Related papers: A white dwarf accreting planetary material determi…
The accretion of rocky material is responsible for the presence of heavy elements in the atmospheres of a large fraction of white dwarf stars. Those objects represent a unique opportunity to infer the bulk composition of exoplanetesimals.…
White dwarfs are the end state of most stars, including the Sun, after they exhaust their nuclear fuel. Between 1/4 and 1/2 of white dwarfs have elements heavier than helium in their atmospheres, even though these elements should rapidly…
This paper presents combined ${\it Spitzer}$ IRAC and ${\it Hubble}$ COS results for a double-blind survey of 195 single and 22 wide binary white dwarfs for infrared excesses and atmospheric metals. The selection criteria include cooling…
Recent infrared observations have revealed presence of compact (radii < R_Sun) debris disks around more than a dozen of metal-rich white dwarfs (WD), likely produced by tidal disruption of asteroids. Accretion of high-Z material from these…
Observations of heavy metal pollution in white dwarf stars indicate that metal-rich planetesimals are frequently scattered into star-grazing orbits, tidally disrupted, and accreted onto the white dwarf surface, offering direct insight into…
The timing of formation for the first planetesimals determines the mode of planetary accretion and their geophysical and compositional evolution. Astronomical observations of circumstellar discs and Solar System geochronology provide…
There is overwhelming evidence that white dwarfs host planetary systems; revealed by the presence, disruption, and accretion of planetary bodies. A lower limit on the frequency of white dwarfs that host planetary material has been estimated…
We present new XSHOOTER spectra of NLTT5306, a 0.44 $\pm$ 0.04\msun white dwarf in a short period (101\,min) binary system with a brown dwarf companion that is likely to have previously undergone common envelope evolution. We have confirmed…
The evolution of the magnetic field of an accreting magnetic white dwarf with an initially dipolar field at the surface has been studied for non-spherical accretion under simplifying assumptions. Accretion on to the polar regions tends to…
The accretion of planetary debris into the atmospheres of white dwarfs leads to the presence of metal lines in their spectra. Cool metal-rich white dwarfs, which left the main-sequence many Gyr ago, allow the study of the remnants of the…
Spitzer Space Telescope IRAC 3-8 micron and AKARI IRC 2-4 micron photometry are reported for ten white dwarfs with photospheric heavy elements; nine relatively cool stars with photospheric calcium, and one hotter star with a peculiar high…
Accreting white dwarfs are often found in close binary systems with orbital periods ranging from tens of minutes to several hours. In most cases, the accretion process is relatively steady, with significant modulations only occurring on…
This paper extends our previous study of planet/brown dwarf accretion by giant stars to solar mass stars located on the red giant branch. The model assumes that the planet is dissipated at the bottom of the convective envelope of the giant…
Recent observations of a large number of DA and DB white dwarfs show evidence of debris disks, which are the remnants of old planetary systems. The infrared excess detected with \emph{Spitzer} and the lines of heavy elements observed in…
In binary systems, the helium accretion onto carbon-oxygen (CO) white dwarfs (WDs) plays a vital role in many astrophysical scenarios, especially in supernovae type Ia. Moreover, ignition density for accretion rate $\dot{M} \lesssim 10^{-9}…
The iPTF detection of the most recent outburst of the recurrent nova system RX J0045.4+4154 in the Andromeda Galaxy has enabled the unprecedented study of a massive ($M>1.3\ M_\odot$) accreting white dwarf (WD). We detected this nova as…
We study C/O white dwarfs with masses of 1.0 to 1.4 Msun accreting solar-composition material at very high accretion rates. We address the secular changes in the WDs, and in particular, the question whether accretion and the thermonuclear…
The nature of the accreting companion to Mira --- the prototypical pulsating asymptotic giant branch star --- has been a matter of debate for more than 25 years. Here we use a quantitative analysis of the rapid optical brightness variations…
We present the Planetary Enriched White Dwarf Database (PEWDD), a collection of published photospheric abundances of white dwarfs accreting planetary debris alongside additional information relevant to metal-enrichment and the presence of…
Mass transfer from an evolved donor star to its binary companion is a standard feature of stellar evolution in binaries. In wide binaries, the companion star captures some of the mass ejected in a wind by the primary star. The captured…