Astrophysics (Index)About

instability region

(region around an object where orbits cannot persist)

The term instability region is used for a region (range of radii) around an astronomical body where an orbit around it would be unstable due to one or more additional orbiting bodies. The term is particularly used for a region surrounding multiple bodies in orbit, such as a binary star in a fairly close orbit: within a region close to the pair, a planet orbiting the pair would pass close enough to one to significantly affect its orbit.

Further reading: