In search of a new era of UK X-ray astronomy

X-ray astronomy is our gateway to the hot universe. More than half of the baryons in the cosmos are too hot to be visible at shorter wavelengths. Studying the extreme environments of black hole and neutron star vicinities also requires X-ray data. With the successful launch of India's AstroSat in 2015, and the few – but transformative – results from Japan's short-lived Hitomi mission in 2016, a new window has been opened into high-sensitivity fast timing and high X-ray spectral resolution. Together with the all-sky survey missions expected soon, X-ray astronomy is now exploring new parameter space.