“When people think of an astronomer, they often imagine a passionate scientist, peering through his telescope, unravelling the secrets of the infinite space,” says Gijs Nelemans with a laugh. “Pure romance. The reality is that I direct my gaze at the starry sky through a computer screen. And that starry sky I look at is made up of data that I interpret.”
Gijs Nelemans comes from a 'teaching nest,' and physics was his favourite subject in high school. “I saw a career as a physics teacher as very appealing. After high school, I went to the university in Utrecht. There, I pursued a combined study of physics and astronomy. Soon, I found astronomy much more interesting.”
Unknown and Exciting Territory
“Astronomy is the application of physics in space. In physics, we already know a lot. And what we suspect and want to prove can typically be investigated in a controlled environment through experiments,” explains Nelemans.
“In astronomy, there is a lot we don't know. It's precisely this aspect that makes it exciting for me. You are stepping over a boundary in knowledge, working in unknown territory.”
Research on Binary Stars
After his Master's in Utrecht, Gijs Nelemans completed his PhD in Amsterdam, followed by a postdoc in Cambridge and at Radboud University. He has been working here since 2006. In 2017, he was appointed Professor of Gravitational Wave Astrophysics.
“I research binary stars. A binary star consists of two stars that orbit around a single centre of gravity. There are countless binary stars in the universe. Not all these stars are the same. By comparing them, we want to chart the evolution of these stars – how they form, how they exchange mass, what that does to the environment, and how they sometimes explode.”
Building Computer Models
“I haven't looked through a telescope in years,” says Gijs Nelemans. “For my research, I use data from scientists who do collect data through telescopic observations. This data forms the basis for building computer models. Through such a model, you try to find out what you don't yet know.”
The European LISA Project
In astronomy, very finely tuned equipment measures what happens in space, for example, through light and radio waves.
“In the LISA project, we will also collect information, but in a completely different way. From space, we will measure so-called gravitational waves, allowing us to study many objects, including binary stars, uniquely. This can be beautifully used to test the models.”
Making New Discoveries
LISA is a European project. The acronym stands for Laser Interferometer Space Antenna. “From 2035, three spacecraft will fly around the sun, trailing behind Earth. By continuously measuring their distances from each other with laser beams, they will capture gravitational waves from the universe. It's a new technique. With LISA, we expect to make many new discoveries.”
Scientific Research
Gijs Nelemans is one of the coordinators in Europe, reaching out to scientists to participate in the project. What we concretely gain from LISA is a question he often gets.
“It’s purely scientific, discovering what you don’t yet know. At the same time, it’s a huge challenge for technological companies to design and build such spacecraft. These technologies will eventually find their applications in other fields.”
