A Orionis, or Betelgeuse, is a bright, yellowish-red star of varying magnitude (0.5 to 1.4, generally 0.9).
[3 Orionis or Regel is a 1st magnitude star.
Y Orionis or Bellatrix, and x Orionis are stars of the 2nd magnitude.
Three collinear stars ?', c and 3 Orionis constitute the "belt of Orion"; of these E, the central star, is of the ist magnitude, 3 of the 2nd, while Orionis is a fine double star, its components having magnitudes 2 and 6; there is also a faint companion of magnitude io.
A Orionis, very close to Orionis, is a very fine multiple star, described by Sir William Herschel as two sets of treble stars; more stars have been revealed by larger telescopes.