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Achernar - α Eridani (alpha Eridani)

Achernar, also designated as α Eridani (alpha Eridani), is a variable main-sequence star in the constellation of Eridanus.

Achernar visual magnitude is 0.46, making it the 9th brightest star in the sky. Thanks to its high brightness, Achernar 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 Achernar:

Color of Achernar ⬤

Magnitude of Achernar 0.46

Class Main-sequence

VISIBILITY RIGHT NOW Achernar - α Eridani (alpha Eridani) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Celestial coordinates and finder chart of Achernar

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

Right Ascension J2000 01h 37m 42s

Declination J2000 -57° 14’ 12”

Galactic Longitude 290.84°

Galactic Latitude -58.79°

Constellation Eridanus

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

Finder chart Achernar - α Eridani (alpha Eridani) star

Simplified finder chart for Achernar - α Eridani (alpha Eridani).

Visibility of Achernar from your location

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

Achernar - α Eridani (alpha Eridani) is currently not visible from Greenwich, United Kingdom edit_location_alt

Digitized Sky Survey image of Achernar

The image below is a photograph of Achernar 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 Achernar is 0.095 arcsec per year in Right Ascension and -0.035 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of Achernar - α Eridani (alpha Eridani) star

DSS2 image of Achernar. The red arrow shows the motion of Achernar during the next 1000 years (1.58 arcmin in Right Ascension and -0.58 arcmin in declination);

Distance of Achernar from the Sun and relative movement

Achernar is distant 143.74 light years from the Sun and it is moving far from the Sun at the speed of 16 kilometers per second.

Distance (parsec) 44.09 pc

Distance (light year) 143.74 ly

Heliocentric radial velocity 16 km/s

Proper Motion RA 0.095 arcsec/year

Proper Motion Dec -0.035 arcsec/year

Spectral properties of Achernar

Achernar belongs to spectral class B3 and has a luminosity class of V corresponding to a main-sequence star.

Absolute magnitude -2.76

Spectral Type B3V

Color Index (B-V) -0.16

Temperature of Achernar 12692K

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

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

Alternative designations of Achernar

Proper Name Achernar

Bayer designation α Eridani
(alpha Eridani)

Henry Draper Catalogue HD10144

SAO Catalogue SAO232481

Hipparcos Catalogue HIP7588

Durchmusterung Catalogue CP-57 334

FK5 Catalogue 54

General Catalogue of Variable Stars Var

In Evidence

Other stars in Eridanus