Alpha Centurion

Where is or what is Alpha Centurion ?

Um, you mean Alpha Centauri?

Here you go:

http://en.wikipedia.org/wiki/Alpha_Centauri

What is the diffrence ?

I think its a star constallation, but I may be wrong!

I was close. Its the biggest star in the southern constallation!

Not quite. "Alpha" is the label traditionally given to the brightest star (from Earth) in a constellation such as "the Centaur". The next brightest were labelled beta, gamma and so on. See Bayer Designation

Alpha Centauri is the brightest star in the constellation Centaurus (the Greek letter Alpha is given to the brightest star, usually unnamed ones, in a constellation).  But some navigators from as early as the 17th century also called it Rigel Kent.  It is the closest extrasolar star to Earth visible with the naked eye; one of Alpha Centauri's companion stars, Proxima Centauri, is actually the closest.

A Centurion was an officer in the Roman army, and the root "centuries" that this word is based off of (because they were traditionally in command of 100 men, but in practice, usually around 80) means 100.  Contrast this to "centaur", which is a mythological creature that is half-man, half-horse, and the basis for the shape of the constellation.

It is 4.5 light years away from earth and is a binary star system comprising of Alpha Centauri and Proxima Centauri.  Like Niven42 said, it is the closest star(s) to earth.

Blaufisch wrote:

It is 4.5 light years away from earth and is a binary star system comprising of Alpha Centauri and Proxima Centauri.  Like Niven42 said, it is the closest star(s) to earth.

Alpha, Beta, and Proxima.  It's a triple system.

   You better fact check that "closest star to Earth" thing. I remember hearing recently they discovered a dim brown dwarf just over 2 light years away. I heard about it 3 to 4 months ago so your source material may not reflect this recent find.

   (Also, the sun is a star so maybe you meant the closest star to our sun.)

Well i thought sirius was nearest...

@taodell:  Not at the moment, but it could in the not-to-distant future:

http://en.wikipedia.org/wiki/Gliese_710