Research project Gravity Meets Light
When neutron stars collide they create both light and gravitational waves. Researchers at Stockholm University are studying these collisions in the hope they will find the answer to fundamental questions – such as how the heaviest elements are formed, and how fast the universe is expanding.

A neutron star is the ultra-dense collapsed core of an exploded star. They weigh about the same as our sun, but are a mere 20 kilometers across. Gravity at the surface of a neutron star is two hundred billion times stronger than that on Earth.
Binary neutron stars orbiting each other spiral inward by generating gravitational waves, which spread out into space. Finally, they crash into one another, combining to form a single neutron star which in many cases will soon collapse to a black hole. The collision produces copious quantities of heavy, radioactive matter, which is expelled into space, rendering the collision visible as a burst of electromagnetic radiation. A collision of this kind is called a kilonova, or macronova.
The Gravity Meets Light project is aimed at connecting diverse and complementary expertise across departments at SU, covering the entire chain of the kilonova event – from modelling the beginning of inspiral, through merger and nucleosynthesis, to light curve and spectral appearance. Finally - the project looks to determine the role and use of these exotic transients for cosmology.
Project members
Project managers
Stephan Rosswog
Professor

Anders Jerkstrand
Senior Researcher

Members
Anders Jerkstrand
Senior Researcher

Jesper Sollerman
Professor
Hiranya Peiris
Professor

Ariel Marcelo Goobar
Professor
