With the aid of a Leverhulme Research Grant, Dr Pier-Emmanuel Tremblay and Dr Tim Cunningham from the Department of Physics will use three-dimensional numerical simulations of the white dwarf surface to dissect frequent planetesimal accretion events (where the white dwarf accretes planetary remains) to an unprecedented level of accuracy.

As many as 95% of these stellar remnants have a convective surface made of pristine hydrogen and helium gas, in which metallic debris plunge and become mixed by bulk fluid motions in a matter of hours.

To date, almost all studies have relied upon a 60-year-old, 1D prescription of convection, although it has been shown to have a major shortcoming in that it produces an on/off discontinuity at the top and base of the unstable convective layers. The method completely neglects convective overshoot - the phenomenon where 3D plumes travel outside the unstable regions.