As Director-General of the ESO for the past ten years, Leiden University astronomer Tim de Zeeuw had ‘the best astronomy job in the world’. Back at the Leiden Observatory, he is focusing on the first 3D map of the Milky Way.

On this section of the website you can find more information about the Old Observatory and the current astronomy research institute.

Promotor: M. de Jong, Co-Promotor: Samtleben

‘The Oscars of the natural sciences’, is what they are called: the Breakthrough Prizes awarded annually in America by the Breakthrough Foundation. Part of this are the New Horizons prizes for early-stage researchers. Sebastiaan Haffert, researcher at the Observatory, is this year's winner.

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…

Discovering what is inside giant planets and their atmosphere, that is one of the goals of astronomer Yamila Miguel. With an ERC Consolidator Grant of 2 million euro, she will study giant planets both inside and outside our solar system. ‘We want to know more about how planetary systems are born, how…

The Old Observatory is still used intensively as a university building. Yet there is still plenty to see and experience in this beautiful monument. Find out what the possibilities are here.

Leiden has a strong tradition in theoretical physics, thoroughly linked with experimental disciplines.

Every month there is an opportunity to visit the Old Observatory in the evening. These open evenings consist of a lecture followed by a visit to the telescopes in the building.

This thesis describes the implementation and on-sky demonstration of high-resolution integral-field spectroscopy for extreme adaptive optics systems that are used to find and characterize exoplanets.

In the large gas clouds between the stars, chemical reactions take place under extreme conditions, giving rise to both small molecules, such as water and common salt, as well as large complex molecules that can serve as the building blocks of life. This is known as astrochemistry and it is something…

Astronomers led by Leiden PhD candidate Richelle van Capelleveen have, for the first time, discovered an exoplanet that has carved a bright gap in the protoplanetary disc around its star. This rare observation provides new insights into how young planets shape their surroundings.

Two teams of astronomers, including one from Leiden University, have discovered oxygen in the most distant known galaxy, JADES-GS-z14-0. This groundbreaking discovery shows that galaxies could form much faster in the early universe than was previously thought.

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…

An international team of astronomers led by Ardjan Sturm of the Observatory has made the first two-dimensional inventory of ice in a planet-forming disk of dust and gas surrounding a young star. The researches, including Melissa McClure, used the James Webb Space Telescope and publish their findings…

The Dutch-Japanese made DESHIMA instrument has passed its first practical tests when measuring the distances and ages of distant galaxies. The core of the instrument is a chip the size of two euro coins that measures 49 shades of far infrared light. The developers of the spectrometer publish the results…

Astronomy began by studying the light from the stars. These stars are born in vast clouds of gas and dust.

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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.

The master's specialisation Astronomy and Instrumentation at Leiden University focuses on fully understanding the physical principles and performance of astronomical instruments and to contribute to the development of new instrumentation technologies.

An international team of astronomers led by Violeta Gámez Rosas (Leiden University) has observed a supermassive black hole hidden in a ring of dust. This discovery fits the idea that the so-called active centers of galaxies are much more similar than observations show, because the viewing angle from…

Astronomers led by Leiden astronomer Sebastiaan Haffert have directly imaged two planets that are gravitationally carving out a wide gap within a planet-forming disk surrounding a young star. While over a dozen exoplanets have been directly imaged, this is only the second multi-planet system to be p…

Four different astronomical societies are active in the Old Observatory. We are very proud of the commitment these associations show to organize activities.

‘Space Antenna LISA will open an unprecedented window on the Universe,’ says astronomer Elena Maria Rossi. The mission will be the first one to detect Gravitational Waves from space. These can tell us more about the beginning of our Universe and the formation of black holes. With an NWO grant of twelve…

Leiden Professor of Molecular astrophysics Ewine van Dishoeck has been awarded an Advanced Grant by the European Research Council (ERC). She has been awarded 2.3 million euros in research funding for the MOLDISK programme. Within this programme, Van Dishoeck wants to connect chemistry and physics in…

The new MASCARA-facilty in Chile has achieved first light. This new facility will seek out transiting exoplanets as they pass in front of their bright parent stars and create a catalogue of targets for future exoplanet characterisation observations.

An international team of astronomers, with researchers at Leiden Observatory playing a leading role, has mapped the fuel for galaxy formation in the iconic Hubble Ultra Deep Field. The results of the research have been accepted for publication in The Astrophysical Journal.

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Former PhD student Cameron Mackie will been awarded not one, but two dissertation prizes for his thesis on the aromatic universe. His work could provide us with a virtual sniff of space. ‘These molecules in space likely smell like a big charcoal grill!’

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An international team of astronomers, led by Will Rocha of Leiden Observatory, using the NASA/ESA/CSA James Webb Space Telescope have discovered that the key ingredients for making potentially habitable worlds are present in early-stage protostars, where planets have not yet formed.

An international team of astronomers including Leiden professor Ewine van Dishoeck has observed the benzene molecule (C6H6) in a planet-forming disk around a young star for the first time. The observations tell us more about the forming of planets in this disc, like our own Earth. The scientists publish…

Twee teams of astronomers, including from the universities of Amsterdam and Leiden, have discovered how hot gas giants are surrounded by large halos of thin helium gas, an indication that they are slowly losing their atmosphere. The helium, that was recently seen for the first time by the Hubble space…

Galaxy intrinsic alignments induce a major astrophysical contamination to weak gravitational lensing measurements and need to be modelled and mitigated when extracting cosmological information from such measurements.

The Old Observatory is located on the grounds of the Hortus. This is the oldest surviving university observatory in the world. Since 1633, the University of Leiden has used the various rooms for the education of students. The Visitor Center on the ground floor of the Old Observatory is part of the Hortus…

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The cosmology research line focuses on the theory of inflation in order to embed it in the microscopic theories of supergravity and string theory.

In this thesis we push the boundaries of high-resolution imaging at radio frequencies between 100 and 200 MHz. Using the International LOFAR Telescope that spans across Europe we achieve sub-arcsecond angular resolution.

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An international team led by astronomers at Leiden University has shown in laboratory experiments that sulfur can bind with ammonium under icy cosmic conditions and form a salt that sticks to dust and pebbles. The resulting sulfur salt not only helps to explain the mystery of the missing sulfur gas,…

The Royal Netherlands Academy of Sciences (KNAW) has awarded an Academy Professorship to Ewine van Dishoeck, Professor of Molecular Astrophysics at Leiden University.

A team of scientists, including Leiden Astronomer Alice Booth, has discovered silicon monosulfide molecules in the dust disk around a young star. Such molecules indicate planet formation. The team made the discovery using the ALMA telescopes. This method provides an alternative when direct observation…

A team of international researchers led by Tomas Stolker in the Netherlands has imaged a young gas giant exoplanet near a 12-million-year-old star. The planet is orbiting a star at which planet formation has finished, while the same-aged companion star still has a planet-forming disk. The researchers…

Smart algorithms and powerful processors are just as essential for astronomy as big telescopes. Astronomers at Leiden University therefore constantly operate at the interface between astronomy and data science.

Whether finding signals of dark matter or discovering hydrogen in the vicinity of exoplanets, Leiden astronomers are world players in their field, and they are part of a long tradition: Leiden was the first university in the world to have its own observatory.

In addition to the walk-in tours at the visitor center, we also offer private tours for groups. These tours delve deeper into the history of the building, but also offer the opportunity to learn more about astronomy in general.