Zeta Ursae Majoris B

Alcor

Ursa Major

3.99
Apparent Mag
81.7
Distance (ly)
A5V
Spectral Type
8,000
Temperature (K)

Alcor is the fainter companion to Mizar, together forming one of the most famous visual pairs.

Stellar Data

Apparent Magnitude3.99
Absolute Magnitude2
Distance81.7 light-years
Spectral TypeA5V
Temperature8,000 K
Luminosity10 L☉
Radius1.84 R☉
Mass1.8 M☉
Right Ascension13h 25m 13.5s
Declination+54° 59′ 16.7″
ConstellationUrsa Major

Notable Facts

  • Seeing Alcor next to Mizar was an ancient eye test
  • Alcor and Mizar form a sextuple star system
  • Also known as the Horse and Rider

More Stars in Ursa Major

View constellation