history that took place in the observatory.

Astronomers at Leiden University have discovered the first planets using a new instrument: the planet hunter MASCARA. This instrument, developed at Leiden Observatory, looks specifically for planet transitions around the brightest stars in the sky, which surprisingly enough have so far have hardly been…