Your guide to the Solar System and the night sky
🌎 Location: Greenwich, United Kingdom [change]

Alioth - ε Ursae Majoris (epsilon Ursae Majoris)

Alioth, also designated as ε Ursae Majoris (epsilon Ursae Majoris), is a variable hypergiant star in the constellation of Ursa Major.

Alioth visual magnitude is 1.77, making it the 31th brightest star in the sky. Thanks to its high brightness, Alioth is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.

The table below summarizes the key facts about Alioth:

1.77
Hypergiant
Alioth - ε Ursae Majoris (epsilon Ursae Majoris) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 69°.

Celestial coordinates and finder chart of Alioth

Alioth is situated north of the celestial equator, as such, it is more easily visible from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Alioth are provided in the following table:

12h 54m 01s
+55° 57’ 34”
122.18°
61.16°
Ursa Major

The simplified sky map below shows the position of Alioth in the sky:

Finder chart Alioth - ε Ursae Majoris (epsilon Ursae Majoris) star
Simplified finder chart for Alioth - ε Ursae Majoris (epsilon Ursae Majoris).

Visibility of Alioth from your location

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Alioth - ε Ursae Majoris (epsilon Ursae Majoris) is circumpolar and transits at 15:19 UTC (altitude: 85.5°)

Digitized Sky Survey image of Alioth

The image below is a photograph of Alioth from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of Alioth is 0.112 arcsec per year in Right Ascension and -0.006 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of Alioth - ε Ursae Majoris (epsilon Ursae Majoris) star
DSS2 image of Alioth. The red arrow shows the motion of Alioth during the next 1000 years (1.87 arcmin in Right Ascension and -0.10 arcmin in declination);

Distance of Alioth from the Sun and relative movement

Alioth is distant 80.89 light years from the Sun and it is moving towards the Sun at the speed of 9 kilometers per second.

24.81 pc
80.89 ly
-9 km/s
0.112 arcsec/year
-0.006 arcsec/year

Spectral properties of Alioth

Alioth belongs to spectral class A0 Alioth is also a Cr chemically peculiar star.

-0.20
A0
10382K

The red dot in the diagram below shows where Alioth is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of Alioth. Attribution: Richard Powell / CC BY-SA

Alternative designations of Alioth

Alioth
ε Ursae Majoris
(epsilon Ursae Majoris)
77 Ursae Majoris
SAO28553
SAO28553