2004BaltA..13..505J

We have studied a sample of very young (1-5 Myr) bona fide and candidate brown dwarfs in the ChaI star-forming cloud in terms of their kinematic properties, the occurrence of multiple systems among them as well as their rotational characteristics. Based on high-resolution spectra taken with UVES at the VLT (8.2 m), a radial velocity (RV) survey for close planetary or brown dwarf companions to the targets was carried out. No RV variability has been found hinting at a low multiplicity fraction. Upper limits for the mass M₂ sin i of possible companions range between 0.1 M_Jup and 2 M_Jup. Furthermore, the dispersion of the mean RVs of the sample was found to be only 2.2 km.s^–1 setting an empirical upper limit for possible ejection velocities. Finally, we have found that the brown dwarfs in Cha I are moderately fast rotators with projected rotational velocities v sin i of 8-26 km.s^–1 and rotational periods of 2 to 3 days.