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 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.

This dissertation presents the results of the importance of creativity for ICT-students of Dutch universities of applied sciences (in Dutch: hogescholen), and the functioning of training courses that aim to promote creative abilities is highlighted.

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…

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…

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…

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.

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.

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.

Wordt het nog wat met de Arabische lente?

Meerdere kranten schrijven over een onderzoek van Wimar Bolhuis naar de Nederlandse belastingopbrengsten.

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…

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.

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

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…

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…

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…

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…

No joke: on 1 April, the antique Van de Wall telescope was relocated to the atrium of the Gorlaeus Building. Have you spotted it yet?

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

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).

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.

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…

Leiden scientists and companies receive 1.37 million euros to develop technology for the Einstein Telescope. This underground telescope will measure gravitational waves and must therefore be extremely sensitive. To that end, the consortium conducts research on the damping of vibrations at temperatures…

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.

How do stars and galaxies form? What is dark matter? To answer these and other questions, we need increasingly large telescopes. And to build these, we need international partnerships. A series on the impact of collaboration.

Scientists have detected a neutrino with the highest energy ever measured. Leiden physicists Maarten de Jong and Dorothea Samtleben were involved in this project, which was widely covered in newspapers and online media last week.

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.

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…

Leiden Observatory has achieved a rare feat: two of its research teams have been awarded prestigious ALMA Large Programmes, allowing them to study how galaxies formed and evolved in the early Universe using cutting-edge telescope observations.

Rychard Bouwens from the Leiden Observatory is the first scientist in the Netherlands to be assigned a Large Programme on the state-of-the-art ALMA telescope in Chile. With his team, he wants to use the unique capabilities of the billion-euro facility to investigate the build-up of massive galaxies…

Space telescope Euclid is capable of unravelling the secrets of the universe. That is what the images published by ESA today show, according to astronomers working with the telescope's data. The images exceed all expectations. Scientists within the Euclid consortium, including astronomers Henk Hoekstra…

The Leiden Science Young Talent Award celebrates a student who completed their bachelor’s degree with an outstanding thesis.

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).

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.

To strenghten ties with the public, press, other academics and wider society, LION employs an outreach officer.

This thesis describes the Multi-site All-Sky CAmeRA (MASCARA), which consists of two small robotic telescope designed to detect exoplanets around the brightest stars in the sky.