Direct imaging of planets and brown dwarfs around young stars

R. Neuhaeuser (1), E. Guenther (2), M. Mugrauer (1)

(1) AIU, University Jena, Germany, rne@astro.uni-jena.de
(2) TLS, Tautenburg, Germany,

We will present and discuss recent results on direct imaging searches
for sub-stellar companions around young nearby stars, i.e. both
young brown dwarfs and young planets in orbit around young stars.
Some of the previously found young brown dwarf companions are
found around binary stars, e.g. TWA-5, a spectroscopic binary.
And some of the young brown dwarfs found as companions are binary
themselves, such as the brown dwarf companions B ad C of HD 130948.
We will present our recent new evidence for a third object in the
GQ Lupi system, a classical T Tauri star with a very low-mass sub-stellar
companion, which is most certainly a planet detected directly.
We will discuss the distribution of mass ratio in systems made out
of a star and brown dwarf companion and discuss the relevance
of mass ratio for the disputed definition of planets.