The Sco–Cen OB association is the main part of a large complex of recent (<20 million years) and ongoing star-formation. The complex contains several star-forming molecular clouds in Sco–Cen's immediate vicinity.
The stellar members of the Sco–Cen association have nearly parallel velocity vectors, moving at about 20 km/s with respect to the Sun. The variation of velocity within the subgroups is about 1–2 km/s, and the group is most likely no longer held together by gravity. Several supernovae have exploded in Sco–Cen over the past 15 million years, leaving a network of expanding gas superbubbles around the group.
Iron-60 found in fossilised bacteria in sea floor sediments suggests there was a supernova near the solar system about 2,000,000 years ago. Iron-60 is also found in sediments from 8 million years ago.
References[change | change source]
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