Karen Kwitter (Williams College, USA)
We review gas-phase abundances in PNe, and describe their dual utility as archives
of original progenitor metallicity via the alpha elements, as well as sources of processed
material from nucleosynthesis during the star’s evolution, i.e., C, N, and s-process
elements. Observational methods, including analysis tools and computer modeling,
are discussed, along with the status of recombination-line vs. forbidden-line
abundance determinations. We also summarize results from a recent collaborative
comparison with several abundances research groups. Finally, we suggest areas
where more work is needed to improve our abilities to determine abundances in PNe.
Review presented at the IAU Symposium 283, Planetary Nebulae: an Eye to the Future, 25-29 July 2011, Tenerife, Spain.