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…

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.

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…

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.

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…

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…

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

BplusC Libraries and Old Observatory Leiden working together to provide telescopes

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…

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

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…

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.

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…

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

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,…

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.

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…

Until the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial efforts have been made to explore these strange new worlds through spectroscopic analyses of their atmosphe…

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

For the first time in over half a century, one of oldest telescopes at the Leiden Observatory is getting a major improvement.

The Leiden astronomer Huib van Langevelde) has been selected as the new director of the Event Horizon Telescope (EHT). The EHT is a collaboration involving about 350 scientists from 18 countries. It combines the ALMA array in Chile with sub-millimeter telescopes around the world and published the first…

For the first time more than half century, one of oldest telescopes at Leiden Observatory is getting a major improvement.

Everyone wherever they are in the world can follow free online academic courses offered by Leiden University.

The Netherlands Organisation for Scientific Research NWO allocates nearly € 19.5 million to a Dutch cluster that contributes to the development of an X-ray camera and spectrograph for the new European space telescope Athena. Leiden Observatory is one of the members of the cluster.

Astronomers from, among others, SRON and Leiden Observatory have discovered long-sought intergalactic gas with ESA’s space telescope XMM-Newton. This gas is one of the pieces of the puzzle to map the total amount of ‘normal’ matter in the universe. The research will be published in Nature on 21 June…

The strangest things come out at night. This is the motto of the Leiden Museum Night due to take place on 28 May. Leiden University is once again playing a key part.

KM3NeT is selected as one of the ten top research facilities in NWO’s National Roadmap for Large-scale Research Infrastructure. Leiden physicist Dorothea Samtleben is the deputy program leader of Nikhef’s KM3NeT group.

Promotor: W.Th.F. den Hollander Co-Promotor: F.M. Spieksma

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.