scholarly journals Non-Conservative Evolution of Binary Stars

2011 ◽  
Vol 7 (S282) ◽  
pp. 417-424 ◽  
Author(s):  
Christopher A. Tout
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Stellar Wind ◽  
Binary Stars ◽  
Total Mass ◽  
Accretion Disc ◽  
Strong Wind ◽  
Common Envelope ◽  
Conservative Evolution

AbstractVarious processes can lead to non-conservative evolution in binary stars. Under conservative mass transfer, both the total mass and the orbital angular momentum of the system are conserved. Thus, the transfer of angular momentum between the orbit and the spins of the stars can represent one such effect. Stars generally lose mass and angular momentum in a stellar wind so, even with no interaction, evolution is non-conservative. Indeed, a strong wind can actually drive mass transfer. During Roche lobe overflow itself, mass transfer becomes non-conservative when the companion cannot accrete all the material transferred by the donor. In some cases, material is simply temporarily stored in an accretion disc. In others, the companion may swell up and initiate common envelope evolution. Often the transferred material carries enough angular momentum to spin the companion up to break-up, at which point it could not accrete more. We investigate how this is alleviated by non-conservative evolution.

5 Ceti: A Long-Period Binary Evolving Through Mass Exchange

1989 ◽  
Vol 106 ◽  
pp. 234-234
Author(s):  
Joel A. Eaton
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Mass Exchange ◽  
Main Sequence ◽  
Roche Lobe ◽  
Common Envelope ◽  
Long Period ◽  
Loss Of Mass

Binaries with very wide spearations are thought to evolve to small separations through a catastrophic form of mass exchange/loss known as common-envelope evolution. The theory of this process is fairly well developed, but proper tests remain elusive. Simply put, the theory argues that the rapidly shrinking Roche lobe of the mass losing giant will strip away the giant's main-sequence companion. Loss of mass from the system during the process carries away orbital angular momentum, thereby strengthening the effect.

scholarly journals Critical Mass for Merging in Double White Dwarfs

1989 ◽  
Vol 114 ◽  
pp. 450-453
Author(s):  
Izumi Hachisu ◽  
Mariko Kato
Keyword(s):  
Mass Transfer ◽  
Gravitational Radiation ◽  
White Dwarf ◽  
Binary Stars ◽  
White Dwarfs ◽  
Radiation Effect ◽  
Critical Mass ◽  
Mass Transfer Rate ◽  
Roche Lobe ◽  
Common Envelope

We examine whether or not double white dwarfs are ultimately merging into one body. It has been argued that such a double white dwarf system forms from some intermediate-mass binary stars and will merge due to the gravitational radiation which decreases the separation of binary. After filling the inner critical Roche lobe, the less massive component begins to transfer its mass to the more massive one. When the mass transfer rate exceeds a some critical value, a common envelope is formed. If the common envelope is hydrostatic, the mass transfer is tuned up to be a some value which depends only on the white dwarf mass, radius, and the Roche lobe size. The mass transfer from the less massive to the more massive components leads the separation to increase. On the other hand, the gravitational radiation effect reduces the separation. Which effect wins determines the fate of double white dwarfs, that is, whether merging or not merging. Since the formula of the gravitational radiation effect is well known, we have studied the mass accretion rate in common envelope phase of double white dwarfs assuming the Roche lobe size is as small as 0.03 R⊙ or 0.1 R⊙.

scholarly journals Evolution of binary stars with mass loss

1979 ◽  
Vol 83 ◽  
pp. 383-399
Author(s):  
Janusz Ziółkowski
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Binary Stars ◽  
Binary Systems ◽  
Close Binaries ◽  
Stellar Winds ◽  
Common Envelope ◽  
Weak Evidence ◽  
Orbital Periods ◽  
Detached Binaries

Three situations involving mass loss from binary systems are discussed. (1) Non-conservative mass exchange in semi-detached binaries. No quantitative estimate of this mechanism is possible at present. (2) Common envelope binaries. There are both theoretical and observational indications that this phase of evolution happens to many systems, even to some that are not very close initially (orbital periods ~ years). (3) Stellar winds in binaries. Observational evidence suggests that stellar winds from components of close binaries (especially semi-detached) are significantly stronger than from single stars at the same location in the H-R diagram. Theoretical arguments indicate that in some cases stellar wind may stabilize the component of a binary against the Roche lobe overflow. In some cases there is weak evidence of an anisotropy in the stellar wind.

scholarly journals Mass Loss in Algol-Type Stars: Implication on their Evolutionary Stage

1982 ◽  
Vol 69 ◽  
pp. 187-189
Author(s):  
F. Mardirossian ◽  
G. Giuricin
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Mass Loss ◽  
Observational Data ◽  
Mass Exchange ◽  
Total Mass ◽  
Evolutionary Stage ◽  
Momentum Loss ◽  
Evolutionary Scenario ◽  
Angular Momentum Loss

AbstractWe have examined the observational data of 102 Algols in order to clarify the implications on their evolutionary scenario of various assumptions concerning mass and angular momentum loss during mass transfer. We have found that case B mass exchange is strongly favoured for Algols of relatively low total mass (~ M < 7 Mʘ), while case A predominates, though not so widely as expected in Algols of higher total mass.

scholarly journals Fission and the Origin of Binary Stars

1970 ◽  
Vol 4 ◽  
pp. 147-156
Author(s):  
Jeremiah P. Ostriker
Keyword(s):  
Angular Momentum ◽  
Recent Work ◽  
Binary Stars ◽  
Total Mass ◽  
Binary Systems ◽  
Main Sequence ◽  
Rotating Stars ◽  
Early Type ◽  
Theoretical Predictions ◽  
Zero Viscosity

