Related papers: White Dwarf Systems: the Composition of Exoplanets
Polluted white dwarfs offer a unique way to study the bulk compositions of exoplanetary material, but it is not always clear if this material originates from comets, asteroids, moons, or planets. We combine N-body simulations with an…
The search for extrasolar planets has developed rapidly and, today, more than 1700 planets have been found orbiting stars. Thanks to Gaia, we will collect high-accuracy astrometric orbits of thousands of new low-mass celestial objects, such…
The terrestrial and gas-giant planets in our solar system may represent some prototypes for planets around other stars; the exoplanets because most stars have similar overall elemental abundances as our sun. The solar system planets…
Understanding the formation, evolution, and chemical diversity of exoplanets are now central areas of astrophysics research. White dwarfs provide a uniquely sensitive laboratory for studying the end stages of planetary-system evolution and…
Thousands of extrasolar planets have been discovered, and it is clear that the galactic planetary census draws on a diversity greatly exceeding that exhibited by the solar system's planets. We review significant landmarks in the chronology…
We present a database of well determined orbital parameters of exoplanets. This database comprises spectroscopic orbital elements measured for 427 planets orbiting 363 stars from radial velocity and transit measurements as reported in the…
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…
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…
In the Solar System short-lived radioisotopes, such as 26Al, played a crucial role during the formation planetary bodies by providing a significant additional source of heat. Notably, this led to early and large-scale melting and iron core…
Previously published observations of 60 externally-polluted white dwarfs show that none of the stars have accreted from intact refractory-dominated parent bodies composed mainly of Al, Ca and O, although planetesimals with such a…
The present-day bulk elemental composition of an exoplanet can provide insight into a planet's formation and evolutionary history. Such information is now being measured for dozens of planets with state-of-the-art facilities using Bayesian…
The giant planet-metallicity correlation revealed that planetary formation depends on the stellar properties. There is growing evidence that it is also valid for smaller hot planets, but it is not clear whether elements other than iron also…
The last few years has seen a dramatic increase in the number of exoplanets known and in the range of methods for characterising their atmospheric properties. At the same time, new discoveries of increasingly cooler brown dwarfs have pushed…
In a previous study, we analysed the spectra of 230 cool ($T_\mathrm{eff}$ < 9000 K) white dwarfs exhibiting strong metal contamination, measuring abundances for Ca, Mg, Fe and in some cases Na, Cr, Ti, or Ni. Here we interpret these…
We present a critical review of the determination of fundamental parameters of white dwarfs discovered by the Gaia mission. We first reinterpret color-magnitude and color-color diagrams using photometric and spectroscopic information…
As the descendants of stars with masses less than 8 M$_{\odot}$ on the main sequence, white dwarfs provide a unique way to constrain planetary occurrence around intermediate-mass stars (spectral types BAF) that are otherwise difficult to…
We report the relative abundances of 17 elements in the atmosphere of the white dwarf star GD 362, material that, very probably, was contained previously in a large asteroid or asteroids with composition similar to the Earth/Moon system.…
The elemental compositions of exoplanets encode information about their formation environments and internal structures. While volatile ratios such as carbon-to-oxygen (C/O) are used to trace formation location, the rock-forming elements -…
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 indicates that the white dwarf hosts excess infrared emission…
Low-mass planets have an extraordinarily diverse range of bulk compositions, from primarily rocky worlds to those with deep gaseous atmospheres. As techniques for measuring the masses of exoplanets are advancing the field towards the…