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Related papers: CV evolution: AM Her binaries and the period gap

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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

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…

Solar and Stellar Astrophysics · Physics 2018-11-28 C. Garraffo , J. J. Drake , J. D. Alvarado-Gomez , S. P. Moschou , O. Cohen

The white dwarf in AM Her systems is strongly magnetic and keeps in synchronous rotation with the orbit by magnetic coupling to the secondary star. As the latter evolves through mass loss to a cool, degenerate brown dwarf it can no longer…

Astrophysics · Physics 2009-10-31 F. Meyer , E. Meyer-Hofmeister

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

Context. The evolution of cataclysmic variables (CVs) - interacting binaries where a low-mass donor transfers matter to a white dwarf via an accretion disk - is critically controlled by magnetic braking (MB). Significant uncertainties…

Solar and Stellar Astrophysics · Physics 2026-02-06 Bingyao Zhou , Chunhua Zhu , Guoliang Lü , Sufen Guo , Helei Liu , Farkhodjon Khamrakulov

A central hypothesis in the theory of cataclysmic variable (CV) evolution is the need to explain the observed lack of accreting systems in the ~2-3 h orbital period range, known as the period gap. The standard model, disrupted magnetic…

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

Magnetic wind braking drives the spin-down of low-mass stars and the evolution of most interacting binary stars. A magnetic braking prescription that was claimed to reproduce both the period distribution of cataclysmic variables (CVs) and…

Solar and Stellar Astrophysics · Physics 2024-10-10 Valentina Ortúzar-Garzón , Matthias R. Schreiber , Diogo Belloni

Recently, large and homogeneous samples of cataclysmic variables (CVs) identified by the Sloan Digital Sky Survey (SDSS) were published. In these samples, the famous orbital period gap, which is a dearth of systems in the orbital period…

Solar and Stellar Astrophysics · Physics 2024-02-06 Matthias R. Schreiber , Diogo Belloni , Axel D. Schwope

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

We model cataclysmic variables (CVs) with solar metallicity donors ($X=0.7,\:Z=0.02$) that evolve to form AM CVn stars through the Evolved CV formation channel using various angular momentum loss mechanisms by magnetic braking…

Solar and Stellar Astrophysics · Physics 2023-02-02 Arnab Sarkar , Hongwei Ge , Christopher A. Tout

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…

Solar and Stellar Astrophysics · Physics 2015-03-17 Christian Knigge

In this paper we study the impact of chemically evolved secondaries on CV evolution. We find that when evolved secondaries are included a spread in the secondary mass-orbital period plane comparable to that seen in the data is produced for…

Astrophysics · Physics 2009-11-10 N. Andronov , M. H. Pinsonneault

Mass transfer in cataclysmic variables (CVs) is usually considered to be caused by angular momentum loss (AML) driven by magnetic braking and gravitational radiation (GR) above the period gap, and solely by GR below the period gap. The…

Solar and Stellar Astrophysics · Physics 2015-05-30 Yong Shao , Xiang-Dong Li

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

I review our current understanding of the evolution of cataclysmic variables (CVs). I first provide a brief introductory "CV primer", in which I describe the physical structure of CVs, as well as their astrophysical significance. The main…

Solar and Stellar Astrophysics · Physics 2011-09-05 Christian Knigge

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 cataclysmic variables (CVs), including those which form with a brown dwarf…

Astrophysics · Physics 2009-10-31 Ulrich Kolb , Isabelle Baraffe

We give an updated version of the analytical equation of state used in the Cambridge stellar evolution code (STARS) as a free to use open-source package that we have used to model cool white dwarfs down to temperatures…

Solar and Stellar Astrophysics · Physics 2022-04-29 Arnab Sarkar , Christopher A. Tout

Context. For decades, reproducing the orbital period distribution of non-magnetic Cataclysmic Variables (CVs) seemed to require a drastic decrease, usually termed disruption, of angular momentum loss through magnetic braking at the fully…

Solar and Stellar Astrophysics · Physics 2026-04-15 Joaquín A. Barraza-Jorquera , Matthias R. Schreiber , Stuart Littlefair , Diogo Belloni , Axel D. Schwope

We apply the angular momentum loss rates inferred from open cluster stars to the evolution of cataclysmic variables (CVs). We show that the angular momentum prescriptions used in earlier CV studies are inconsistent with the measured…

Astrophysics · Physics 2009-11-06 N. Andronov , M. Pinsonneault , A. Sills
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