Related papers: Exomoons as sources of white dwarf pollution
Do white dwarfs host asteroid systems? Although several lines of argument suggest that white dwarfs may be orbited by large populations of asteroids, transits would provide the most direct evidence. We demonstrate that the Kepler mission…
Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the DA white dwarf…
The emission of hard X-rays associated with white dwarfs (WD) can be generated by the presence of a stellar companion either by the companion's coronal emission or by an accretion disk formed by material stripped from the companion. Recent…
Only a handful of gas giant planets orbiting white dwarfs are known. It remains unclear whether this paucity reflects observational challenges or the consequences of stellar evolution. We aim to carry out population synthesis of substellar…
Between 30 - 50% of white dwarfs (WDs) show heavy elements in their atmospheres. This "pollution" is thought to arise from the accretion of planetesimals perturbed by outer planet(s) to within the WD's tidal disruption radius. A small…
White dwarfs with a F, G or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterised in terms of orbital period and…
We recommend that the search for exoplanets around binary stars be extended to include X-ray binaries in which the accretor is a white dwarf, neutron star, or black hole. We present a novel idea for detecting planets bound to such mass…
The MIRI Exoplanets Orbiting White dwarfs (MEOW) Survey is a cycle 2 JWST program to search for exoplanets around dozens of nearby white dwarfs via infrared excess and direct imaging. In this paper, we present the detection of mid-infrared…
By analogy to Jovian radio emissions powered by the electromagnetic interaction between Jupiter and its moons, we propose that close magnetic-nonmagnetic white-dwarf pairs and white-dwarf planetary systems are strong radio sources. A simple…
Accretion of planetary material onto host stars may occur throughout a star's life. Especially prone to accretion, extrasolar planets in short-period orbits, while relatively rare, constitute a significant fraction of the known population,…
Almost every known planet host will evolve into a white dwarf, and the surviving planetary material will continue to orbit this stellar remnant. Asteroids perturbed onto star-grazing orbits will become disrupted, forming an accretion disk…
We have used the WGACAT to search for hard X-ray sources associated with white dwarfs (WDs) from the catalog of McCook & Sion (1999). We find 17 X-ray sources coincident with WDs showing significant hard X-ray emission at energies >0.5 keV.…
Ultraviolet and optical spectra of the hydrogen-dominated atmosphere white dwarf star G238-44 obtained with FUSE, Keck/HIRES, HST/COS, and HST/STIS reveal ten elements heavier than helium: C, N, O, Mg, Al, Si, P, S, Ca, and Fe. G238-44 is…
Infrared (IR) excess emission around white dwarfs (WDs) is commonly attributed to circumstellar debris disks and/or low-mass companions, providing a unique window into the evolution of planetary systems and binary evolution after the…
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…
We have searched for evidence for dust and gas disks at a sample of hot DA white dwarfs 20 000K < Teff < 50 000K, without success. Although their atmospheres are polluted with heavy elements, we cannot yet convincingly and conclusively show…
The current picture painted by the observations of circumstellar dust at white dwarfs, and the consequent atmospheric pollution, is of a surviving planetary system. This chapter recounts in detail both the discovery and empirical…
White dwarf planetary science is a rapidly growing field of research featuring a diverse set of observations and theoretical explorations. Giant planets, minor planets, and debris discs have all been detected orbiting white dwarfs. The…
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…
Mounting discoveries of debris discs orbiting newly-formed stars and white dwarfs (WDs) showcase the importance of modeling the long-term evolution of small bodies in exosystems. WD debris discs are in particular thought to form from very…