Related papers: A unified model for the evolution of cataclysmic v…
One of the most important problems in the context of cataclysmic variables (CVs) is the lack of observations of systems with periods between 2 and 3.12 hours, known as the period gap. The orbital evolution of CVs with periods shorter than…
We present the first population synthesis of synchronous magnetic cataclysmic variables, called polars, taking into account the effect of the white dwarf (WD) magnetic field on angular momentum loss. We implemented the reduced magnetic…
We use an independent new sample of cataclysmic variables (CVs), constructed by selecting objects for Halpha emission, to constrain the properties of the intrinsic CV population. This sample is restricted to systems that are likely to be…
We extend a magnetic braking (MB) model, which has been used earlier to address the evolution of cataclysmic variables, to address the spin period $P_\mathrm{spin}$ evolution of fully convective M dwarf (FCMD) stars. The MB mechanism is an…
We present high-speed, three-colour photometry of the eclipsing cataclysmic variables CTCV 1300, CTCV 2354 and SDSS 1152. All three systems are below the observed "period gap" for cataclysmic variables. For each system we determine the…
Cataclysmic variables were long considered to be close binaries consisting of a white dwarf and a Roche-lobe-filling, near-zero-age main-sequence (ZAMS) red or brown dwarf. Recent massive surveys have uncovered an increasing number of…
Cataclysmic Variables (CV) are close binary systems, in which the primary, the more massive star, is a white dwarf. CVs usually exhibit a number of periodicities, most of which are now understood. However, recently, a new phenomenon was…
We report on the masses ($M_\mathrm{WD}$), effective temperatures ($T_\mathrm{eff}$) and secular mean accretion rates ($\langle \dot{M} \rangle$) of 43 cataclysmic variable (CV) white dwarfs, 42 of which were obtained from the combined…
AM Her variables -- synchronised magnetic cataclysmic variables (CVs) -- exhibit a different period distribution from other CVs across the period gap. We show that non-AM Her systems may infiltrate the longer-period end of the period gap if…
(Abridged) We present high-speed, three-colour photometry of seven short period (Porb <= 95 mins) eclipsing CVs from the Sloan Digital Sky Survey. We determine the system parameters via a parametrized model of the eclipse fitted to the…
We critically examine the basic paradigm for the origin of the 2-3 hr period gap in cataclysmic variables (CVs). We carry out an extensive population synthesis study of CVs starting from ~ 3 x 10^6 primordial binaries, and evolving some ~ 2…
We have performed a study of the orbital properties of seven eclipsing cataclysmic variable (CV) binary systems by analyzing photometric time series from the Transiting Exoplanet Survey Satellite (TESS). We employed Python code to determine…
Recent studies revealed discrepancies between observations and the predictions of the standard magnetic braking (MB). Although alternative models have been broadly discussed in neutron star binaries, they have not been systematically tested…
Cataclysmic variable (CVs) are close interacting binaries in which a white dwarf accretes materials from a low mass main sequence companion. CVs can experience nova eruptions due to low mass transfer rates. In the standard theory of CV…
Binary evolution theory predicts that accreting white dwarfs with sub-stellar companions dominate the Galactic population of cataclysmic variables (CVs). In order to test these predictions, it is necessary to identify these systems, which…
We present HST spectroscopy for 45 cataclysmic variables (CVs), observed with HST/COS and HST/STIS. For 36 CVs, the white dwarf is recognisable through its broad Ly$\alpha$ absorption profile and we measure the white dwarf effective…
The observed orbital period distribution of cataclysmic variables (CVs), the space density derived from observations, and the observed orbital period minimum are known to disagree with theoretical predictions since decades. More recently,…
The general prediction that more than half of all CVs have evolved past the period minimum is in strong disagreement with observational surveys, which show that the relative number of these objects is just a few per cent. Here, we…
Although a large number of orbital periods of cataclysmic variable stars (CVs) have been measured, comparison of period and luminosity distributions with evolutionary theory is affected by strong selection effects. A test has been…
We apply population synthesis techniques to calculate the present day number of two types of white dwarf-main sequence star (WDMS) binaries within the cataclysmic variable period gap. The first are post-common envelope binaries with…