Doppler CORALIE measurements of the solar-type stars HD 141937 , HD 162020 , HD 168443 and HD 202206 show Keplerian radial-velocity variations revealing the presence of 4 new companions with minimum masses close to the planet/brown-dwarf transition , namely with m _ { 2 } \sin { i } = 9.7 , 14.4 , 16.9 , and 17.5 M _ { Jup } , respectively .
The orbits present fairly large eccentricities ( 0.22 \leq e \leq 0.43 ) .
Except for HD 162020 , the parent stars are metal rich compared to the Sun , as are most of the detected extra-solar planet hosts .
Considerations of tidal dissipation in the short-period HD 162020 system points towards a brown-dwarf nature for the low-mass companion . HD 168443 is a multiple system with two low-mass companions being either brown dwarfs or formed simultaneously in the protoplanetary disks as superplanets .
For HD 202206 , the radial velocities show an additional drift revealing a further outer companion , the nature of which is still unknown .
Finally , the stellar-host and orbital properties of massive planets are examined in comparison to lighter exoplanets .
Observed trends include the need of metal-rich stars to form massive exoplanets and the lack of short periods for massive planets .
If confirmed with improved statistics , these features may provide constraints for the migration scenario .