The observational signatures of nascent neutron stars

Neutron stars are the remnants of some of the most massive explosions in the Universe. These exotic objects, with masses larger than the Sun confined to the size of a small city, offer a laboratory to study fundamental physics in conditions unlike any other in the Universe, and impossible to achieve on Earth. In this thesis, I show how observations of massive explosions in the Universe can probe the birth of these exotic objects and provide insights into the lives and deaths of stars more massive than the Sun, the evolution of our Universe and the behaviour of nuclear matter.