Related papers: Pulsational Instabilities in Accreting White Dwarf…

Low-mass helium-core white-dwarfs (WDs) with masses below 0.5 Msun are known to be formed in binary star systems but unexpectedly a significant fraction of them seem to be single. On the other hand, in Cataclysmic Variables (CVs) a large…

We have extracted spectra of 20 magnetic Cataclysmic Variables (mCVs) from the RXTE archive and fitted them using the X-ray continuum method of Cropper et al to determine the mass of the accreting white dwarf in each system. We find…

Many isolated white dwarfs (WDs) show spectral evidence of atmospheric metal pollution. Since heavy element sedimentation timescales are short, this most likely indicates ongoing accretion. Accreted metals encounter a variety of mixing…

We present high-speed, three-colour photometry of the eclipsing cataclysmic variables GY Cnc, IR Com and HT Cas. We find that the sharp eclipses in GY Cnc and IR Com are due to eclipses of the white dwarf. There is some evidence for a…

Metals in the photospheres of white dwarfs with Teff between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1-2 weeks. Temporal variations in the line strengths of these metals could provide a direct…

AM CVn stars are ultra-compact semi-detached binaries consisting of a white dwarf primary and a hydrogen-depleted secondary. In this paper we present spectroscopic and photometric results of 15 transient sources pre-classified as AM CVn…

We use the new ZZ Ceti stars (hydrogen atmosphere white dwarf variables; DAVs) discovered within the Sloan Digital Sky Survey (Mukadam et al. 2004) to re-define the empirical ZZ Ceti instability strip. This is the first time since the…

I review what we know about the donor stars in cataclysmic variables (CVs), focusing particularly on the close link between these binary components and the overall secular evolution of CVs. I begin with a brief overview of the "standard…

Hydrogen-rich white dwarfs (WDs) comprise the majority of the WD population, but are only rarely found at the very hot end of the WD cooling sequence. A small subgroup that exhibits both hydrogen and helium lines in their spectra, the…

Interacting binaries in which a white dwarf accretes material from a companion --- cataclysmic variables (CVs) in which the mass loss is via Roche-lobe overflow, and symbiotic stars in which the white dwarf captures the wind of a late type…

Can a white dwarf, accreting hydrogen-rich matter from a non-degenerate companion star, ever exceed the Chandrasekhar mass and explode as a type Ia supernova? We explore the range of accretion rates that allow a white dwarf (WD) to…

The influence of the magnetic field on process of the accretion onto White Dwarfs in Cataclysmic Variables (CVs) is discussed. Except for the Polars or AM Her objects, the strength of magnetic field can not be measured directly in CVs by…

Radio emission from non-magnetic cataclysmic variables (CVs, accreting white dwarfs) could allow detailed studies of outflows and possibly accretion flows in these nearby, numerous and non-relativistic compact accretors. Up to now, however,…

Several hypervelocity white dwarfs (HVWDs) with space velocities of $\gtrsim 1000\,\mathrm{kms}^{-1}$ have recently been discovered. One possible origin of these stars is the dynamically-driven double-degenerate double-detonation (D6)…

We consider accretion onto the white dwarfs in cataclysmic variables in relation to nova eruptions, dwarf nova outbursts, hibernation and non-radial oscillations.

We present LAMOST J0140355+392651 (hereafter J0140), a close ($P_{\rm orb} = 3.81$ hours) binary containing a bloated, low-mass ($M \approx 0.15 M_{\odot}$) proto-white dwarf (WD) and a massive ($M\approx 0.95\,M_{\odot}$) WD companion. The…

We describe Chandra High-Energy Transmission Grating Spectrometer observations of RT Cru, the first of a new sub-class of symbiotic stars that appear to contain white dwarfs (WDs) capable of producing hard X-ray emission out to greater than…

I give an overview of the rich phenomenology of dwarf nova oscillations (DNOs) and Quasi-periodic Oscillations (QPOs) observed in cataclysmic variable stars (CVs). The favoured interpretation of these rapid brightness modulations (3 - >1000…

We present 16 new, and confirm 7 previously identified, DA white dwarfs in the Kepler field through ground-based spectroscopy with the Hale 200", Kitt Peak 4-meter, and Bok 2.3-meter telescopes. Using atmospheric models we determine their…

An HST COS Far UV spectrum (1170 A to 1800 A) was obtained for the short orbital period recurrent novae (T Pyxidis subclass), CI Aquilae. CI Aql is the only classical CV known to have two eclipses of sensible depth per orbit cycle and also…