Alnair - α Gruis (alpha Gruis)

Alnair, also designated as α Gruis (alpha Gruis), is a variable and double sub-giant star in the constellation of Grus.

Alnair visual magnitude is 1.74, making it the 30th brightest star in the sky. Thanks to its high brightness, Alnair is clearly visible when observed from locations with dark skies, and should be also quite easily visible from light polluted areas.

The proper motion of Alnair is 0.129 arcsec per year in Right Ascension and -0.151 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Key facts about Alnair

Celestial coordinates and finder chart of Alnair

Alnair 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 Alnair are provided in the following table:

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

Visibility of Alnair from your location

Alnair - α Gruis (alpha Gruis) is currently not visible from Greenwich, United Kingdom edit_location_alt

Distance of Alnair from the Sun and relative movement

Alnair is distant 101.37 light years from the Sun and it is moving far from the Sun at the speed of 12 kilometers per second.

Spectral properties of Alnair

Alnair belongs to spectral class B7 and has a luminosity class of IV corresponding to a sub-giant star.

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

Alnair star system properties

Alnair is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the Alnair double sysyem:

Alternative designations of Alnair