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OATS-DAUT SEMINAR
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Speaker: Santi Cassisi (INAF/Oss. Astr. Teramo)

Title: The Helium abundance in Galactic Globular Clusters:
some new -unexpected- results

Date: Wednesday, October 11th, 2006
Time: 12:00 noon
Venue: Villa Bazzoni

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Abstract:
We briefly review the methods for measuring the initial He abundance in stars belonging to galactic globular clusters based on stellar observables such as the "R" parameter and "A" one. We discuss the uncertainties affecting the theoretical calibrations of these methods and, show the comparison with empirical evidence. Some new - and unexpected - results obtained for omega Centauri, NGC2808 and the two twin clusters NGC6388 and NGC6441 are discussed.
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