Every star is pretty huge, compared to anything in our life experience. In size. Betelgeuse: Red giant. Diameter 1,180 solar radii. Aldebaran: Orange giant: 45 solar radii. Alpha Centauri - Which...
"An alpha centauri" is wrong, it is a proper name, so there are not several "alpha centauris".
The most notable feature of Alpha Centauri is that it is the star system nearest to us, after our own...