[ken-tawr-uh
s] 
| Astronomy. a triple-star system that is the brightest celestial object in the constellation Centaurus. |
| Alpha Centauri (āl'fə sěn-tôr'ē) Pronunciation Key
A triple star system in the constellation Centaurus that is the third brightest star in the night sky, with an apparent magnitude of -0.27, and the star nearest to Earth, at a distance of about 4.2 light-years. The two brighter stars, Alpha Centauri A and B, form a binary star system, which is orbited by Proxima Centauri, a smaller, dimmer star. |