companion An object, that may be a star, a brown dwarf, or a planet, in orbit around a brighter star. In a binary star system, it is the fainter of the two components. A companion may be detected directly (i.e., visually), or indirectly (see companion, unseen). Related category • TYPES OF STAR Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |