Globular
star clusters contain some of the oldest surviving stars in the universe, as
seen by the NASA/ESA Hubble Space Telescope.
Astronomers
have identified over 11,000 globular clusters in the Virgo cluster of galaxies,
most of which are more than 5 billion years old. The giant elliptical galaxy Messier
87 resides within three million light-years of Virgo's center and has more than its
share of globular clusters — possibly cannibalized from smaller galaxies that
ventured too close.
Researchers
recently found evidence for this in the composition of Messier 87's globular
clusters, which tend to lack heavy elements such as iron. That indicates the
galaxy stole those clusters from smaller dwarf galaxies that contain similar
clusters. Better understanding of globular clusters should provide more insight
into the early, star-forming episodes that mark galaxy formation.
— NASA/ESA and SPACE.com Staff
Credit: NASA, ESA and
Eric Peng (Peking University, China)
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