<P> Alnitak (ζ Orionis) is a triple star system at the eastern end of Orion's belt and is 817 light - years from the Earth . Alnitak B is a 4th - magnitude B - type star which orbits Alnitak A every 1,500 years . The primary (Alnitak A) is itself a close binary, comprising Alnitak Aa (a blue supergiant of spectral type O9. 7 Ibe and an apparent magnitude of 2.0) and Alnitak Ab (a blue dwarf of spectral type O9V and an apparent magnitude of about 4). Alnitak Aa is estimated as being up to 28 times as massive as the Sun, and to have a diameter 20 times greater . It is the brightest star of class O in the night sky . </P> <P> Alnilam (ε Orionis) is a supergiant, approximately 1,340 light - years away from Earth and magnitude 1.70 . It is the 29th - brightest star in the sky and the fourth - brightest in Orion . It is 375,000 times more luminous than the Sun . Its spectrum serves as one of the stable anchor points by which other stars are classified . </P> <P> Mintaka (δ Orionis) is 915 light - years away and shines with magnitude 2.21 . Mintaka is 90,000 times more luminous than the Sun . Mintaka is a double star . The two stars orbit around each other every 5.73 days . </P> <P> Richard Hinckley Allen lists many folk names for the Belt of Orion . English ones include: Jacob's Rod or Jacob's Staff; Peter's Staff; the Golden Yard - arm; The L, or Ell; The Ell and Yard; the Yard - stick, and the Yard - wand; the Ellwand; Our Lady's Wand; the Magi / the Three Kings; the Three Marys; or simply the Three Stars . </P>

What does it mean when 3 stars are in a row