Abstract
AM CVn systems are a small group of mass-transferring ultracompact binaries consisting of a white dwarf primary and a degenerated or semi-degenerated secondary. They are the endpoints of binary stellar evolution, having survived two common-envelope phases and showing orbital periods between 5.4-65 min (Solheim 2010). They are the only known sources of gravitational waves in the LISA regime and will act as LISA verification sources.
