Hipparcos and red dwarf populations

The European Space Agency's Hipparcos satellite, launched in August 1989, and operated until August 1993, sent back scientific data for about 36 months. The reduction of the first 18 months already shows that the target accuracy for the five astrometric parameters of each star (0.002 arcsec for the position and annual proper motion components, and for the parallax) and for the photometric data (a few milli-magnitudes) will be achieved or even exceeded for most of the 118 000 pre-selected programme stars. These preliminary results will be presented.The contents of the Hipparcos observing programme with respect to red stars and anticipated improvements in the study of red dwarfs will be underlined.