Sep 16

"The Cepheid Distance Scale: Recent Progress in Fundamental Techniques"
Thomas Barnes, University of Texas at Austin

"I will examine progress on the Pop I, fundamental-mode Cepheid distance scale with emphasis on recent developments in geometric and quasi-geometric techniques for Cepheid distance determination. Specifically, the techniques considered are the surface brightness method, interferometric pulsation method, and trigonometric measurements. The three techniques are found to be in excellent agreement for distance measures in the Galaxy. The velocity p-factor is of crucial importance in the first two of these methods. A comparison of recent determinations of the p-factor for Cepheids demonstrates that observational measures of p and theoretical predictions agree within their uncertainties for Galactic Cepheids."

Sep 23

"Characterizing the Chemistry of the Milky Way Stellar Halo: Detailed Chemical Abundances in a Metal-Poor Stellar Stream"
Ian Roederer University of Texas at Austin

"To what extent does stellar nucleosynthesis trace the hierarchical merger history of the Galaxy, and to what degree is it necessary to know the kinematics of a star in order to correctly interpret its chemical enrichment history? We examine the composition of one of the confirmed building blocks of the halo, a stellar stream. Chemically, the stream does not resemble any present-day Milky Way dwarf galaxies. The stream may share a common origin with the globular cluster M15, which has similar kinematics and whose stars show unusually large variations in bulk neutron-capture enrichment relative to other metal-poor globular clusters."