Cataclysmic variable binary star. Computer illustration of a cataclysmic variable binary star system. A red dwarf (left) is seen in mutual orbit with a white dwarf (right). An accretion disc of material pulled from the red dwarf can be seen around th...

Illustration of two black holes orbiting each other in a combined accretion disc. Eventually the black holes will merge, an event that will produce gravitational waves. Gravitational waves are a prediction of Einstein's theory of general relativity. ...