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Planetary
Nebulae in Nearby Galaxies:
Planetary nebulae (PNe) trace stellar populations with ages ~1--10 Gyr
and are an ideal probe of the dynamics of low to intermediate mass stars
in nearby galaxies. Their emission lines can provide accurate
line-of-sight velocities with a modest investment of telescope time.
Abundances from PNe and HII regions allow us:
(1) to derive an approximate enrichment history for a galaxy from
intermediate ages to the present day, complementing photometric or
spectroscopic metallicity information derived from old red giants;
(2) to measure abundances at different locations, testing the
homogeneity with which elements are distributed within a galaxy.
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