"binary star." YourDictionary, n.d. Web. 06 December 2018. <https://www.yourdictionary.com/binary-star>.
binary star. (n.d.). Retrieved December 06th, 2018, from https://www.yourdictionary.com/binary-star
A system of two stars that orbit a common center of mass, appearing as a single star when visible to the unaided eye. The orbital periods of binary stars range from several hours to several centuries. By some estimates, at least half of the stars in the Milky Way galaxy are members of binary star systems. Also called double star