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
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
for life, our stellar neighbor is a well respected candidate.