Description
Einstein Probe, launched in January 2024, is opening a new window on the transient X-ray Universe
through the wide-field capabilities of its Wide-field X-ray Telescope and the rapid, sensitive
follow-up provided by the Follow-up X-ray Telescope. In this talk, I will present the main characteristics
of the mission and its role in the discovery and characterization of X-ray transients, with
a focus on accreting compact objects. I will then discuss the synergy between Einstein Probe and
fast optical photometry, highlighting simultaneous Einstein Probe and TNG/SiFAP2 observations
of the accreting millisecond pulsar SAX J1808.4-3658 during its 2025 outburst. These data include
a thermonuclear burst observed simultaneously in X-rays and optical wavelengths, as well as coordinated
observations probing the connection between X-ray and optical pulsations across different
stages of the outburst.