Heidelberg Joint Astronomical Colloquium

Speaker Chris Sneden
Title New Initiatives on RR Lyrae Chemical Compositions

RR Lyrae stars provide crucial information on topics ranging from stellar interior/envelope physics, to absolute magnitude calibrations, to the fundamental distance scale. Yet their chemical compositions have not been investigated as extensively as have other types of low metallicity stars. In this talk I will discuss my (reluctant!) entry into RR Lyr abundance studies via a unique neutron-capture-rich member of this class, then summarize the spectroscopic survey of 10 RR Lyr stars observed intensively at all pulsational phases by George Preston and analyzed by Bi-Qing For. Finally I will describe the ongoing metallicity/velocity survey of hundreds of RR Lyr stars by the Carnegie/Texas collaboration, whose ultimate goal is to apply single-phase spectra of candidate stars to Galactic structure and population studies.