Alpha Centauri b

Alpha Centauri b (or planet "b" of Alpha Centauri) may refer to:

Stars

 * alpha Centauri B (Toliman), the second largest star in the α Cen trinary system

Planets

 * alpha Centauri Ab, an unconfirmed candidate exoplanet orbiting the largest star in the α Cen trinary star system, Rigel Kentarus (α Cen A)
 * alpha Centauri Bb, a proposed exoplanet orbiting the second largest star in the α Cen trinary star system, Toliman (α Cen B)
 * alpha Centauri Cb, an exoplanet orbiting the smallest star in the α Cen trinary star system, Proxima (α Cen C)