Joint Astrophysics Colloquium

Special Astrophysics Seminar

Ultra-compact binary stars

Gijs Nelemans

Radboud University Nijmegen

I will give a general introduction to ultra-compact binaries, double stars with orbital periods less than about one hour. These are interesting for a number of reasons, ranging from open questions in binary evolution theory that are relevant for many of the high-energy phenomena in the universe to the expectations for space based gravitational wave detectors. I will focus on recent results on the formation and evolution of these binaries, their Galactic population and the peculiar phenomena associated with the accretion of chemically peculiar material onto white dwarfs and neutron stars in these systems.