Dr. Marie Cornelius talks about neutrinos and supernovae on a Danish astronomy podcast

Dr. Marie Cornelius, a postdoctoral researcher in our working group, was recently a guest on the Danish astronomy podcast RumSnak. In the episode "Ghost particles in gigantic star explosions", she talks about neutrinos and the important role they play in supernova explosions.

Neutrinos are electrically neutral particles with a very small mass. They interact only weakly with matter and can therefore pass through large amounts of matter almost unaffected, which has earned them the nickname ghost particles. One important step towards our current understanding of neutrinos came from observations of the Sun. For decades, experiments detected fewer neutrinos originating from the Sun than predicted. The solution to this so-called solar neutrino problem was the discovery that neutrinos can change their flavour as they travel. Since experiments at that time were mainly sensitive to one flavour, neutrinos changing into another flavour appeared to have disappeared.

The podcast then turns to the role of neutrinos in supernovae. A supernova is a powerful explosion that can occur when a massive star reaches the end of its life and its core collapses. Around 99 percent of the energy released during this process is carried away by neutrinos. Neutrinos not only provide a signal from the interior of the collapsing star, but also play an important role in the explosion itself. They provide the shock wave with the necessary energy and thereby help drive the explosion.

Direct observational data on supernova neutrinos is very limited. So far, neutrinos from a supernova have only been detected once. In 1987, around 30 neutrino events were observed from Supernova 1987A. Theoretical calculations and computer simulations are needed to understand in detail how neutrinos behave inside a supernova.

This theoretical approach is central to Cornelius’ research. She studies the behaviour of neutrinos in the dense environment of a supernova core. Under these conditions, neutrinos can interact with each other, which can affect how they change their flavour and ultimately the explosion itself. Cornelius investigates these flavour conversions and their possible implications for the supernova explosion.

The full 51-minute episode of RumSnak is available on YouTube. The podcast is in Danish and is intended for listeners interested in astronomy and space.