Abundances of dwarf stars in the Galactic Bulge:
Abundances of a few giant stars in the Galactic Bulge indicate a dispersion in metallicity, with a mean somewhat below Solar. Yet, the Sun, at ~8.4 kpc from the Bulge is metal-rich by 50% relative to the local neighborhood. Did the Sun migrate outward from the Galactic center? How do abundances for G- dwarfs in the Bulge compare to the Sun? What is the age-metallicity relation in the Bulge? Abundances in giant stars, while easier to observe than dwarfs, suffer from interpretation problems arising with dredge-up, proton-capture nucleosynthesis, and other factors that are absent in dwarfs. Ideally, one would like to map the abundances and the dispersions of many elements in dwarfs from the Galactic Center out to the Solar neighborhood to determine just how unusual the Sun is, where it may have formed, and simultaneously measure the abundance patterns of the Galaxy as a function of galactocentric distance and age.
Requires spectra of ~10,000 stars to 20th mag (fainter along lines of heavy extinction) at moderate resolution, in order to determine abundances at ~30 positions (10 radii and 3 heights above the plane).