Program: GN-2015A-Q-76

Metal-poor stars are local relics of high redshift star formation. The chemical abundances of large samples of metal-poor stars can be used to investigate Population III stellar populations, supernovae, and nucleosynthesis as well as the galactic chemical evolution of the Milky Way and its progenitor halos. However, current progress on the study of metal-poor stars is limited by their faint apparent magnitudes. The acquisition of high signal-to-noise spectra for faint metal-poor stars requires a major telescope time commitment, making the construction of large samples of metal-poor star abundances prohibitively expensive. The HK and HES Surveys have been exhausted of their bright metal-poor star candidates, while saturation in SDSS imaging precludes its use for the identification of bright metal-poor stars. Schlaufman & Casey (2014) used the lack of molecular absorption at 4.6 microns to efficiently identify bright metal-poor giants, and we propose to observe all 344 of their candidate metal-poor stars with V < 12 observable in 2015A. We expect to identify more than 120 stars with [Fe/H] < -2.0. The bright metal-poor stars identified from this survey and confirmed by ground-based high-resolution spectroscopy are bright enough to be observed by HST in the ultraviolet to measure Ge, As, Se, Cd, Lu, Os, Pt, and Hg and break the degeneracies between different models for the chemical enrichment of metal-poor stars. To complete our all-sky survey, we will apply for a similar allocation in 2015B to observe another ~300 metal-poor candidates. Once completed, this program should yield more than 250 bright stars with [Fe/H] < -2.