09/25/2026
Where is the Sun
as seen from Alpha Centauri?
We see Alpha Centauri in the sky near the Southern Cross.
• As viewed from the Alpha Centauri system, our sun is projected against the star fields of the Milky Way. It forms another "leg" in the zig-zag ("W") of Cassiopeiae, and shines as a +0.5 magnitude star – a similar brightness as Procyon in our sky.
• Eta Cassiopeiae, being 19.3 light-years from Earth, appears 0.5 magnitude dimmer because it lies 4.2 light-years farther from Alpha Centauri. It is at mag. 3.9 in the Alpha Centauran sky.
• Because the other stars in the Cassiopeia/Perseus region lie so far, they don't shift appreciably or have a noticeable change in magnitude.
• Our sun is about 5º from the Double Cluster.
The Alpha Centauri system – third brightest in our sky – consists of three stars, two closely separated luminaries similar to the sun, and a third component about 0.2 light-years from the other two. It is a faint red dwarf and merits the name Proxima as it is the closest star to our sun. Proxima, shines in the Alpha Centauran sky at magnitude 4.4, being a moderately dim star.
• Interestingly, the sun is not the closest star to the Alpha Centauri system. That honor falls upon Luhman 16, a pair of brown dwarfs, some 3 light-years toward the constellation Vela. (At 6.5 light-years distant, Luhman 16 ranks third in the nearest stars to the sun.)
As you gaze towards the Double Cluster,
imagine what the view looks like in the Alpha Centauran sky!
