Program: GS-2005B-C-7

Title:Nucleosynthesis in the final stages of stellar evolution
PI:Thomas Lebzelter
Co-I(s): Ken Hinkle, Peter Wood, Verne Smith

Abstract

One of the important characteristics of AGB evolution is the 3rd dredge-up where freshly produced $^{12}$C and s-process elements are brought up into the stellar atmosphere. Heavy mass loss occurring during and following the AGB phase enriches the interstellar material with the elements produced in stellar interiors. Stellar evolution models now provide quite detailed predictions for the 3rd dredge-up enrichment but quantitative checks so far are restricted to field stars or to indirect methods. Using improved model atmospheres and high resolution Phoenix/Gemini spectra we propose the determination of carbon and oxygen abundances and isotopic ratios for stars along the AGB of the LMC globular cluster NGC 1846. The young globular clusters of the LMC provide an ideal laboratory for studying AGB evolution that is not available in the Milky Way. The sensitivity provided by Phoenix on an 8 m class telescope allows high spectral resolution observations of both giants and AGB stars in NGC 1846.

Publications using this program's data