Neutron star mergers and the high-density equation of state

In August 2017 the LIGO-Virgo network detected for the first time gravitational waves from a neutron star merger. The event, dubbed GW170817, was followed by electromagnetic radiation. Various emission mechanisms produced radiation at different wavelengths throughout the electromagnetic spectrum from gamma rays to radio. The gravitational and electromagnetic radiation has provided a wealth of information on the physics of neutron star mergers. In particular, it was possible to infer constraints on stellar properties of neutron stars and the only incompletely known equation of state of high-density matter. Specifically, bounds on neutron star radii have been derived from this very first observation of a neutron star merger. Future detections with increased sensitivity promise accurate and robust measurements of neutron star properties and thus to elucidate properties of high-density matter.