# Polluting White Dwarfs with Perturbed Exo-Comets

## TL;DR

This paper proposes a model explaining how mass-loss during stellar evolution can scatter comets from distant planetary remnants into white dwarf atmospheres, forming debris disks and causing metal pollution.

## Contribution

It introduces a new dynamical model linking stellar mass-loss to comet scattering and debris disk formation around white dwarfs.

## Key findings

- Up to 2% of planetesimals are scattered inward after stellar mass-loss.
- The model explains observed debris disks and metal pollution in white dwarf spectra.
- Planetary remnants can significantly influence white dwarf atmospheric composition.

## Abstract

We present a model to account for the observed debris disks around young white dwarfs and the presence of metal-lines in their spectra. Stellar evolution models predict that the mass-loss on the AGB will be pulsed; furthermore, observations indicate that the bulk of the mass-loss occurs on the AGB. In this case, if the progenitors of the white dwarfs had remnants of planetary formation like the Sun's Oort cloud or the Kuiper Belt and a planet lying within that cloud or nearby, we find that up to 2% of the planetesimals will fall either into planet-crossing orbits or into chaotic regions after the mass-loss, depending on the location and mass of the planet (from Mars to Neptune). This yields a sufficient mass of comets that can be scattered toward the star, form a debris disk and pollute the atmosphere.