2009.11.28
Wikipedia:
Alpha Centauri.
"Alpha Centauri ... is the brightest star in the
southern constellation of Centaurus and an
established binary star system.... To the unaided
eye it appears as a single star, whose total visual
magnitude would identify it as the third brightest
star in the night sky. Alpha Centauri is the
closest star system to the Solar System, being only
1.34 parsecs, or 4.37 light years away from our
Sun."
50 years of space exploration.