Einstein Probe: Exploring the ever-changing X-ray Universe

The Einstein Probe is a small mission dedicated to time-domain astronomyto monitor the sky in the soft X-ray band (0.5–4 keV). It will carry out systematic survey and characterisation of high-energy transients at unprecedented sensitivity, spatial resolution, Grasp and monitoring cadence. Its wide-field imaging capability, as provided by an X-ray monitor with a fieldof viewof 3600 square degrees, is enabled by using established technology of micro-pore lobster-eye focusing optics. Complementary to this wide-field instrument is a follow-up X-ray telescopewith a large effective area and a narrow fieldof view. It is also capable of real time triggering and downlink of transient alerts on the fly, in order to activate multi-wavelength follow-up observations by other astronomical facilities worldwide. Its scientific goals are concerned with discovering new or rare types of transients, particularly tidal disruption events, supernova shock breakouts, high-redshift gamma-ray burstsand, particularly, electromagnetic sources associated with gravitational wave events. The mission is planned for launch around end of 2022, with a lifetime of three years and five years as a goal.