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.

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,…

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…

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…

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

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.

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…

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.

Research truly comes to life when it contributes meaningfully to society. By sharing our findings, advising policymakers or contributing to community projects – we can make a real impact. Scroll down and discover how Science and society can mutually benefit from each other.

The Leiden Science Young Talent Award is awarded yearly to a student who completed their bachelor’s degree with an excellent thesis.

Is it possible to formulate a new conceptual foundation for attributing an evaluative role to historiography of science, without relinquishing the historiographic sensitivity of recent work in the discipline?

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…

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…

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.

By carrying out fundamental research and providing excellent education, universities become a breeding ground for innovation and entrepreneurship.

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…

Astronomers have discovered seven Earth-like planets around a dwarf star in our galaxy. Three of these planets are located in the habitable zone of this star, and may contain liquid water. ‘The next step is to study the atmospheres for signs of life. In Leiden we are experts in that area,‘ says planetary…

The We Are Science Week, inspiring lectures, and enjoyable gatherings. This year, we frequently came together to inspire and connect with one another. Our biggest event took place at the start of the academic year in September: the official opening of our new Gorlaeus building.

The first photo of a black hole and measuring anxiety in the brain... From 13 until 22 May we're serving a free slice of science with your pizza.

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…

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

She left Leiden after her PhD and now, 14 years later, she returns as Professor of Extragalactic Astronomy. Mariska Kriek investigates how galaxies originate and evolve. And she is eagerly awaiting the launch for the new James Webb telescope: ‘The coolest things we are going to find are those we’re…

What did we do over the past year? Well, we played quantum games, helped develop an instrument for the Extremely Large Telescope and started a new bachelor's programme. Oh, yeah, and we officially opened our brand new Gorlaeus Building! Warm up the fingers and get ready to click and scroll through…

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.

Scientists, including our faculty colleague Dr. Mike Field, studying an exceptionally well-preserved woolly rhinoceros have revealed details of what Britain's environment was like 42,000 years ago. The beast's remains were discovered in Staffordshire in 2002, buried alongside other preserved organisms…

Historiography of science is in its current self-image a non-evaluative discipline. Its main goal is to understand past processes of knowledge formation on their own terms. In the last few decades this approach has greatly improved our understanding of the phenomenon of science. Yet, something strange…

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…

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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.