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 gravitationally unbound. Several supernovae have exploded in Sco–Cen over the past 15 million years, leaving a network of expanding gas superbubbles around the group.
To explain the presence of radioactive 60Fe in Earth's deep ocean ferromanganese crust, it has been suggested that a nearby supernova, perhaps a member of Sco–Cen, exploded in the Sun's vicinity about 3 million years ago.
References[change | change source]
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- Mark J. Pecaut, Eric E. Mamajek & Eric J. Bubar 2012. A revised age for Upper Scorpius and the star formation history among the F-type Members of the Scorpius-Centaurus OB Association. Astrophysical Journal 746 (2): 154. http://adsabs.harvard.edu/abs/2012ApJ...746..154P. .
- Preibisch, T. & Mamajek E. 2009. "The nearest OB Association: Scorpius-Centaurus (Sco OB2)". Handbook of Star-Forming Regions 2: 0.
- Madsen S. et al 2002. "Astrometric radial velocities. III. Hipparcos measurements of nearby star clusters and associations". Astronomy & Astrophysics 381 (2): 446–463. .
- = no longer held together by gravity
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- Fields B.D; Hochmuth K.A. & Ellis J. (2005). "Deep-Ocean crusts as telescopes: using live radioisotopes to probe supernova nucleosynthesis". Astrophys. J. 621 (2): 902–907. .