Caption: A diagram of illustrating binary stars and binary orbits (FK-435).

Note there many kinds of binaries in astronomy: binary asteroids, binary black holes, binary neutron stars, binary planets, binary pulsars, binary stars, binary trans-Neptunian ojects, X-ray binaries, etc.

All ideal binaries are gravitational two-body systems which have orbits like those illustrated in the diagram.

Credit/Permission: © David Jeffery, 2005 / Own work.
Image link: Itself.
Local file: local link: binary_orbit.html.
File: Star diagram file: binary_orbit.html.