New generation sky surveys, exotic transients and gravitational wave sources

Stellar mergers and explosions create the heavy elements we see in the entire visible Universe. Supernovae come from the deaths of massive stars and (at least some) from the merger of white dwarfs.

While stars evolve over millions or billions of years, a supernova explosion happens in seconds and the glowing remnant lasts for years.

We aim to understand how these explosions happen and how they create the neutron stars, pulsars and black holes in our galaxy.

But we have recently seen that even when a neutron star is formed after the brief live of a massive star, that is not the end of the stars explosive existence. If they come in close binary pairs then they can merge, with spectacular results.

In 2017 a breakthrough discovery was made when the first electromagnetic counterpart to a gravitational wave source was found.

Termed a 'kilonova', this was the result of a pair of merging neutron stars and the optical and infrared light arose from the radioactive decay of heavy elements (which we call r-process elements). These elements are heavier than iron and such neutron star mergers may be responsible for all these heavy elements.

Our projects will find more of these, and the combination of gravitational waves and electromagnetic signals opens up a new window on the Universe.