Related papers: Exoplanet recycling in massive white-dwarf debris …
Several white dwarfs with atmospheric metal pollution have been found to host small planetary bodies (planetesimals) orbiting near the tidal disruption radius. We study the physical properties and dynamical origin of these bodies under the…
Observational evidence of white dwarf planetary systems is dominated by the remains of exo-asteroids through accreted metals, debris discs, and orbiting planetesimals. However, exo-planets in these systems play crucial roles as perturbing…
A significant fraction of white dwarfs (WDs) exhibit signs of ongoing accretion of refractory elements at rates $\sim10^3$--$10^7$ kg s$^{-1}$, among which, 37 WDs were detected to harbor dusty debris disks. Such a concurrence requires not…
The lifetime of a planetary disc which orbits a white dwarf represents a crucial input parameter into evolutionary models of that system. Here we apply a purely analytical formalism to estimate lifetimes of the debris phase of these discs,…
The formation channel of the tens of compact debris discs which orbit white dwarfs (WDs) at a distance of one Solar radius remains unknown. Asteroids that survive the giant branch stellar phases beyond a few au are assumed to be dynamically…
Although discs of dust and gas have been observed orbiting white dwarfs, the origin of this circumstellar matter is uncertain. We hypothesize that the in-situ breakup of small bodies such as asteroids spun to fission during the giant branch…
The suite of over 60 known planetary debris discs which orbit white dwarfs, along with detections of multiple minor planets in these systems, motivate investigations about the migration properties of planetesimals embedded within the discs.…
Circumstellar disks of planetary debris are now known or suspected to closely orbit hundreds of white dwarf stars. To date, both data and theory support disks that are entirely contained within the preceding giant stellar radii, and hence…
We make use of a new hybrid method to simulate the long-term, multiple-orbit disc formation through tidal disruptions of rocky bodies by white dwarfs, at high-resolution and realistic semi-major axis. We perform the largest-yet suite of…
The gravitational instability model of planet/brown dwarf formation proposes that protostellar discs can fragment into objects with masses above a few Jupiter masses at large semimajor axis. Tidal downsizing may reduce both the object mass…
The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines…
25%-50% of all white dwarfs (WDs) host observable and dynamically active remnant planetary systems based on the presence of close-in circumstellar dust and gas and photospheric metal pollution. Currently-accepted theoretical explanations…
Observations of structure in circumstellar debris discs provide circumstantial evidence for the presence of massive planets at large (several tens of au) orbital radii, where the timescale for planet formation via core accretion is…
Observed planetary debris in white dwarf atmospheres predominately originate from the destruction of small bodies on highly eccentric ($>0.99$) orbits. Despite their importance, these minor planets have coupled physical and orbital…
Planetary systems commonly survive the evolution of single stars, as evidenced by terrestrial-like planetesimal debris observed orbiting and polluting the surfaces of white dwarfs. This letter reports the identification of a circumbinary…
Most stars are born in clusters and the resulting gravitational interactions between cluster members may significantly affect the evolution of circumstellar discs and therefore the formation of planets and brown dwarfs. Recent findings…
We investigate the interaction between an eccentric planet and a less massive external debris disc. This scenario could occur after planet-planet scattering or merging events. We characterise the evolution over a wide range of initial…
The migration of planets plays an important role in the early planet-formation process. An important problem has been that standard migration theories predict very rapid inward migration, which poses problems for population synthesis…
Giant planets in circumstellar disks can migrate inward from their initial (formation) positions. Radial migration is caused by inward torques between the planet and the disk; by outward torques between the planet and the spinning star; and…
Planetary material accreted by white dwarfs provides unique insights regarding exoplanetary composition. The evolutionary pathways of planetary bodies around white dwarfs are crucial to understanding the presence of close-in planetary…