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Related papers: The CV period gap: still there

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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

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…

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 color-magnitude diagram of the lower main sequence, as measured from a volume-limited sample of nearby stars, shows an abrupt downward jump between Mv = 12 and 13. This jump indicates that the observed mass-radius relationship steepens…

Astrophysics · Physics 2009-10-30 J. Christopher Clemens , I. Neill Reid , John E. Gizis , M. Sean O'Brien

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…

Astrophysics · Physics 2011-05-05 Steve B. Howell , Lorne A. Nelson , Saul Rappaport

We apply the new generation of theoretical models of low-mass stars to secondaries in CVs, focussing on systems above the period gap. The models confirm that the spectral type should be a good indicator of the donor mass. The orbital…

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

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 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

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 investigate if consequential angular momentum losses (CAML) or an intrinsic deformation of the donor star in CVs could increase the CV bounce period from the canonical theoretical value ~65 min to the observed value $P_{min} \approx77$…

Astrophysics · Physics 2009-11-07 J. Barker , U. C. Kolb

We consider an alternative to the standard picture of CV and LMXB evolution, namely the idea that most CVs (and by extension LMXBs) may not yet have had time to evolve to their theoretical minimum orbital periods. We call this the Binary…

Astrophysics · Physics 2007-05-23 Andrew R. King , Klaus Schenker

The standard picture of CV secular evolution predicts a spike in the CV distribution near the observed short-period cutoff P_0 ~ 78 min, which is not observed. We show that an intrinsic spread in minimum (`bounce') periods P_b resulting…

Astrophysics · Physics 2009-11-07 A. R. King , K. Schenker , J. M. Hameury

I discuss population synthesis methods in the context of low-mass compact binaries. Two examples, both constraining the largely unknown strength of orbital angular momentum losses, illustrate the power and problems of such studies. For CVs,…

Astrophysics · Physics 2007-05-23 Ulrich Kolb

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

We have observed several magnetic cataclysmic variables located in the range between 2 and 3 hours, known as the period gap. This work was prompted by the recent discovery of RX J1554.2+2721. It has 2.54 hours orbital period and shows…

Astrophysics · Physics 2007-05-23 G. Tovmassian , S. Zharikov , R. Mennickent , J. Greiner

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

Archival data on permanent superhump systems are compiled to test the thermal stability of their accretion discs. We find that their discs are almost certainly thermally stable as expected. This result confirms Osaki's suggestion (1996)…

Astrophysics · Physics 2009-10-31 A. Retter , T. Naylor

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…

Astrophysics · Physics 2009-11-07 R. F. Webbink , D. T. Wickramasinghe

We report the results of a statistical study of cyclical period changes in cataclysmic variables (CVs). Assuming the third-body hypothesis as the cause of period changes, we estimate the third-body mass, $m_3$, and its separation from the…

Solar and Stellar Astrophysics · Physics 2024-08-16 Leandro Souza , Raymundo Baptista

We review the properties of the currently known CV population from an accountants point of view. In particular, it is examined to what extent different selection mechanisms (variability, X-ray emission, colours, spectroscopic properties)…

Astrophysics · Physics 2007-05-23 B. T. Gaensicke
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