  We report the discovery of a 16-20 Jupiter mass radial velocity companion
around the very young (3 Myr) brown dwarf candidate ChaHa8. Based on
high-resolution echelle spectra of ChaHa8 taken between 2000 and 2007 with UVES
at the VLT, a companion was detected through RV variability with a
semi-amplitude of 1.6 km/s. A Kepler fit to the data yields an orbital period
of the companion of 1590 days and an eccentricity of e=0.49. A companion
minimum mass M2sin i between 16 and 20 Jupiter masses is derived when using
model-dependent mass estimates for the primary. The mass ratio M2/M1 might be
as small as 0.2 and, with a probability of 87%, it is less than 0.4. ChaHa8
harbors most certainly the lowest mass companion detected so far in a close (~1
AU) orbit around a brown dwarf or very low-mass star. From the uncertainty in
the orbit solution, it cannot completely be ruled out that the companion has a
mass in the planetary regime. Its discovery is in any case an important step
towards RV planet detections around BDs. Further, ChaHa8 is the fourth known
spectroscopic brown dwarf or very low-mass binary system with an RV orbit
solution and the second known very young one.
