Detecting optical counterparts to gravitational-wave events with GOTO and developing techniques to enable accurate measurements of gravitational waves

Detecting optical counterparts to gravitational-wave events with GOTO and developing techniques to enable accurate measurements of gravitational waves detected by either LIGO or LISA To date 90 gravitational-wave events have been observed with the ground-based detector, e.g., LIGO, Virgo and KAGRA. All these events have been due to the merger of black holes and neutron stars. GW170817 was the first, and only event so far, that has allowed us to perform multi- messenger astrophysics; GW170817 was seen in both the gravitational-wave and electromagnetic spectrum. With joint observations we have been able to understand so much more than with either messenger alone, such as the origin of exotic materials and developing an independent way to measure the Hubble constant. The next LIGO-Virgo-KAGRA observing run (O4) starts in May 2023 until the end of 2024, where we expect to see new events every few days, including, hopefully, more gravitational-wave events with an observable electromagnetic counterpart. Looking to the future, the space detector LISA is due to be launched in the mid 2030s and it will probe a different part of the gravitational-wave spectrum to ground based detectors. In this regime, we will be able to detect, for example, supermassive black hole mergers. The time is now to start developing the techniques to make sure we can detect these systems and potentially enable conventional telescopes to capture any resulting electromagnetic counterpart.