Stellar seismology from space: The Evris experiment on board Mars 94

High precision photometry from space is the only technique to detect the nonradial oscillations of a significant set of stars with different masses, ages, angular momentum, chemical composition, as already observed for the Sun. During an observation run of several days, a reasonably small telescope (10 cm) will collect enough photons to detect periodic signals of relative amplitude as low as 10 ^–6, coherent over this period. The frequency resolution necessary to distinguish the rotational splitting (0.5 H) will be achieved in increasing the observation run to 20 days.