author={M. Jura},
  journal={The Astronomical Journal},
  pages={1785 - 1792}
  • M. Jura
  • Published 27 February 2008
  • Physics, Geology
  • The Astronomical Journal
Extrapolating from the solar system's asteroid belt, we propose that externally contaminated white dwarfs without an infrared excess may be experiencing continuous accretion of gas-phase material that is ultimately derived from the tidal destruction of multiple small asteroids. If this scenario is correct, then observations of metal-polluted white dwarfs may lead to determination of the bulk elemental compositions of ensembles of extrasolar minor planets. 

Figures from this paper

Circumstellar Disks at White Dwarfs: Observations

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

Discovery of Beryllium in White Dwarfs Polluted by Planetesimal Accretion

The element beryllium is detected for the first time in white dwarf stars. This discovery in the spectra of two helium-atmosphere white dwarfs was made possible only because of the remarkable

Circumstellar Debris and Pollution at White Dwarf Stars

The frequency of planetary debris around young white dwarfs

Context. Heavy metals in the atmospheres of white dwarfs are thought in many cases to be accreted from a circumstellar debris disk, which was formed by the tidal disruption of a rocky planetary body

Characterizing the Chemistry of Planetary Materials Around White Dwarf Stars

Planetary systems that orbit white dwarf stars can be studied via spectroscopic observations of the stars themselves. Numerous white dwarfs are seen to have accreted mostly rocky minor planets, the

Planetary Systems Around White Dwarfs

  • D. Veras
  • Physics, Geology
    Oxford Research Encyclopedia of Planetary Science
  • 2021
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


We present optical and infrared characterization of the polluted DAZ white dwarf GALEX J193156.8+011745. Imaging and spectroscopy from the ultraviolet to the thermal infrared indicate that this white

The Elemental Compositions of Extrasolar Planetesimals

  • M. Jura
  • Physics, Geology
    Proceedings of the International Astronomical Union
  • 2012
Abstract Evidence is now compelling that most externally-polluted white dwarfs derive their heavy atoms by accretion from asteroids – the building blocks of rocky planets. Optical and ultraviolet

Compositions of Planetary Debris around Dusty White Dwarfs

The photospheres of some white dwarfs (WDs) are “polluted” by accretion of material from their surrounding planetary debris. WDs with dust disks are often heavily polluted and high-resolution

Metal Pollution of the Solar White Dwarf by Solar System Small Bodies

White dwarfs (WDs) often show metal lines in their spectra, indicating accretion of asteroidal material. Our Sun is to become a WD in several gigayears. Here, we examine how the solar WD accretes



Carbon Deficiency in Externally Polluted White Dwarfs: Evidence for Accretion of Asteroids

Existing determinations show that n(C)/n(Fe) is more than a factor of 10 below solar in the atmospheres of three white dwarfs that appear to be externally polluted. These results are not easily

The astrophysics of cool white dwarfs

Externally Polluted White Dwarfs with Dust Disks

We report Spitzer Space Telescope photometry of 11 externally polluted white dwarfs. Of the nine stars for which we have IRAC photometry, we find that GD 40, GD 133, and PG 1015+161 each has an

A Dusty Disk around GD 362, a White Dwarf with a Uniquely High Photospheric Metal Abundance

Eighteen years after an infrared excess was discovered associated with the white dwarf G29-38, we report ground-based measurements (JHKsKL′N′) with millijansky-level sensitivity of GD 362 that show

Evolutionary calculations of carbon dredge‐up in helium envelope white dwarfs

It has been proposed that the presence of carbon in the mainly helium atmospheres of the DQ white dwarfs is due to convective dredge-up of carbon diffusing outwards from a CO core. The first

Excess Infrared Radiation from the Massive DAZ White Dwarf GD 362: A Debris Disk?

We report the discovery of excess K-band radiation from the massive DAZ white dwarf star GD 362. Combining infrared photometric and spectroscopic observations, we show that the excess radiation

A study of metal abundance patterns in cool white dwarfs. II - Simulations of accretion episodes

Time-dependent simulations of episodic accretion of metals onto cool white dwarfs are presented. Calculations are made for Mg, Si, Ca, and Fe in H-rich and He-rich white dwarf models having a mass of

Element abundances in cool white dwarfs - II. Ultraviolet observations of DZ white dwarfs

We present a small data base of homogeneously derived photospheric element abundances of DZ white dwarfs and related objects. Our previous investigations are supplemented with the analysis of

The accretion-diffusion scenario for metals in cool white dwarfs

We calculated diffusion timescales for Ca, Mg, Fe in hydrogen atmosphere white dwarfs with temperatures between 5000 and 25 000 K. With these timescales we determined accretion rates for a sample of

Infrared Emission from the Dusty Disk Orbiting GD 362, an Externally Polluted White Dwarf

We report Spitzer Space Telescope photometry between 3.6 and 24 μm and spectroscopy between 5 and 15 μm of GD 362, a white dwarf with an effective temperature near 10,000 K that displays a remarkably