Related papers: White Dwarf Heating and Subsequent Cooling in Dwar…
We examine the properties of white dwarfs (WDs) accreting hydrogen-rich matter in and near the stable burning regime of accretion rates as modeled by time-dependent calculations done with Modules for Experiments in Stellar Astrophysics…
White dwarfs experience a thermal renaissance when they receive mass from a stellar companion in a binary. For accretion rates < 10^-8 Msun/yr, the freshly accumulated hydrogen/helium envelope ignites in a thermally unstable manner that…
In recent years several Dwarf Novae (DN) systems have been observed in quiescence, when the accretion rate is low and the WD photosphere can be directly detected. The WDs are observed to cool after the DN outburst from high effective…
We present the last HST/STIS E140M FUV spectrum (1150-1725A) of the dwarf nova (DN) WZ Sge, obtained in July 2004, 3 years following the early superoutburst of July 2001. Single white dwarf (WD) synthetic spectral fits (log{g}=8.5) to the…
Our previous theoretical study of the impact of an accreting envelope on the thermal state of an underlying white dwarf (WD) has yielded equilibrium core temperatures, classical nova ignition masses and thermal luminosities for WDs…
We explain the physics of compressional heating of the deep interior of an accreting white dwarf (WD) at accretion rates low enough so that the accumulated hydrogen burns unstably and initiates a classical nova (CN). In this limit, the WD…
FUSE and HST/STIS spectra of the dwarf nova WZ Sge, obtained during and following the early superoutburst of July 2001 over a time span of 20 months, monitor changes in the components of the system during its different phases. The synthetic…
We consider the behavior of matter in the accretion column that emerges under accretion in binary systems near the surface of a white dwarf. The plasma heated in a standing shock wave near the white dwarf surface efficiently radiates in the…
We show that irradiation of the accretion disc by the white dwarf limits the occurrence of dwarf nova outbursts in post nova accretion discs. After the nova explosion, the white dwarf has to cool for up to ~100 yr - depending on the orbital…
We have used FUSE to obtain thirteen observations of the dwarf nova VW Hyi covering the period from the end of a superoutburst through the following normal outburst of the system. Here, we present the quiescent spectra. They contain at…
We present dynamically consistent solutions for hot accretion onto unmagnetized, rotating white dwarfs (WDs) in five quiescent dwarf novae. The measured WD rotation rates (and other system parameters) in RX And, SS Cyg, U Gem, VW Hyi and WZ…
Following the pulsation spectrum of a white dwarf through the heating and cooling involved in a dwarf nova outburst cycle provides a unique view of the changes to convective driving that take place on timescales of months versus millenia…
When a white dwarf (WD) is weakly magnetized and its accretion disk is thin, accreted material first reaches the WD's surface at its equator. This matter slows its orbit as it comes into co-rotation with the WD, dissipating kinetic energy…
We calculate the effect of illumination of dwarf nova accretion discs by radiation from a hot, central, white dwarf. We show that only for very hot white dwarfs (Teff ~ 40 000$ K) the inner region of quiescent dwarf nova discs are partially…
We present time-dependent nova outburst models with optically thick winds for a 1.2 and 1.35 $M_\odot$ white dwarfs (WDs) with a mass accretion rate of $5 \times 10^{-9}~M_\odot$ yr$^{-1}$ and for a 1.3 $M_\odot$ WD with $2 \times…
We present a 904-1183 A spectrum of the dwarf nova VW Hydri taken with the Far Ultraviolet Spectroscopic Explorer during quiescence, eleven days after a normal outburst, when the underlying white dwarf accreter is clearly exposed in the far…
The boundary layers of weakly-magnetized white dwarfs (WDs) accreting at rates <=10^16 g/s are radially extended, hot, optically-thin, and they advect some of their internally-dissipated energy (Narayan & Popham 1993). Motivated by this, I…
A number of cool white dwarfs with metal traces, of spectral types DAZ, DBZ, and DZ have been found to exhibit infrared excess radiation due to circumstellar dust. The origin of this dust is possibly a tidally disrupted asteroid that formed…
Fluctuations during a prolonged maximum have been observed in several nova eruptions, although it is not clear, and can not be deduced directly from observations, if the phenomenon is an actual physical reaction to some mechanism…
Multicycle nova evolution models have been calculated over the past twenty years, the number being limited by numerical constraints. Here we present a long-term evolution code that enables a continuous calculation through an unlimited…