Alpha Centauri B

Alpha Centauri B is part of the Alpha Centauri star system, located approximately 4.37 light-years from Earth, making it the nearest star system to our Solar System. The system is visible from the Southern Hemisphere as part of the constellation Centaurus.

Alpha Centauri B is a K-type main-sequence star (spectral type K1V), meaning it is slightly smaller and cooler than the Sun. It orbits around a common center of mass with Alpha Centauri A, a Sun-like G-type star, with an orbital period of approximately 80 years.

A candidate planet known as Alpha Centauri Bb was announced in 2012 as orbiting Alpha Centauri B, but its existence has been heavily disputed, and subsequent analyses have questioned the original detection method. The question of whether planets exist in the Alpha Centauri system remains one of the most actively investigated topics in astronomy, given the system's proximity to Earth.

The habitable zone of Alpha Centauri B—the region where liquid water could exist on a planet's surface—is estimated to be closer to the star than the Sun's habitable zone, due to the star's lower luminosity. However, the gravitational influence of Alpha Centauri A in the binary system complicates the long-term orbital stability of planets within that zone.