Large-Scale Distribution of Young Nearby Stars

Ralph Neuhaeuser 
IfA Honolulu and MPE Garching

With optical follow-up observations of unidentified ROSAT
X-ray sources, many new young stars have been found, from
very young pre-main sequence stars to 100 Myrs old zero-age
main sequence stars. These young stars are found not only
on star forming dark clouds, but also around the clouds.
Different formation scenarios will be discussed: Isolated 
formation, ejection from clouds, and the link to the Gould Belt.
These new young stars do include pre-main sequence stars
within 100 pc, well suited for high dynamic range imaging
in the search for sub-stellar companions.
Among ROSAT sources, we also identified young brown dwarfs.