Tomothy C. Beers (National Optical Astronomy Observatory, Tucson)

Carbon-Enhanced Metal-Poor (CEMP) Stars: Probes of Nucleosynthesis from the First Generation of Stars in the Universe

CEMP-no stars are a subclass of very ([Fe/H] < -2.0) and extremely ([Fe/H] < -3.0) metal-poor stars in the Milky Way (including the most iron-deficient stars known) with no strong enhancements of s-process elements, which might be attributed to mass-transfer from a binary companion. In addition to carbon, these stars exhibit enhancements of N, O, and other light elements such as Na, Mg, Al, and Si, a pattern that may be uniquely produced by the first generation stars in the early Universe. These stars have also been recently linked to the observed abundance pattern in a high redshift (z = 3.1), very metal-poor ([Fe/H = -2.8) damped Lyman-alpha cloud. I will discuss the discovery of CEMP-no stars, new surveys that are expanding their numbers, evidence against a binary/mass-transfer origin, and planned future spectroscopic exploration of these interesting objects.