When do stars in 47 Tucanae lose their mass?

Abstract

By examining the diffusion of young white dwarfs through the core of the globular cluster 47 Tucanae, we estimate the time when the progenitor star lost the bulk of its mass to become a white dwarf. According to stellar evolution models of the white-dwarf progenitors in 47 Tucanae, we find this epoch to coincide approximately with the star ascending the asymptotic giant branch ($3.0\pm 8.1$ Myr before the tip of the AGB) and more than ninety million years after the helium flash (with ninety-percent confidence). From the diffusion of the young white dwarfs we can exclude the hypothesis that the bulk of the mass loss occurs on the red-giant branch at the four-sigma level. Furthermore, we find that the radial distribution of horizontal branch stars is consistent with that of the red-giant stars and upper-main-sequence stars and inconsistent with the loss of more than 0.2 solar masses on the red-giant branch at the six-sigma level.

8 pages, 4 figures, version accepted by the Astrophysical Journal

References in corpus (15)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Improving PARSEC models for very low mass stars
• The ACS Nearby Galaxy Survey Treasury
• Scaled solar tracks and isochrones in a large region of the Z-Y plane I. From the ZAMS to the TP-AGB end for 0.15 - 2.5 Mo stars
• The ACS Nearby Galaxy Survey Treasury IX. Constraining asymptotic giant branch evolution with old metal-poor galaxies
• HST Proper Motions and Stellar Dynamics in the Core of the Globular Cluster 47 Tucanae
• The fraction of second generation stars in Globular Clusters from the analysis of the Horizontal Branch
• Mass loss on the red giant branch: the value and metallicity dependence of Reimers' η in globular clusters
• The First Empirical Mass Loss Law for Population II Giants
• Evolution of Thermally Pulsing Asymptotic Giant Branch Stars IV. Constraining Mass-Loss & Lifetimes of Low Mass, Low Metallicity AGB Stars
• Stellar Exotica in 47 Tucanae
• Mass Outflow from Red Giant Stars in M13, M15, and M92
• An empirical mass-loss law for Population II giants from the Spitzer-IRAC survey of Galactic globular clusters
• A population of binaries in the Asymptotic Giant Branch of 47 Tucanae?
• A Measurement of Diffusion in 47 Tucanae

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• Deep HST Imaging in 47 Tucanae: A Global Dynamical Model
• Formation and Evolution of Blue Stragglers in 47 Tucanae
• Dynamical estimate of post main sequence stellar masses in 47 Tucanae
• The Onset of Convective Coupling and Freezing in the White Dwarfs of 47 Tucanae
• The Cooling of Old White Dwarfs in 47 Tucanae
• Observations of the Bright Star in the Globular Cluster 47 Tucanae (NGC 104)