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Hans Sigrist Prize for astronomer Ignas Snellen

On Saturday 7 December, Leiden professor of Observational Astrophysics Ignas Snellen received the Hans Sigrist Prize from the University of Bern. The prize was awarded to him for his groundbreaking research on planets outside our own solar system.


The prize consists of 100,000 Swiss francs and is intended for scientists who are at mid-career, and who are expected to make more significant contributions to their field. Snellen received the prize during the Dies Natalis of the Swiss university.

Ignas Snellen receives the prize in Bern

More and more exoplanets

He was also invited to speak at a symposium, where he told his audience about the history and future of exoplanet research. In the last two decades, he said, the number of known exoplanets has risen from a handful to more than 4,000. More planet discoveries are to be expected, said Snellen, and more and more will be discovered about the properties of these exoplanets.

Is there life out there?

In his own research, Snellen tries to fathom the composition of the atmospheres around exoplanets. Most exoplanets cannot be observed directly since they are extremely far away and do not emit light themselves. That is why Snellen uses indirect observations of these planets, based on observations of the star which the exoplanets orbit around. When an exoplanet passes in front of this star, the strength and composition of the star’s light temporarily change. The chemical elements in the atmosphere of the exoplanet then provide a very specific fingerprint. Snellen developed a method to identify the molecules, such as oxygen, in the atmospheres from these fingerprints. This work may also point out in the future on which planets outside our solar system life is possible.

Image credits: © University of Bern, Manu Friederich

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