S316p.33 — Multiple populations in M3: chemical abundances in AGB stars.

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Aug 10th at 6:00 PM until 7:30 PM




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Author(s): Sanzia Alves2, Rodrigo Contreras Ramos2, Pia Amigo2, Aldo A. R. Valcarce2, Cristian Cortés3, Gergely Hadju2, Johanna Jurcsik1, Manuela Zoccali2, Márcio Catelan2

Institution(s): 1. Konkoly Observatory, 2. Pontificia Universidad Catolica de Chile, 3. Universidad Metropolitana de Ciencias de la Educacion

Since the discovery of multiple populations in globular clusters, it is widely accepted that most globulars have at least two populations that can be classified in terms of their Na abundance, with the Na-poor stars belonging to the first stellar population, and the Na-rich stars to a second population. In the case of NGC 6752, it has been found that all the Na-rich stars fail to reach the asymptotic giant branch (AGB) phase, thus suggesting that the second-generation stars in this cluster all become so-called AGB-manqué stars after a hot horizontal branch (HB) phase. In contrast, stars belonging to both populations are present on the AGB phase in 47 Tucanae, which is consistent with the lack of a sizeable population of very hot HB stars in this cluster. In this contribution, we use high-resolution spectra obtained with UVES@VLT to analyze the chemical behavior of AGB stars in M3 (NGC 5272), a globular cluster with an HB morphology intermediate between those of NGC 6752 and 47 Tuc, to check whether second-generation stars in this cluster undergo an AGB-manqué phase as in NGC 6752, or whether instead they are able to successfully reach the AGB, as seen in 47 Tuc.