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:

Color of Alcor ⬤

Magnitude of Alcor 4.01

Class Main-sequence

VISIBILITY RIGHT NOW 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:

Right Ascension J2000 13h 25m 13s

Declination J2000 +54° 59’ 17”

Galactic Longitude 112.77°

Galactic Latitude 61.47°

Constellation 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.

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.

Distance (parsec) 24.88 pc

Distance (light year) 81.11 ly

Heliocentric radial velocity -9 km/s

Proper Motion RA 0.118 arcsec/year

Proper Motion Dec -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.

Absolute magnitude 2.03

Spectral Type A5V

Color Index (B-V) 0.16

Temperature of Alcor 8486K

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

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

Alternative designations of Alcor

Proper Name Alcor

Flamsteed designation 80 Ursae Majoris

Henry Draper Catalogue HD116842

SAO Catalogue SAO28751

Hipparcos Catalogue HIP65477

Durchmusterung Catalogue BD+55 1603

Gliese Catalogue NN 3785

General Catalogue of Variable Stars 6238

In Evidence

Other stars in Ursa Major