Einstein Probe: Unveiling the Transient X-ray Universe

The Einstein Probe (EP), a Chinese-led international X-ray astronomy mission with key contributions from ESA, MPE, and CNES, is advancing time-domain astrophysics through its unprecedented wide-field soft X-ray monitoring capability to discover and characterize cosmic X-ray transients. Launched in January 2024, EP carries two complementary instruments: the Wide-field X-ray Telescope (WXT), which employs lobster-eye micro-pore optics to monitor approximately 11% of the sky with exceptional sensitivity, and the co-aligned Follow-up X-ray Telescope (FXT), which provides high-resolution imaging, spectroscopy, and timing observations for rapid follow-up studies. During more than two years of in-orbit operations, EP has detected over 230 X-ray transients, including Tidal Disruption Events (TDEs), gamma-ray bursts (GRBs), rare compact binary systems, and previously unknown types of transients, thereby opening a new observational window for high-energy time-domain astrophysics. Major scientific achievements include the first demonstration of lobster-eye micro-pore focusing X-ray imaging over an extremely large field of view, the discovery of an intermediate-mass black hole through a tidal disruption event, the detection of a high-redshift gamma-ray burst with complex soft X-ray precursor emission, the identification of a weakly relativistic jet associated with a type Ic-BL supernova, and the discovery of unusual X-ray transients that highlight previously unrecognized manifestations of stellar collapse and compact-object interactions. These discoveries provide new insights into some of the most energetic and rapidly evolving astrophysical phenomena, ranging from stellar explosions and relativistic jets to tidal disruption events and black-hole accretion. Enabled by its unique instrumentation, autonomous rapid-response capability, and extensive international collaboration, EP is expected to continue delivering major discoveries and to remain a major facility for time-domain and multi-messenger astrophysics.