Constraining white dwarf viscosity through tidal heating in detached binary systems

Understand

Although the internal structure of white dwarfs is considered to be generally well understood, the source and entity of viscosity is still very uncertain.

• We propose here to study white dwarf viscous properties using short period (< 1 hr), detached white dwarf binaries, such as the newly discovered ~12.8 min system.
• These binaries are wide enough that mass transfer has not yet started but close enough that the least massive component is subject to a measurable tidal deformation.
• The associated tidal torque transfers orbital energy, which is partially converted into heat by the action of viscosity within the deformed star.