Einstein Probe

The Wide-field X-ray Telescope uses lobster-eyelobster-eye opticsArrays of tiny square channels on a spherical surface that focus soft X-rays by grazing reflection, as a lobster's eye focuses light. They trade PSF quality for a very wide field of view, suited to monitoring. micropore optics in 12 modules to image about 3,600 deg²square degreeUnit of solid angle: one degree by one degree on the sky. The whole sky is about 41,253 deg²; the full Moon covers about 0.2 deg². at once at 0.5–4 keVelectronvoltThe energy an electron gains across 1 volt, 1.602 × 10⁻¹⁹ J. High-energy astronomy labels photons by energy: optical light is about 1.7–3.1 eV, X-rays 0.1–100 keV, gamma rays from about 100 keV to beyond 100 TeV. A 1 keV photon has wavelength 1.24 nm.; the Follow-up X-ray Telescope, two Wolter-Igrazing-incidence opticsX-rays reflect only at angles of a degree or less, so X-ray telescopes use nested shells of paraboloid and hyperboloid mirrors seen almost edge-on (the Wolter-I design). More shells add effective area; figure accuracy sets the PSF. modules with pnCCD cameras, refines positions and spectra at 0.5–10 keV. Built for soft X-rayhard X-raysThe higher-energy end of the X-ray band, conventionally above about 10 keV; soft X-rays are below about 2 keV. Hard X-rays penetrate absorbing gas, so they reveal obscured black holes. transientstime-domain astronomyStudying how sources vary or appear over time: supernovae, tidal disruptions, flares, variable stars and moving objects. Needs wide fields, high cadence and fast data processing.: fast X-ray transients, tidal disruptions, stellar flares and counterparts of gravitational-wave events. A CAS mission with ESA, MPE and CNES.

Operator

CAS, ESA, MPE

Orbit

Low Earth orbit

WXT

0.5 keV – 4 keV

FXT

0.5 keV – 10 keV

Launch

9 January 2024