This NASA/ESA Hubble Space Telescope has given us this stunning view of the bright Alpha Centauri A
(on the left) and Alpha Centauri B (on the right), shining like huge cosmic headlamps in the dark.
But Alpha Centauri A
is also very important to astronomers: almost a twin to the Sun in mass, temperature, chemical composition and age, it provides an ideal natural laboratory to compare other characteristics of the two stars.
There could well be an Earth-size planet in that Goldilocks sweet spot, not too cold and not too hot, making Alpha Centauri a
compelling target to search for intelligent life.
But because Alpha Centauri A
is bigger, brighter and more rambunctious, any small planets orbiting it would be harder to find.
It is actually a triple star-a system consisting of two stars similar to the Sun orbiting close to each other, designated Alpha Centauri A
and B, and a more distant and faint red component known as Proxima Centauri.
Unlike the Sun and Alpha Centauri A
, its surface doesn't vibrate--making it ideal for an extremely sensitive radial-velocity planet hunt.
Are the three stars that constitute the Alpha Centauri star system - Alpha Centauri A
, B, and Proxima Centauri - part of one gravitationally-bound triple system?
It is part of a triple system consisting of a pair of Sun-like stars, Alpha Centauri A
and B, and a more distant and faint red companion, Proxima Centauri.
Another group, Larry DeWarf, Edward Guinan, and Jenny Carton (Villanova University), found that the coronal X-ray emission from the most massive star in the Alpha Centauri triple system, Alpha Centauri A
, has decreased eightyfold in just the past five years.
If such planets exist in the Alpha Centauri A
and B system .
It consists of two stars similar to the Sun that form a relatively tight binary, Alpha Centauri A
and B, and a red dwarf known as Proxima Centauri that lies roughly 15,000 astronomical units from the main pair.