Small Samples No More: Probing the Evolution of Massive Stars

Abstract

Evolved massive stars --- the post-main sequence descendants of stars with initial masses higher than roughly 8 solar masses --- are rare yet critically important objects. As residents of their host galaxies, they inject radiation and matter into their surroundings on short timescales before exploding as supernovae. Individually, they are fascinating astrophysical laboratories in which many of the unknowns of stellar evolution coalesce. Due to their rarity, these multitudinous unknowns remain under-constrained. In this work, I attempt to understand evolved massive stars using a variety of techniques that have only recently begun to be applied to these interesting objects. My studies of populations of young stars reveal that the massive star binary fraction can be inferred using only simple demographic statistics. However, these methods can only be used given large numbers of well-classified stars, and I show that even using advanced machine learning techniques, existing data are insufficient to classify these stars. Finally, I demonstrate the immense potential of using asteroseismology to probe the interiors of evolved massive stars, and discover a new class of pulsating supergiant.