Related papers: Measuring M dwarf Winds with DAZ White Dwarfs
Heavy elements are observed in the atmospheres of many DA and DB white dwarfs, and their presence is attributed to the accretion of matter coming from debris disks. Several authors have deduced accretion rates from the observed abundances,…
The accretion of tidally disrupted planetary bodies is the current consensus model for the presence of photospheric metals commonly detected in white dwarfs. While most dynamical studies have considered a single star and associated…
The atmospheres of a large proportion of white dwarf stars are polluted by heavy elements that are expected to sink out of visible layers on short timescales. This has been interpreted as a signature of ongoing accretion of debris from…
About 25-50% of white dwarfs (WDs) show metal lines in their spectra. Among the widely accepted explanations for this effect is that the these WDs are accreting asteroids that are perhaps flung onto the WDs by a planet via resonance, for…
This letter reports statistically significant changes in the equivalent widths of MgII and CaII lines in the dusty and polluted white dwarf WD 0106-328, based on six epochs of spectroscopy using the VLT and Keck spanning 25 yr. Furthermore,…
(Abridged) We present the results of the first unbiased survey for metal pollution among H-atmosphere (DA) white dwarfs with cooling ages of 20-200 Myr and 17000K < Teff < 27000K, using HST COS in the far UV between 1130 and 1435 A. The…
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…
Context: Luminosities of hot components in symbiotic binaries require accretion rates that are higher than those that can be achieved via a standard Bondi-Hoyle accretion. This implies that the wind mass transfer in symbiotic binaries has…
We perform numerical simulations to investigate high-power wind accretion in massive binary systems undergoing enhanced mass-loss episodes. The primary star is taken in the mass range $M_{1} = 60$--$90\,\mathrm{M_{\odot}}$, while the…
As stars evolve, they undergo significant changes in their physical properties, which can have a profound impact on the planets orbiting them. In particular, the mass lost through stellar wind may be partially accreted by orbiting planets.…
Accreting white dwarfs are known to show signatures of wind-type outflows in the ultraviolet. At optical wavelengths, however, wind detections have only been reported for a few sources. We present GTC-10.4m optical spectroscopy of four…
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…
White dwarf atmospheres are frequently polluted by material from their own planetary systems. Absorption features from Ca, Mg, Fe and other elements can provide unique insights into the provenance of this exoplanetary material, with their…
In this paper we propose and examine a physical mechanism which can lead to the generation of noise in the mass accretion rate of low mass X-ray binaries on time-scales comparable to the orbital period of the system. We consider modulations…
A significant fraction of white dwarfs show metal lines indicative of pollution with planetary material but the accretion process remains poorly understood. The main aim of this paper is to produce a road-map illustrating several potential…
Observations of planetary material polluting the atmospheres of white dwarfs are an important probe of the bulk composition of exoplanetary material. Medium- and high-resolution optical and ultraviolet spectroscopy of seven white dwarfs…
We present a study of the statistical flare rates of M dwarfs (dMs) with close white dwarf (WD) companions (WD+dM; typical separations < 1 au). Our previous analysis demonstrated that dMs with close WD companions are more magnetically…
We have investigated the mass accretion rate implied by published surface abundances of Si and C in the white dwarf component of the 3.62 hr period pre-cataclysmic binary and planet host candidate QS Vir (DA+M2-4). Diffusion timescales for…
We present numerical hydrodynamical modeling of the effects of a giant planet or brown dwarf companion orbiting within the extended atmosphere and wind formation zone of an approximately solar-mass Mira variable star. The large-scale,…
We calculate the stellar evolution of both white dwarfs (WDs) in AM CVn binaries with orbital periods of $P_{\mathrm{orb}} \approx 5-70$ minutes. We focus on the cases where the donor starts as a $M_{\mathrm{He}} < 0.2 \, M_{\odot}$ Helium…