Evolution Of Cataclysmic Binaries Research Articles

The mass and angular momentum loss from the edge of the accretion disk and the evolution of cataclysmic binaries

We give the mass and angular momentum loss from the edge of the accretion disk of a cataclysmic binary and model theoretically the effect of these losses on the evolution of the system. The results of the calculation show that the high-velocity mass outflows observed by IUE come from the edge of the disk and the angular momentum loss there could be the mechanism that drives the evolution of cataclysmic variables with periods longer than 3 hours.

Magnetic braking and the evolution of cataclysmic binaries

Magnetic braking and the evolution of cataclysmic binaries

Do novae hibernate during most of the millenia between eruptions? Links between dwarf and classical novae, and implications for the space densities and evolution of cataclysmic binaries

The effects of mass and angular momentum losses during a nova eruption are investigated by simulation in the context of a new nova evolution model. It is argued that surveys for cataclysmic variables (CVs) are very incomplete and that the local space density of CVs could well be 0.0001/cu pc. It is shown that the competing effets of mass and angular momentum loss usually increase the separation of a red and white dwarf during a nova eruption. The reasons why old novae remain bright for about a century after eruption and why they reduce the mass transfer rate (MTR) and eventually go into a state of hibernation for a thousand to a million years, eventually reviving as dwarf novae or novalike variables, are discussed. The results of these simulations are used to demonstrate the consistency of variable MTR in resolving the MTR discrepancy. 43 references.

A possible observational constraint on the production of lithium by galactic novae

Recent computations (D'Antona and Mazzitelli, 1982), together with the general scheme of evolution of cataclysmic binaries (CBs), lead to conclude that the secondaries in those CBs having periods shorter than ∼4.5 hr have a large3He content in the envelope, ranging from 10−4 (P=4.5 hr) to >2×10−3 (P=3 hr) in mass fraction, if the nova systems have an age of some billion years. The consequence on the frequency of novae outbursts is shortly examined. If lithium is produced by galactic novae, the7Li content of old disk stars should be very close to the Population II content.

The Origin and Evolution of Cataclysmic Binaries

ABSTRACTSome cataclysmic binaries may be products of Case C evolution of low mass stars (orbital period ~ 1 yr; masses ~ 1 - 4 Mʘ), involving a common envelope phase. Other mechanisms, probably involving late Case B and even early Case B, but with significant loss of angular momentum, may be necessary to account for some evolved binaries such as AA Dor or V Sge. Further angular momentum loss, probably by magnetic braking coupled with tidal friction, causes secular evolution in cataclysmic binaries. It is suggested that tidal friction may account for the shortage of cataclysmics with periods ≲ 1.3 hr; but this cutoff, as well as the gap in the period distribution between 2 and 3 hrs, is hard to explain and imposes more severe constraints on possible theories than is commonly acknowledged.

Secular evolution of cataclysmic binaries - Evolution of the secondary and the period gap

The evolution of low-mass main-sequence stars subject to mass loss at constant rates is followed, starting from several initial degrees of hydrogen depletion in the central regions and imposing several different rares of mass loss. During this evolution, stars of progressively smaller mass become fully convective. The behavior of convection along the computed sequences is a function both of the chemical stratification of the star and of the degree of departure from thermal equilibrium. Total mixing for stars initially not largely evolved occurs at Mapprox.0.4 M/sub sun/, and, according to the preceding history of the star, the mixing raises or decreases the /sup 3/He concentration in the core noticeably on a short time scale. The consequent sudden variation of the nuclear luminosity produces a thermal readjustment and a small radius increase or decrease. In more evolved initial models (central hydrogen mass fraction X/sub c/approx.0.30, toal mixing occurs only at Mapprox.0.2 M/sub sun/.

Gravitational radiation and the evolution of cataclysmic binaries

view Abstract Citations (35) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Gravitational radiation and the evolution of cataclysmic binaries. Taam, R. E. ; Flannery, B. P. ; Faulkner, J. Abstract Results are presented for several evolutionary sequences of close binary systems which resemble dwarf novae. The systems, containing white dwarfs and main-sequence companions, have masses less than 3.4 solar masses and periods less than 17 hours. The loss of angular momentum by gravitational radiation is included in the calculations. It is found that a system can be captured as a result of evolution dominated by gravitational radiation losses when the primary encounters its Roche lobe while near the main sequence. In such a case, the system evolves to even shorter periods, with the nuclear time scale of the primary increasing so that the latter is unable to exhaust hydrogen. Other sequences do not result in capture (1) when the primary is sufficiently evolved that it can exhaust hydrogen during mass exchange and (2) when a simple model for mass and angular momentum losses associated with nova outbursts from the accreting white dwarf is considered Publication: The Astrophysical Journal Pub Date: August 1980 DOI: 10.1086/158190 Bibcode: 1980ApJ...239.1017T Keywords: Binary Stars; Gravitational Waves; Stellar Evolution; Variable Stars; Angular Momentum; Dwarf Stars; Hydrogen; Novae; Stellar Mass Ejection; Astrophysics full text sources ADS | data products SIMBAD (5)

On the Masses and the Evolution of Cataclysmic Binaries

On the Masses and the Evolution of Cataclysmic Binaries

Masses and Evolution of Cataclysmic Binaries

The determination of masses and mass ratios of cataclysmic binaries is discussed. It is suggested that these systems started as wide binaries, which have lost substantial amounts of mass and still more substantial amounts of angular momentum.