Modelling the distributions of white dwarf atmospheric pollution: a low Mg abundance for accreted planetesimals?

Understand

The accretion of planetesimals onto white dwarf atmospheres allows determination of the composition of this polluting material.

• This composition is usually inferred from observed pollution levels by assuming it originated from a single body.
• This paper instead uses a stochastic model wherein polluting planetesimals are chosen randomly from a mass distribution, finding that the single body assumption is invalid in >20% of cases.
• Planetesimal compositions are modelled assuming parent bodies that differentiated into core, mantle and crust components.