A New Look at Carbon Abundances in Planetary Nebulae
Session 47 -- Planetary Nebulae
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [47.07] A New Look at Carbon Abundances in Planetary Nebulae

K. B. Kwitter (Williams College), R. B. C. Henry (U. of Oklahoma), J. F. Buell (U. of Oklahoma)

We present initial results of a program to study carbon abundances in a sample of planetary nebulae spanning a wide range in progenitor mass, with the goal of determining carbon production in intermediate mass stars. By employing the IUE Final Archive database of spectra which have been reduced in a standardized fashion, we are remeasuring lines of C III] $\lambda$1909 and C IV $\lambda$1549, combining these measurements with optical lines in the literature, and performing a detailed abundance analysis on each sample PN. Through the use of an empirical 5-level atom routine and a photoionization code, we are deducing abundances of He, C, N, O, Ne, and S, as well as nebular density and stellar temperature information for each of our sample objects. Once our sample is complete, we will proceed to infer the chemical yield of carbon using a detailed stellar evolution code. This research is supported by NASA grant NAG 5-2389.