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. We find this to be not earlier
than 40 Myr before the star reaches the tip of the asymptotic giant branch.
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 and well after the helium flash. With the current
data and analysis we cannot exclude some mass loss on the red-giant branch, but
we argue that the bulk of the mass loss must occur very late in the star's
history on the asymptotic-giant branch. We also confront the observed
magnitudes of stars on the horizontal branch in 47 Tucanae and find that they
are consistent with the latest theoretical models of the horizontal branch
stars of \$0.8-0.9 M\_ødot\$, further supporting the conclusion that the stars in
47 Tucanae and likewise in other clusters lose the bulk of their mass on the
asymptotic-giant branch.
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