Wednesday, June 11 - Plenary Session

Name:  Natalie R. Hinkel

Affiliation:  San Francisco State University

Title:  Variations in the Composition of Cool Stars

Understanding the chemical composition of cool stars in the solar neighborhood is vital to answering key formation and evolutionary questions for not only our local universe, but also for planets orbiting those stars. However, over the last few decades, abundance measurement techniques have changed -- such as line lists, atmospheric models, and adopted solar abundances, introducing systematic and stochastic differences between data sets. These differences make comparisons between data sets, let alone stars, very difficult to quantize. I will discuss abundance data from a homogenized compilation of literature sources for ~3000 stars found within 150pc of the Sun, as part of the Hypatia Catalog. This large collection of chemical abundances allows for a more copacetic understanding of stellar compositions, without bias towards a given group or technique. I will also present abundance results from a collaboration with multiple, international groups who analyzed the same high-resolution spectra using a variety of techniques. Our conclusions from their analysis, as it pertains to the field, suggests that while there are many discrepancies between groups, a standard method of measuring abundances may be in order. With help from the community, the stellar abundance issues may be disentangled to provide an accurate portrayal of the compositions of nearby stars.