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

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Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on…

Solar and Stellar Astrophysics · Physics 2019-08-14 V. Breus , K. Petrik , S. Zola

We present a new sample of $K$-band spectral observations for CVs: non-magnetic and magnetic as well as present day and pre CVs. The purpose of this diverse sample is to address the recent claim that the secondary stars in dwarf novae are…

Solar and Stellar Astrophysics · Physics 2015-05-18 Steve B. Howell , Thomas E. Harrison , Paula Szkody , Nicole M. Silvestri

Magnetic braking (MB) mechanism plays a vital role throughout the evolution of low-mass X-ray binaries (LMXBs). Considering the standard MB prescription, the initial orbital periods of LMXBs that can evolve into binary millisecond pulsar…

High Energy Astrophysical Phenomena · Physics 2025-11-11 Xing-Peng Yang , Wen-Cong Chen

The nova-like variable AE Aquarii is a close binary system containing a red dwarf and a magnetized white dwarf rotating with the period of 33 seconds. A short spin period of the white dwarf is caused by an intensive mass exchange between…

High Energy Astrophysical Phenomena · Physics 2015-06-19 N. G. Beskrovnaya , N. R. Ikhsanov

A systematic study on the long-term periodicities of known Galactic cataclysmic variables (CVs) was conducted. Among 1580 known CVs, 344 sources were matched and extracted from the Palomar Transient Factory (PTF) data repository. The PTF…

The present-day formation of cataclysmic variables (CVs) with brown dwarf (BD) secondaries (0.013 M_sun < M_sec < 0.075 M_sun) is investigated using a population synthesis technique. Results from the latest, detailed models for BDs have…

Astrophysics · Physics 2009-11-10 Michael Politano

Using photometric ULTRACAM observations of three new short period cataclysmic variables, we model the primary eclipse lightcurves to extract the orbital separation, masses, and radii of their component stars. We find donor masses of 0.060…

Orbital periods in AM Her stars (polars) are synchronized with spin periods of white dwarf by its high magnetic field. Since the last study of Porb distribution of these systems, the number of known objects of such type has more than…

Astrophysics · Physics 2010-05-28 Alex Golovin , Mykola Malygin , Elena Pavlenko

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 present results of our analysis of up to 15 years of photometric data from eight AM CVn systems with orbital periods between 22.5 and 26.8 min. Our data has been collected from the GOTO, ZTF, Pan-STARRS, ASAS-SN and Catalina all-sky…

According to standard evolutionary theory for cataclysmic variables (CVs), angular momentum loss drives CVs to initially evolve from longer to shorter orbital periods until a minimum period is reached (\approx 80 min). At roughly this…

Solar and Stellar Astrophysics · Physics 2011-05-09 Helena Uthas

The subclass of magnetic Cataclysmic Variables (CV), known as asynchronous polars, are still relatively poorly understood. An asynchronous polar is a polar in which the spin period of the white dwarf is either shorter or longer than the…

High Energy Astrophysical Phenomena · Physics 2021-07-08 Eric Masington , Thomas J. Maccarone , Liliana Rivera Sandoval , Craig Heinke , Arash Bahramian , Aarran Shaw

Observations of Cataclysmic Variables show a number of phenomena that do not fit easily into the standard magnetic braking scenario. These include the large spread in mass transfer rates, the low surface temperatures of many of the…

Astrophysics · Physics 2007-05-23 H. C. Spruit , R. E. Taam

The presence of a close, low-mass companion is thought to play a substantial and perhaps necessary role in shaping post-Asymptotic Giant Branch and Planetary Nebula outflows. During post-main-sequence evolution, radial expansion of the…

Solar and Stellar Astrophysics · Physics 2015-05-18 J. Nordhaus , D. S. Spiegel , L. Ibgui , J. Goodman , A. Burrows

We discuss the evolution of the magnetic field of an accreting white dwarf. We first show that the timescale for ohmic decay in the liquid interior is 8 to 12 billion years for a dipole field, and 4 to 6 billion years for a quadrupole…

Astrophysics · Physics 2009-11-07 Andrew Cumming

We report follow-up studies of 35 recently-discovered cataclysmic variables (CVs), 32 of which were found in large, automated synoptic sky surveys. The objects were selected for observational tractability. For 34 of the objects we present…

Solar and Stellar Astrophysics · Physics 2016-12-14 John R. Thorstensen , Erek H. Alper , Kathryn E. Weil

Cataclysmic variables undergo periodic nova explosions during which a finite mass of material is expelled on a short timescale. The system widens and, as a result, the mass-transfer rate drops. This state of hibernation may account for the…

Astrophysics · Physics 2008-11-26 Rebecca G. Martin , Christopher A. Tout

(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…

Using a recent Chandra ACIS observation of the eclipsing cataclysmic variable (CV) V1460 Her (2MASS J16211735+4412541) with a fast-rotating ($P_{\rm spin} = 38.9$~s) white dwarf, we estimated a flux $F_{0.5-7 {\rm keV}}^{\rm abs} = (1.9\pm…

Solar and Stellar Astrophysics · Physics 2025-01-08 Erik B. Monson , George G. Pavlov , Gordon P. Garmire

Recent observations show that the white dwarfs (WDs) in cataclysmic Variables (CVs) have an average mass significantly higher than isolated WDs and WDs in post-common envelope binaries (PCEBs), which are thought to the progenitors of CVs.…

Solar and Stellar Astrophysics · Physics 2016-12-07 Wei-Min Liu , Xiang-Dong Li