The early-proposed exoplanet-candidate was discovered in 1989, based
upon the radial velocity method, and its existence was confirmed in 1991.
Its early mass determination of 11 Jupiter masses was
small enough to be considered a planet, but subsequent observation
and analysis determine it to be more massive, likely 147 Jupiter
masses. The second small stellar companion was
discovered through direct imaging during follow-up observations
and also initially an exoplanet-candidate, but spectrography
and the likely mass that it implies suggest it is a star. It has
a large orbit, making direct imaging (and spectrography) of it
effective, while the earlier discovered companion is in a small
orbit, giving it a radial velocity cycle short enough for
practical detection.
Each of the companions is determined to be either a red dwarf or
a brown dwarf; the defined difference is whether the object ever
has or will experience hydrogen burning, but this is sometimes unclear:
the mass ranges of red and brown dwarfs overlap and some
spectral types can be either of the two. Also, the companions'
masses are not precisely known: only a calculated probability density function based
upon observable data.