Binary star
Videos
A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars are among the most important objects in astrophysics because
The nearest binary star Alpha Centauri, as photographed by the Hubble Space Telescope
Edge-on disc of gas and dust present around the binary star system HD 106906
Artist's conception of a cataclysmic variable system
Artist's impression of the binary star system AR Scorpii
Double star
Videos
In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes.
The Hubble Telescope's 100,000th capture showing two stars that appear close together. The star on the right is a nearby Milky Way star while the star to the left is a quasar 9 billion light years away. This is an example of an optical double and is due to the quasar's immense luminosity.
Astronomers have mistakenly reported observations of a double star in place of J 900 and a faint star in the constellation of Gemini.
The color-contrastant binary Gamma Andromedae seen by a telescope