eROSITA is the primary instrument on the Russian "Spectrum-Roentgen-Gamma" (SRG) satellite scheduled to be launched in autumn 2018/spring 2019.
Over a period of four years eROSITA will perform an imaging all-sky survey in X-rays at 0.3 - 10.0 keV energies that is expected to detect more than half a million stars and stellar systems.
The survey phase will be followed by a pointed observations phase with a nominal duration of three years.
Science overview: eROSITA Science Book
The Hamburg observatory is leading the stellar working group of the German eROSITA consortium
(Chairs: J. Schmitt & J. Robrade).
Time domain: eROSITA: stellar variability
All-sky survey - stellar content: Stellar surface densities at var. galactic locations
Source detection and catalogues: Energy bands for stars