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

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…

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…

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.

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,…

Lecture, Research Seminar

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…

Even with state-of-the-art technology, it is almost impossible to see: a cosmic neutrino. Yet scientists have managed to image this particle with a deep-sea telescope. And that could help to better understand our universe. Leiden particle physicists collaborated on this ambitious project, published…

In my research I am concerned with the possibility of a politics of sexuality without reverting to identitarian conceptions of sexuality. In a reading of the work of the American author James Purdy, I propose to move towards a politicizing of the concept of narrative identity as developed by the French…

For over a year now, the James Webb Telescope has been sending stunning images that exceed astronomers’ expectations. The photos are fascinating to see, but what exactly are we looking at? Assistant professor Melissa McClure explains.

This research focuses on the distribution of chemical elements in protoplanetary disks, the birthplaces of planets. These disks form around young stars and contain gas and dust, from which planets grow. Ice plays a crucial role in planet formation, aiding the clumping of dust particles and influencing…

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.

BplusC Libraries and Old Observatory Leiden working together to provide telescopes

A team of European astronomers has found a silicate-based weather system on a cloudy gas planet around the star WASP-107. It is the first time astronomers have found silicate clouds and rain. They also conclude that temperatures deeper in the atmosphere are rising rapidly. 'The presence of clouds has…

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.

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…

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.

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…

James Webb life’s building blocks

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.

Astrophysicist Ewine van Dishoeck has been awarded an honorary doctorate from the University of Geneva. She received the award on 11 October during the Dies academicus of the Swiss university, which, like Leiden University, is part of the European research university federation LERU.

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.

Adopting a largely chronological approach, Gerrits links the historiography of post-war Europe and the major theoretical approaches to nationalism with analysis of key historical developments and events.

How do galaxies form? That is what astronomer Mariska Kriek will be researching in the coming years. She received an NWO Vici grant of 1.5 million euros to study galaxies in the early universe. ‘This research uses new and unprecedented observations from the James Webb Space Telescope (JWST). These allow…

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…

From the birth of the universe to the molecules in a planet's atmosphere. The first five pictures from the James Webb Space Telescope (JWST) show the enormous range in which the space telescope can operate. Ewine van Dishoeck, professor of molecular astrophysics, took a look at the first images Tuesday…

Large telescopes can look so deep into the Universe that they can also look back billions of years in time. From 2018, the successor of the Hubble Space Telescope, the James Webb Space Telescope, will be able to see the period just after the Big Bang, when the first stars and galaxies formed. Astronomers…

A star does not just appear in the sky overnight. Its creation takes tens of thousands of years. Twenty years ago, astronomers took a picture of a star in its birth phase. The James Webb Space Telescope (JWST) could now capture that same star in much greater detail. This does not only provide beautiful…

An international team of astronomers has revealed the first 'chemical profile' of an exoplanet's atmosphere. The team, including Leiden astronomer Yamila Miguel and provenda Amy Louca, made the profile using so-called Early Release Science data from the James Webb Space Telescope. The results have been…

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.

Astronomers have captured a new deep field of Pandora's Cluster (Abell 2744) with the James Webb Space Telescope. The images show never-before-seen details. The results are described in four scientific papers. Leiden astronomers Marijn Franx and Mariska Kriek collaborated on the study. 'This opens a…

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…