- Annalisa Pillepich (MPIA-HD)
Shazrene Mohamed (SAAO) - "Clues to stellar evolution from the dusty envelopes of interacting binaries"
The physics of binary interactions is a major source of uncertainty for many problems in astrophysics, from the contributions of stars to the integrated light, dust and gas budgets of galaxies to the elusive progenitors of Type Ia supernovae. In this talk I will review the use of a new generation of 3D models and high resolution observations of dusty interacting binaries (e.g. symbiotic binaries) to test and constrain binary evolution theory. The extended envelopes around these systems are a fossil record of their mass-loss history; their structure (with shells, arcs, spirals, jets, torii and disks) not only give clues to the physical processes driving stellar outflows, but also their impact on, and the role played by, a nearby companion star. Studies of Mira AB in particular (many carried out at the CfA) have led to the proposal of a new binary interaction mode, Wind Roche-Lobe OverFlow (WRLOF), in which mass transfer occurs when a slow, dense stellar wind rather than the star itself fills the Roche lobe and is funneled into the potential well of the companion. I will discuss the implications of this new mode for a wide range of related systems (e.g. chemically peculiar stars, X-ray binaries and supernova progenitors) and briefly highlight the broader significance for our understanding of the dust and chemical evolution of galaxies.