Related papers: Polluting White Dwarfs with Perturbed Exo-Comets
Several tens of white dwarfs are known to host circumstellar discs of dusty debris, thought to arise from the tidal disruption of rocky bodies originating in the star's remnant planetary system. This paper investigates the evolution of such…
It is currently admitted that an AGB star in a binary system is likely to pollute its companion with carbon- and s-process-rich matter. After the AGB star has faded into an unconspicuous white dwarf, the polluted companion enters the zoo of…
When a star exhausts its nuclear fuel, it either explodes as a supernova or more quiescently becomes a white dwarf, an object about half the mass of our Sun with a radius of about that of the Earth. About one fifth of white dwarfs exhibit…
Of the 21 known gaseous debris discs around white dwarfs, a large fraction of them display observational features that are well described by an eccentric distribution of gas. In the absence of embedded objects or additional forces, these…
White dwarfs which exhibit transit signatures of planetary debris and accreted planetary material provide exceptional opportunities to probe the material composition and dynamical structure of planetary systems. Although previous…
One challenge with explaining how high levels of planetary debris can enrich, or "pollute", old ($\sim$3 Gyr) and very old ($\sim$10 Gyr) white dwarfs is that debris reservoirs deplete on shorter timescales, akin to the solar system's…
The wind of an asymptotic-giant-branch stars is sufficiently strong that if it is slightly asymmetric, it can propel the star outside of the open cluster of its birth or significantly alter its trajectory through a globular cluster;…
I review some possible processes by which planets and brown dwarfs can influence the evolution of their parent evolved stars. As sun-like stars evolve on the red giant branch (RGB) and then on the asymptotic giant branch (AGB), they will…
Post-asymptotic giant branch (post-AGB) binaries are surrounded by massive disks of gas and dust that are similar to protoplanetary disks around young stars. We assembled a catalog of all known Galactic post-AGB binaries with disks. We…
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…
A significant fraction of isolated white dwarfs host magnetic fields in excess of a MegaGauss. Observations suggest that these fields originate in interacting binary systems where the companion is destroyed thus leaving a singular,…
Over a quarter of white dwarfs have photospheric metal pollution, which is evidence for recent accretion of exoplanetary material. While a wide range of mechanisms have been proposed to account for this pollution, there are currently few…
The persistence of planetary systems after their host stars evolve into their post-main sequence phase is poorly constrained by observations. Many young white dwarf systems exhibit infrared excess emission and/or spectral absorption lines…
White dwarfs with metal-polluted atmospheres have been studied widely in the context of the accretion of rocky debris from evolved planetary systems. One open question is the geometry of accretion and how material arrives and mixes in the…
Beyond the main sequence solar type stars undergo extensive mass loss, providing an environment where planet and brown dwarf companions interact with the surrounding material. To examine the interaction of substellar mass objects embedded…
White dwarfs with metal pollution are caused by the accretion of rocky dust from tidally disrupted minor bodies and are signposts for planetary systems. These minor bodies are perturbed by planets that have survived post-main sequence…
The population of debris discs on the main sequence is well constrained, however very little is known about debris discs around evolved stars. In this work we provide a theoretical framework that considers the effects of stellar evolution…
Although 25%-50% of white dwarfs (WDs) display evidence for remnant planetary systems, their orbital architectures and overall sizes remain unknown. Vibrant close-in (~1 Solar radius) circumstellar activity is detected at WDs spanning many…
Debris disks are the dust disks found around ~20% of nearby main sequence stars in far-IR surveys. They can be considered as descendants of protoplanetary disks or components of planetary systems, providing valuable information on…
At intervals as short as ten thousand years, each white dwarf (WD) passes within a solar radius of a planetoid, i.e., a comet, asteroid, or planet. Gravitational tidal forces tear the planetoid apart; its metal-rich debris falls onto the…