Papers › Asynchronous accretion can mimic diverse white dwarf pollutants I: core and mantle fragments
Asynchronous accretion can mimic diverse white dwarf pollutants I: core and mantle fragments
Marc G. Brouwers, Amy Bonsor, Uri Malamud
The archive published only this paper's code-link row. Authors, date and abstract are from arXiv's metadata (CC0), read from the Kaggle arXiv metadata snapshot of 2026-09-12 where its title matched the archive's; the title is the archive's.
Polluted white dwarfs serve as astrophysical mass spectrometers - their photospheric abundances are used to infer the composition of planetary objects that accrete onto them. We show that due to asymmetries in the accretion process, the composition of the material falling onto a star may vary with time during the accretion of a single planetary body. Consequently, the instantaneous photospheric abundances of white dwarfs do not necessarily reflect the bulk composition of their pollutants, especially when their diffusion timescales are short. In particular, we predict that when an asteroid with an iron core tidally disrupts around a white dwarf, a larger share of its mantle is ejected, and that the core/mantle fraction of the accreting material varies with time during the event. Crucially, this implies that the core fraction of differentiated pollutants cannot be determined for white dwarfs with short diffusion timescales, which sample only brief episodes of longer accretion processes. The observed population of polluted white dwarfs backs up the proposed theory. More white dwarfs have accreted material with high Fe/Ca than low Fe/Ca relative to stellar abundance ratios, indicating the ejection of mantle material. Additionally, we find tentative evidence that the accretion rate of iron decreases more rapidly than that of magnesium or calcium, hinting at variability of the accreted composition. Further corroboration of the proposed theory will come from the up-coming analysis of large samples of young white dwarfs.
Code
Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.
Code Syntology ran Syntology
Not run by Syntology. Nothing on this page verifies that the listed code works.
Results from the paper archive 2025-07-28
No leaderboard rows for this paper in the archive.
Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections