Epsilon Ursae Majoris


Distance (Light Years) 80.9 ± 1.2
Apparent Magnitude 1.76
Color (B-V)-0.02

Names For This Star

According to Allen, the first usage of the name "Alioth" for this star was in the Alfonsine Tables published in Spain in 1252 under the patronage of King Alfonso X of Leon and Castile. The only etymology offered is the name may originate with the word Alyat meaning "The Fat Tail of the Eastern Sheep". This derivation is unlikely.

A variant spelling is "Aliath."

Description of the Star

Alioth is a white star of spectral type A0pCr. The spectrum of the star is characterized by abnormally strong lines of chromium and europium (Burnham). The diameter of the star is given in the The Bright Star Catalog as 4 times that of the sun.

According to Burnham, Alioth is part of a star cluster including at least 16 other stars from the Ursa Major area of the sky, as well as Mizar, Merak, Alcor, 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


77 Ursae Majoris

Hipparcos Identifier (HIP Number)


Harvard Revised (HR Number)


Henry Draper Catalog (HD Number)


Bonner Durchmusterung (BD Number)

BD+56 1627
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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