Another one grinds the dust: Variability of the planetary debris disc at the white dwarf SDSS J104341.53+085558.2

TL;DR

This study presents nine years of spectroscopic observations of the white dwarf SDSS J104341.53+085558.2, revealing variability in its gaseous debris disc and analyzing its composition and accretion rates, contributing to understanding planetary debris around white dwarfs.

Contribution

It provides long-term spectroscopic data showing morphological variations in the debris disc and detailed elemental abundance analysis, highlighting the disc's variability and composition.

Findings

Observed morphological variations in the Ca II triplet emission over nine years.

Derived elemental abundances consistent with planetary crust material.

Estimated accretion rates comparable to other debris disc systems.

Abstract

We report nine years of optical spectroscopy of the metal-polluted white dwarf SDSS J104341.53+085558.2, which presents morphological variations of the line profiles of the 8600 \AA\ Ca II triplet emission from the gaseous component of its debris disc. Similar changes in the shape of the Ca II triplet have also been observed in two other systems that host a gaseous disc, and are likely related to the same mechanism. We report the Mg, Si, and Ca abundances of the debris detected in the photosphere of SDSS J1043+0855, place upper limits on O and Fe, and derive an accretion rate of (2.5 - 12)x$10^8$ g/s, consistent with those found in other systems with detected debris discs. The Mg/Si ratio and the upper limit on the Fe/Si ratio of the accreted material broadly agree with those found for the crust of the Earth. We also review the range of variability observed among white dwarfs with planetary debris discs.