The Effects of Attenuated Magnetic Braking in Cataclysmic Variables

Joshua Aiken (Bishop's University )

Cataclysmic variables (CVs) are close interacting binary stars with a white dwarf (WD) accretor and a typically unevolved donor star. The two dominant orbital angular momentum loss (AML) mechanisms present in CV evolutions are magnetic braking (MB) and gravitational wave radiation (GR). For MB, angular momentum is directly removed from the rotation of the donor star until it becomes fully convective, after which GR becomes the sole AML mechanism. In previous attempts to model the evolution of CVs, MB turns off completely and only GR drives the evolution of the system. In this talk, I present an alternative model which allows an attenuated amount of MB to dissipate angular momentum after the donor star’s core becomes fully convective. Using the MESA stellar evolution code, I also explore the model’s effects on the late evolutionary stages of CVs and show that this model can easily solve the ‘minimum orbital period’ problem.