(ME-rak )

Beta Ursae Majoris


Distance (Light Years) 79.4 ± 1.2
Apparent Magnitude 2.34
Color (B-V)-0.02

Names For This Star

The name Merak derives from the Arabic name Al Marakk meaning "The Loin", that is, "The Loin of the Bear". "Mirak" is an alternative spelling.

Description of the Star

Merak is a white A1V main sequence star almost 60 times as luminous as the sun. The spectral type implies a mass about three times that of the sun, a diameter more than twice that of the sun, and an effective temperature of 9600 K.

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


48 Ursae Majoris

Hipparcos Identifier (HIP Number)


Harvard Revised (HR Number)


Henry Draper Catalog (HD Number)


Bonner Durchmusterung (BD Number)

BD+57 1302
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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