English
Related papers

Related papers: Stellar models of evolved secondaries in CVs

200 papers

The evolution of low-mass contact binaries is influenced by angular-momentum loss, mass and energy transfer, and the nuclear evolution of the components. They have periods shorter than one day, and we expect their period evolution to be…

Solar and Stellar Astrophysics · Physics 2025-10-22 Matthias Fabry , Andrej Prša

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…

Astrophysics · Physics 2009-11-13 Magaretha L. Pretorius , Christian Knigge

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…

Solar and Stellar Astrophysics · Physics 2019-12-25 Diogo Belloni , Matthias R. Schreiber , Anna F. Pala , Boris T. Gänsicke , Mónica Zorotovic , Claudia V. Rodrigues

Magnetic braking causes the spin-down of single stars as they evolve on the main sequence. Models of magnetic braking can also explain the evolution of close binary systems, including cataclysmic variables. The well-known period gap in the…

Solar and Stellar Astrophysics · Physics 2012-02-24 G. A. J. Hussain

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,…

Solar and Stellar Astrophysics · Physics 2015-12-11 Matthias R. Schreiber , Monica Zorotovic , Thomas P. G. Wijnen

We present the results of the study of cataclysmic variables (CVs) and AM Canum Venaticorum (AM CVn) stars with our double dynamo (DD) formalism of angular momentum loss (AML) by magnetic braking (MB). We show that (1) our MB model…

Solar and Stellar Astrophysics · Physics 2024-01-09 Arnab Sarkar , Hongwei Ge , Lev Yungelson , Christopher A. Tout

Using improved, up-to-date stellar input physics tested against observations of low-mass stars and brown dwarfs we calculate the secular evolution of low-mass donor CVs, including those which form with a brown dwarf donor star. Our models…

Astrophysics · Physics 2007-05-23 Ulrich Kolb , Isabelle Baraffe

Context. Recent observations of close detached eclipsing M and K dwarf binaries have provided substantial support for magnetic saturation when stars rotate sufficiently fast, leading to a magnetic braking (MB) torque proportional to the…

Solar and Stellar Astrophysics · Physics 2023-11-09 Diogo Belloni , Matthias R. Schreiber , Maxwell Moe , Kareem El-Badry , Ken J. Shen

We resume the discussion about irradiation-driven mass transfer cycles in semi- detached compact binary systems. The analytical model that describes the onset of these cycles, which occur on a thermal timescale of the donor star, is…

Astrophysics · Physics 2009-11-10 A. Büning , H. Ritter

The distribution of secondary star masses in present-day post-common envelope binaries (PCEBs) is calculated using four different models for angular momentum loss (AML) during the post-CE phase: only gravitational radiation (GR), GR +…

Astrophysics · Physics 2009-11-11 Michael Politano , Kevin P. Weiler

Period bouncers are cataclysmic variables (CVs) that have evolved past their orbital period minimum. The strong disagreement between theory and observations of the relative fraction of period bouncers is a severe shortcoming in the…

Solar and Stellar Astrophysics · Physics 2024-06-21 Arnab Sarkar , Antonio C. Rodriguez , Sivan Ginzburg , Lev Yungelson , Christopher A. Tout

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…

Solar and Stellar Astrophysics · Physics 2016-11-23 Monica Zorotovic , Matthias Schreiber

We reconstruct the evolutionary path followed by cataclysmic variables (CVs) from the observed mass-radius relationship of their donor stars. Along the way, we update the semi-empirical CV donor sequence of Knigge (2006) and present a…

Solar and Stellar Astrophysics · Physics 2015-05-27 Christian Knigge , Isabelle Baraffe , Joseph Patterson

We critically re-examine the available data on the spectral types, masses and radii of the secondary stars in cataclysmic variables (CVs) and low-mass X-ray binaries (LMXBs), using the new catalogue of Ritter & Kolb (1998) as a starting…

Astrophysics · Physics 2009-10-30 D. A. Smith , V. S. Dhillon

The overwhelming majority of CVs have orbital periods shorter than 10 hr. However, a few have much longer periods, and their formation and existence pose challenges for the CV evolution models. These extremely long-period CVs must host…

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…

Astrophysics · Physics 2009-11-13 P. J. Davis , U. Kolb , B. Willems , B. T. Gänsicke

We present a model for the rotational evolution of a young, solar-mass star interacting magnetically with an accretion disk. As in a previous paper (Paper I), the model includes changes in the star's mass and radius as it descends the…

Solar and Stellar Astrophysics · Physics 2015-06-03 Sean P. Matt , Giovanni Pinzon , Thomas P. Greene , Ralph E. Pudritz

(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…

Secondary stars in cataclysmic variables (CVs) follow a well defined period-density relation. Thus, canonical donor stars in CVs are generally low-mass stars of spectral type M. However, several CVs have been observed containing secondary…

Solar and Stellar Astrophysics · Physics 2015-06-19 A. Rebassa-Mansergas , S. G. Parsons , C. M. Copperwheat , S. Justham , B. T. Gaensicke , M. R. Schreiber , T. R. Marsh , V. S. Dhillon

Although the theory of cataclysmic variable (CV) evolution is able to explain several observational aspects, strong discrepancies have existed for decades between observations and theoretical predictions of the orbital period distribution,…

Solar and Stellar Astrophysics · Physics 2019-09-30 Monica Zorotovic , Matthias R. Schreiber