The nearest OB association to the Sun, also known as the Sco OB2 association or simply the Sco–Cen association. It stretches for about 600 l.y. along Gould’s Belt from Scorpius to Centaurus and Crux. There are three subgroups: Upper Scorpius, Upper Centaurus Lupus, and Lower Centaurus Crux, with estimated ages 5 million years, 17 million years, and 16 million years respectively, and distances 473 l.y., 456 l.y., and 385 l.y. Current estimates place membership of the Scorpius–Centaurus association at over 500 stars, mostly of spectral types B and A. Antares is its brightest member.