Constraints on the companion masses of the target sample. Open squares show the minimum companion mass M₂ sin i derived from radial velocities. Blue filled circles indicate the formal companion masses M₂ derived from astrometry for orbits with >2σ-significance. Grey-shaded areas show the companion mass interval constrained by astrometry. The vertical dashed line indicates the adopted threshold mass of 80 M_J between brown dwarfs and stars. Twelve systems could not be constrained by Hipparcos astrometry, either because the derived mass limit was very high (>0.63 M_⊙) or because the orbital period was not covered by Hipparcos measurements.