Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:49  
clear_day Transit: 12:56  
SunsetSet: 21:04 south
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All Constellations » Ursa Major » 

Alcor - 80 Ursae Majoris

Alcor, also designated as 80 Ursae Majoris , is a variable main-sequence star in the constellation of Ursa Major.

Alcor visual magnitude is 4.01. Because of its moderate brightness, Alcor should be easily visible from locations with dark skyes, while it can be barely visible, or not visible at all, from skyes affected by light pollution.

The table below summarizes the key facts about Alcor:

Alcor - 80 Ursae Majoris is above the horizon from Greenwich, United Kingdom edit_location_alt. Altitude: 20°.

Celestial coordinates and finder chart of Alcor

Alcor 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 Alcor are provided in the following table:

13h 25m 13s
+54° 59’ 17”
Ursa Major

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

Finder chart Alcor - 80 Ursae Majoris star
Simplified finder chart for Alcor - 80 Ursae Majoris.

Visibility of Alcor from your location

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

Alcor - 80 Ursae Majoris is circumpolar and transits at 20:44 UTC (altitude: 86.5°)

Digitized Sky Survey image of Alcor

The image below is a photograph of Alcor 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 Alcor is 0.118 arcsec per year in Right Ascension and -0.016 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of Alcor - 80 Ursae Majoris star
DSS2 image of Alcor. The red arrow shows the motion of Alcor during the next 1000 years (1.97 arcmin in Right Ascension and -0.27 arcmin in declination);

Distance of Alcor from the Sun and relative movement

Alcor is distant 81.11 light years from the Sun and it is moving towards the Sun at the speed of 9 kilometers per second.

24.88 pc
81.11 ly
-9 km/s
0.118 arcsec/year
-0.016 arcsec/year

Spectral properties of Alcor

Alcor belongs to spectral class A5 and has a luminosity class of V corresponding to a main-sequence star.


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

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

Alternative designations of Alcor

80 Ursae Majoris