Alpha Centauri is the closest star system to the Sol Solar System, being 4.37 light-years from the Sun.[1]
Background[]
The system consists of three stars: Alpha Centauri A and Alpha Centauri B, which form the binary star Alpha Centauri AB, and a small and faint red dwarf, Alpha Centauri C (also named Proxima Centauri), which is loosely gravitationally bound and orbiting the other two at a current distance of about 13,000 astronomical units (0.21 ly).
Alpha Centauri A[]
Alpha Centauri A is the principal member, or primary, of the binary system, being slightly larger and more luminous than the Sun. It is a solar-like main-sequence star with a yellowish color, whose stellar classification is spectral type G2 V.
Alpha Centauri B[]
Alpha Centauri B is the companion star, or secondary of the binary system, and is slightly smaller and less luminous than the Sun. It is a main-sequence star of spectral type K1 V, making it more an orange color than the primary star.
Proxima Centauri[]
Proxima Centauri is of spectral class M6 Ve, a small main-sequence star (Type V).