unseen companion An object, such as an extrasolar planet, brown dwarf, low-luminosity star, or black hole, that is too dim or near to its primary to be imaged but the existence of which can be inferred by other means, such as Doppler spectroscopy, astrometry, or photometry. Related category EXTRASOLAR PLANETS AND SUBSTELLAR OBJECTS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |