These astronomical objects are classified in one or more of four types: astrometric, spectroscopic, visual, and eclipsing.
A cataclysmic variable is one of these in which luminosity is variable due to accretion, until the system destroys itself. The orbits of these objects are observed to decay in a manner consistent with the existence of gravitational waves, which is a proof of general relativity, and the region of space in which a mass is bound to one of the component stars of this is known as the Roche lobe. These astronomical objects are classified in one or more of four types: astrometric, spectroscopic, visual, and eclipsing. For 10 points, name the astronomical systems, of which Sirius is an example, that consist of two stars in orbit about each other.
A cataclysmic variable is one of these in which luminosity is variable due to accretion, until the system destroys itself.
{binary} star systems [or {binary} stars or {binaries}]