Program: GN-2016A-Q-75

Title:An All-Sky Search for the Brightest Metal-poor Stars (North)
PI:Kevin Schlaufman
Co-I(s): Andrew Casey, Vinicius Placco, Timothy Beers

Abstract

Metal-poor stars are local relics of the high-redshift Universe. The acquisition of high signal-to-noise spectra for faint metal-poor stars requires a major telescope time commitment though, 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 stars, and we propose to observe all 310 of their candidate metal-poor stars with V < 12.5 observable in 2016A. We expect to identify more than 110 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. Those abundances have the potential to break the degeneracies between different models for the chemical enrichment of metal-poor stars. The proposed observations will continue our all-sky survey that was started in 2015A, and the overall program should eventually yield more than 500 bright stars with [Fe/H] < -2.

Publications using this program's data