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Multiple population theory: The extreme helium population problem

Published online by Cambridge University Press:  01 October 2008

Sukyoung K. Yi*
Affiliation:
Yonsei University, Department of Astronomy, Seoul 120-749, Korea email: [email protected]
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Abstract

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The spreads in chemical abundances inferred by recent precision observations suggest that some or possibly all globular clusters can no longer be considered as simple stellar populations. The most striking case is ω Cen in the sense that its bluest main-sequence, despite its high metallicity, demands an extreme helium abundance of Y ≈ 0.4. I focus on this issue of “the extreme helium population problem” in this review.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2009

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