80 Ursae Majoris


Distance (Light Years) 81.2 ± 1.2
Apparent Magnitude 3.99
Color (B-V)0.16

Description of the Star

Alcor is a hot, white A5V main sequence star having a luminosity about 13 times that of the sun.

The spectral type implies that Alcor has an effective temperature of 8500 K, a diameter 1.7 times that of the sun, and a mass of about 2.2 solar masses.

Alcor is a variable star of Delta Scuti type; see Caph.

The Ursa Major Cluster

According to Burnham, Alcor is part of a star cluster including at least 16 other stars from the Ursa Major area of the sky, as well as Alioth, Merak, Mizar, Phecda, and Megrez in the Big Dipper. The Ursa Major cluster represents an ellipsoidal volume of space about 30 ly long by 18 ly in width.

Other Designations For This Star


80 Ursae Majoris

Hipparcos Identifier (HIP Number)


Harvard Revised (HR Number)


Henry Draper Catalog (HD Number)


Bonner Durchmusterung (BD Number)

BD+55 1603
Smithsonian Astrophysical
Observatory compendium (SAO Number)

Fundamental Katalog (FK5 Number)



Copyright © 1998 - 2010 by Arnold V. Lesikar,
Professor Emeritus
Dept. of Physics, Astronomy, and Engineering Science,
St. Cloud State University,St. Cloud, MN 56301-4498

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