Astrophysics Seminar: Prof. Lea Hirsch, University of Toronto Mississauga


Location: 184 Nieuwland Science Hall (View on map )

Here Come the suns: planets and binaries orbiting nearby Sun-like stars

Prof. Lea Hirsch
Department of Astronomy & Astrophysics
University of Toronto Mississauga

Nearly half of all Sun-like stars host stellar companions, and planets around G and K stars seem to be incredibly common. Stellar multiplicity might affect planet formation and evolution in many different ways, from perturbation and truncation of the protoplanetary disk to destabilizing or evolving planetary orbits. Yet most surveys for planets either intentionally avoid stellar multiple systems, or have biases associated with unknown stellar companions. I will describe the results of a volume-complete survey for both stellar and giant planetary companions to G and K stars within 25 pc, which shows that wide stellar companions have a minimal effect on the frequency of giant planets, but may have an effect on the architectures of these planetary systems. In contrast, close stellar binaries host giant planets at a significantly lower frequency than single stars. Meanwhile, I will discuss the difficulties associated with searching for planets in binary systems – especially close binaries with double-lined spectra – and some unexpected nearby white dwarf binary systems discovered as part of our survey.

Hosted by Prof. Weiss