Abstract

RR Lyrae variable stars are fundamental contributors to the cosmic distance ladder.  They generally have very regular observational properties that aid their utility as distance indicators, but those relationships have needed refreshment for a long time.  Here we report recent results in the effort to re-define their "Bailey Diagram", their Delta-S relationship, and their alpha-element-to-metallicity abundance trend.  Then we report some preliminary results from a study of the surprisingly common appearance of He I and He II emission in RR Lyrae spectra near light maxima of their pulsational periods.