Beta Cygni

Beta Cygni is a binary star system in the Milky Way. It consists, like most binary star systems, of a dwarf and a yellow giant star. Due to its distance, it is hard to guess the age of the system, although it is thought to be younger than our solar system.

Beta Cygni, like many stars, was known since man had first looked up at the skies. Even so, its distance from Earth makes it difficult to get a clear image of either star. The main star appears as a colourful blur; the companion appears as a brown disc. Both are estimated to be smaller than the Sun due to their feeble energy.

Beta Cygni A
Beta Cygni A, the yellow giant star, is small even for a giant star, being "only" 69 times the radius of the Sun. Beta Cygni A is estimated to be more massive, similar to the fact that the Sun is more massive than the slightly larger Alpha Centauri A. Beta Cygni is estimated to be burning the last of its hydrogen fuel and is on its way from expanding from a yellow giant to a red giant.

Beta Cygni B
Beta Cygni B, the orbiting blue main sequence star, is the smallest star known, slightly smaller than the planet Venus. Like most subdwarf stars, Beta Cygni B is slightly elliptical, as opposed to most stars, in the shape of near-perfect spheres