Large pairs of planets thought to orbit each other without a star, do not exist after all. That conclude Leiden researchers, after extensive computer modelling and simulations. What the double dots seen by the James Webb Space Telescope are, remains a mystery.

How do you combine the growth of wind energy with the protection of vulnerable seabirds? With her master’s thesis on this delicate balance, Sofie Hajer won the 2025 Unilever Research Prize. Her work provides new insights into how ecology and policy can strengthen each other.

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…

Planets existing in other solar systems contain invaluable information about the origin of planets and life. PhD candidate Yapeng Zhang has studied their atmospheres by looking at their smallest parts: isotopes. With her research she hopes to discover what makes our own solar system unique.

On Prinsjesdag, 16 September 2025, the Faculty of Governance and Global Affairs (FGGA) opened the new faculty year with a reception at Wijnhaven. The opening was dedicated to the university’s lustrum theme: ‘Ahead of Time’.

Every Political Science master’s student at Leiden University completes their degree with thesis. The thesis provides students with the opportunity to pursue a topic of their choosing in depth and conduct independent research. It is a demanding task that requires dedication, attention to detail, and…

A time-lapse of the universe in more detail than ever before: that’s the aim of the NSF–DOE Vera C. Rubin Observatory in Chile, which will unveil its first images of the night sky on 23 June. Researchers at Leiden Observatory have played a major role in making it all possible.

The university is home to many pearls of research institutes that do not make the news every day. The Executive Board visited one such pearl, the Institute of Philosophy, on Tuesday 1 July. It resulted in an inspired conversation.

In the nationalist nineteenth century, people developed an interest in medieval language and literature. The study of medieval material in one’s own vernacular was thought to reveal a great national past. But why, then, was Old English studied by Germans, Danes, Italians and many other nationalities…

Dutch mosquitos are more resilient to saltwater than previously thought. Environmental scientist Sam Boerlijst discovered this during his PhD research at the Hortus botanicus. This knowledge is crucial for understanding how mosquito-borne disease transmission might change in the future.

Plants can’t run away from enemies. Still, it would like to keep life-threatening herbivores at a distance. This can be done with odours. Klaas Vrieling of the Institute of Biology Leiden found out with his team how plants change odour production to keep the munchers at a distance.

Lecture, Astronomy on Tap

Lecture, CMGI Brown Bag Seminar

Lecture, CMGI Brown Bag Seminar

Lecture, LUCIS Keynote

Lecture, CMGI Brown Bag Seminar

Lecture, Economic and Social History Brown Bag Seminar

Lecture, CMGI Brown Bag Seminar

Lecture, CMGI Brown Bag Seminar

‘We may have taken steps together, but there is still much to do in the fight against racism and discrimination’, says Annetje Ottow, President of Leiden University’s Executive Board. ‘We have to be aware of this and continue to focus on this difficult, uncomfortable and often confronting topic.’

How can we cooperate better as a Faculty? Both with each other and with the outside world. Around 70 students and staff discussed this during the latest strategy session in Corpus. Keynote Harry van Dorenmalen, former president of IBM Europe: 'You know best what this Faculty stands for and what it n…

A staggering 6.5 billion chicks are killed worldwide every year. These are generally male chicks that are of no economic value. In Ovo has developed technology that can quickly determine the sex of a chick, to ensure that only female chicks are hatched. The first 150,000 chicks have now hatched in this…

This week, around 1,200 brand new students from 68 different countries are getting to know each other and their new student city. Orientation Week Leiden (OWL) got off to a good start on sunny Lammermarkt, which was packed with enthusiastic internationals.

During the annual graduation ceremony, not only were the Bachelor's students in Political Science honoured, but also those students who had written exceptional theses. The thesis prizes reward work that excels in originality, social relevance and academic quality. This year's winners are Ronny Wijling…

The nominees for the IRO Thesis Prize 2025 and the Prof. Dr. J.Th.J. van den Berg-prijs 2025. Who authored the best thesis in Leiden University’s bachelor’s programme in Political Science?

From 13 to 16 July, Leiden will host the EuroScience Open Forum (ESOF), the largest multidisciplinary scientific conference in Europe. Lars van Doorn from Leiden Law School will give a presentation.

With a self-converted red camper van, biologists and twin brothers Kevin and Marvin Groen go on a nature adventure in Eastern Europe. Together, they search for wild animals, beautiful nature and places to sport. From a long search for a bear in the Slovakian wilderness to the discovery that pelicans…

In June 2024 the Faculty of Archaeology welcomed a new Assistant Professor. Dr Alejandra Roche Recinos, originally from Guatemala, will strengthen the Faculty’s expertise on the archaeology of Central America. ‘I want to explore the lesser known archaeology of Southern Guatemala.’

More than 700 visitors got to know the Science Faculty during the Leiden Science Family Day. People of all ages could enjoy fascinating experiments, tours, interesting lectures, spectacular nitrogen shows and various workshops. It was an informative day with many (future) scientists, amazement and,…

Prisoners who are visited regularly by family or friends are less likely to be reconvicted in the short term than inmates who rarely or never receive visits. Visits should therefore be encouraged and facilitated, according to PhD candidate Maria Berghuis, who will defend her doctoral thesis on 23 June…

The James Webb Space Telescope continues to surprise us with stunning pictures, but of what exactly? Astronomer Nienke van der Marel shows with three images how massive stars lead short but explosive lives.

Today, ESA’s Gaia mission releases its new treasure trove of data about our home galaxy. Astronomers, led by the Leiden astronomer Anthony Brown, describe strange ‘starquakes’, stellar DNA, asymmetric motions and other fascinating insights in this most detailed Milky Way survey to date.

De klimaattransitie is in volle gang: de vervuilende industrie moet plaatsmaken voor duurzame productiemethoden. Werknemers in deze industrie zullen hierdoor nieuwe banen moeten vinden. Dat zal niet iedereen lukken. Heb oog voor die groep, waarschuwt politiek econoom Lars van Doorn.

Leiden University will be conferring three honorary doctorates in its special anniversary year. They will be awarded to Eliot Higgins, truth finder and founder of Bellingcat, Bonnie Honig, expert in feminist theory and legal theory, and Kelly Chibale, professor of organic chemistry, who works on prevention…

Symposium

Bezoek

PhD defence

PhD defence

Lecture, LUCIS What's New?! Series

We should mention differences in skin colour to our children because only then can we talk openly about prejudice and racism – and how to prevent them. This is what Professor Judi Mesman says in her book ‘Opgroeien in kleur’ (Growing up in Colour), which offers advice to parents. ‘Why is there only…

Webinar

Webinar

Webinar

Lecture

Lecture

Lecture

Lecture, China Seminar

PhD defence

Migration, globalisation, technological developments, climate change: the greatest challenges of our time all affect our labour market. But how exactly? And can we influence this? Professor of Economics Olaf van Vliet regards it as his job to reveal how things really are. ‘That way, we can work on solutions…