The
Scorpius–Centaurus Association (sometimes called
Sco–Cen or
Sco OB2) is the nearest
OB association to the
Sun. This
stellar association is composed of three subgroups (Upper Scorpius, Upper Centaurus–Lupus, and Lower Centaurus–Crux), whose mean distances range from 380 to 470
light years. Using improved
Hipparcos data, Rizzuto and colleagues analysed nearby stars more closely, bringing the number of known members to 436. They doubt the need to add a subclassification because they found a more continuous spread of stars.