A binary system is an astronomical term referring to two objects in space (usually stars, but also planets, galaxies or asteroids) which are so close that their gravitational interaction causes them to orbit about a common center of mass. Some definitions (e.g. that of double planet, but not that of binary star) require that this center of mass is not located within the interior of either object. A multiple system is like a binary system but consists of three or more objects.
In popular culture
Binary suns and star systems feature heavily in Star Wars, especially Revenge of the Sith and A New Hope. In the Discovery program Alien Planet, the planet Darwin IV orbits a binary system.
References
- Astronomy: A Visual Guide by Mark A. Garlick