AbstractBrief reviews of the classical ‘angular momentum problem’ and the statistics of upper-main-sequence binaries are presented as background for the suggestion that the close, early-type, binaries are produced by fission of rapidly rotating protostars.Next, theoretical sequences of contracting, rotating stars are described. Recent work demonstrates that the zero-viscosity, polytropic sequences, have essentially the same properties as the McLaurin sequence. Thus, fission is possible for centrally condensed stars. Observations of close early-type binaries are compared with theoretical predictions for the minimum angular momentum in binary systems of given total mass; the agreement is excellent.Finally, the existing theoretical objections to the fission hypothesis for the origin of binary stars are reviewed, and it is concluded that, although fission remains unproven, there are now no strong theoretical arguments against the process, and there is considerable observational support for its existence.

scholarly journals Mass Transfer Characterization in Close Binary Stars

1992 ◽  
Vol 151 ◽  
pp. 337-340
Author(s):  
J. M. García ◽  
A. Giménez
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Binary Stars ◽  
Binary Star ◽  
Type System ◽  
Close Binary ◽  
Select Group ◽  
Close Binary Stars ◽  
Loss Of Mass ◽  
Close Binary Star

A method for estimating representative values of the parameters that characterize the loss of mass and angular momentum occurred during the evolution of a close binary star is considered. Absolute dimensions previous to mass-transfer stage have been obtained for a select group of 43 semidetached systems adopting a grid of values of mass loss, angular momentum loss and initial mass ratio. Our study reveals a highly non-conservative scenario for the evolution towards an Algol-type system.

scholarly journals Non conservative evolutionary scenario for 100 Algols

1981 ◽  
Vol 59 ◽  
pp. 473-475
Author(s):  
F. Mardirossian ◽  
G. Giuricin
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Observational Data ◽  
Mass Exchange ◽  
Strong Evidence ◽  
Total Mass ◽  
Momentum Loss ◽  
Evolutionary Scenario ◽  
Angular Momentum Loss ◽  
Low Mass

AbstractWe have examined the observational data of 100 Algols in order to check the validity of several simple models of non-conservative mass transfer. Strong evidence of mass and angular momentum loss has been found at least in about 20% of our Algols. Case B mass exchange is favoured for low-mass Algols, while case A predominates, though not so widely as expected, in Algols of higher total mass.

scholarly journals Energy and Angular Momentum Deposition During Common Envelope Evolution

2004 ◽  
Vol 194 ◽  
pp. 30-32
Author(s):  
Noam Soker
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Orbital Angular Momentum ◽  
White Dwarf ◽  
Early Stage ◽  
Mass Loss Rate ◽  
Orbital Energy ◽  
Giant Star ◽  
Common Envelope ◽  
The Common

AbstractI consider three processes which enhance mass loss rate from a common envelope of a giant star with a main sequence or a white dwarf companion spiraling-in inside its envelope. I consider deposition of orbital energy and orbital angular momentum to the giant's envelope, and the formation of jets by an accreting companion and their propagation in the envelope. I find that in many cases the deposition of orbital angular momentum to the envelope may be more important to the mass loss process than the deposition of orbital energy. Jets blown by an accreting companion, in particular a white dwarf, orbiting inside the outer regions of the giant's envelope may also dominate over orbital energy deposition at early stage of the common envelope evolution. These imply that, studies which ignore the deposition of angular momentum to the envelope and the effects of the accreting companion may reach wrong conclusions.

From dinuclear systems to close binary stars: Application to mass transfer

2018 ◽  
Vol 27 (07) ◽  
pp. 1850063 ◽  
Author(s):  
V. V. Sargsyan ◽  
H. Lenske ◽  
G. G. Adamian ◽  
N. V. Antonenko
Keyword(s):  
Mass Transfer ◽  
Binary Stars ◽  
Nuclear Physics ◽  
Total Mass ◽  
Close Binary ◽  
Stellar Systems ◽  
Star System ◽  
Mass Asymmetry ◽  
Symmetric Configuration ◽  
Close Binary Stars

Applying the microscopic nuclear physics ideas to macroscopic stellar systems, we study the evolution of the compact di-stars in mass asymmetry (transfer) coordinate. Depending on the internal structure of constituent stars, the initial mass asymmetry, total mass, and orbital angular momentum, the close di-star system can either exist in symmetric configuration or fuse into mono-star. The limitations for the formation of stable symmetric binary stars are analyzed.

scholarly journals On the Modeling of Algol-Type Binaries

Galaxies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 19
Author(s):  
Walter van van Rensbergen ◽  
Jean-Pierre de de Greve
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Angular Momentum ◽  
Mass Loss ◽  
Strong Magnetic Field ◽  
Stellar Wind ◽  
Orbital Parameters ◽  
Tidal Interaction ◽  
Magnetic Braking ◽  
Orbital Periods

In earlier papers, we presented a binary evolutionary code for the purpose of reproducing the orbital parameters, masses, radii, and location in the Hertzsprung Russell diagram (abbreviated as HRD) of well-observed Algol systems. In subsequent versions, the effects of mass and angular momentum losses and tidal coupling were included in order to produce the observed distributions of orbital periods and mass ratios of Algol-type binaries. The mass loss includes stellar wind and possible liberal evolution, when the gainer star is not capable to absorb all of the matter during mass transfer from the donor star. We added magnetic braking to our code to better reproduce the observed equatorial velocities. Large equatorial velocities of mass-gaining stars are now lowered by tidal interaction and magnetic braking. Tides are mainly at work at short orbital periods, leaving magnetic braking alone at work during longer orbital periods. The observed values of the equatorial velocities of mass gainers in Algol-type binaries are mostly well reproduced by our code. According to our models, Algols have short periods with a strong magnetic field.

Sign in / Sign up

Export Citation Format

Share Document