Distance from Earth:

4.2 light years

Star name, type:

Alpha Centauri A, sunlike yellow-orange dwarf - G2V

Star mass, radii:

1.09 / 1.28 x Sol

Star2 name, type:

Alpha Centauri B, reddish-orange dwarf - K0V

Star2 mass, radii:

0.90 / 0.80 x Sol

Binary separation:

Yes / 2 / 11.2 - 35.6 AU


Our nearest stellar neighbors

Hypothetical planet location:

1.5 AU

Possible life:



Image description: Two suns in the sky. Alpha Centaurian should have (once in a 75 year lifetime) a chance to see two suns very close next to each other (reminds me on one movie produced by George Lucas). It takes about 80 years for these two stars to complete one orbit around each other. As seen in table above, their closest approach is 11.2 AU.


According to calculations from Paul A. Wiegert and Matt J. Holman (American Astronomical Society - The Astronomical Journal, Volume 113, Number 4 "The stability of planets in the Alpha Centauri system") there should be enough safe place (up to 3.5 AU) for a planet whose orbit will not be disrupted by the gravitational pull of the second star. Our hypothetical planet is located at 1.5 AU because Alpha Centauri A is about 50 % brighter than our Sol.


Also, we should be aware that during 40 year period, there is another relatively close sun heating the planet. As a matter of fact, this even enlarges system's habitable zone. If we are looking for life, our stellar neighbor is a well respected candidate.