Binary stars are captivating celestial systems where two stars are gravitationally bound, orbiting a common center of mass. This intricate cosmic dance...
A binary star system consists of two stars orbiting a shared gravitational center of mass, unlike optical doubles which merely appear close from Earth without being gravitationally linked.
Binary and multiple-star systems are incredibly common; it's estimated that over half, and potentially up to 85%, of all stars exist within such systems, rather than as solitary stars like our Sun.
Binary stars are primarily classified by their observation method: visual binaries (seen separately), spectroscopic binaries (detected by spectral shifts), eclipsing binaries (one star blocks the other's light), and astrometric binaries (detected by a star's wobble).
Studying binary stars allows astronomers to accurately determine stellar masses and radii, test theories of stellar evolution and gravity, and understand processes like mass transfer, which can lead to phenomena such as supernovae.