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 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 Comments on the Evolution and Origin of cataclysmic Binaries

1979 ◽  
Vol 53 ◽  
pp. 474-477
Author(s):  
Charles A. Whyte ◽  
Peter P. Eggleton
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Initial Conditions ◽  
Numerical Procedure ◽  
Classical Novae ◽  
Momentum Loss ◽  
Cataclysmic Binaries ◽  
Short Period ◽  
Angular Momentum Loss ◽  
Low Mass

AbstractSome aspects of the observational data on cataclysmic binaries are discussed and some possible correlations between type of behaviour and binary period are noted. A gap between 2 and 3 hours in the histogram of binary periods is estimated to be real. A numerical procedure for following the evolution of Roche-lobe-fiUing stars using simplified equations is described. This procedure Is applied to white/red dwarf binaries for a variety of initial conditions, and of mass loss and angular momentum loss mechanisms. The results of these calculations, in which we ignore the short timescale behaviour of the systems, are classified into four modes of evolution: normal, nuclear evolution dominated, angular momentum loss dominated and hydrodynamical. The results are discussed in connection with cataclysmic binaries. The clustering in period below 2 hours is Interpreted in terms of evolution following the hydrodynamical mode, and it is suggested that such systems contain low mass white dwarfs as well as low mass secondaries. These may be the most common type of cataclysmic binary. A possible explanation of the clustering of classical novae systems to binary periods of 3 to 5 hours is mentioned, and evolutionary scenarios for cataclysmic binaries are outlined. We suggest, following Ritter and Webbink, that the short period systems (≲ 2 hrs) arise mainly from late Case B mass transfer in the original binary (original primary mass 1.5 to 3M⊙) and the longer period systems arise mainly from Case C mass transfer.Full text to be published in Monthly Notices of the Royal Astronomical Society.

scholarly journals Gone with the wind: the impact of wind mass transfer on the orbital evolution of AGB binary systems

2018 ◽  
Vol 618 ◽  
pp. A50 ◽  
Author(s):  
M. I. Saladino ◽  
O. R. Pols ◽  
E. van der Helm ◽  
I. Pelupessy ◽  
S. Portegies Zwart
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Stellar Wind ◽  
Binary Systems ◽  
Orbital Evolution ◽  
Momentum Loss ◽  
Angular Momentum Loss ◽  
Wind Velocities ◽  
Low Mass ◽  
Orbital Periods

In low-mass binary systems, mass transfer is likely to occur via a slow and dense stellar wind when one of the stars is in the asymptotic giant branch (AGB) phase. Observations show that many binaries that have undergone AGB mass transfer have orbital periods of 1–10 yr, at odds with the predictions of binary population synthesis models. In this paper we investigate the mass-accretion efficiency and angular-momentum loss via wind mass transfer in AGB binary systems and we use these quantities to predict the evolution of the orbit. To do so, we perform 3D hydrodynamical simulations of the stellar wind lost by an AGB star in the time-dependent gravitational potential of a binary system, using the AMUSE framework. We approximate the thermal evolution of the gas by imposing a simple effective cooling balance and we vary the orbital separation and the velocity of the stellar wind. We find that for wind velocities higher than the relative orbital velocity of the system the flow is described by the Bondi-Hoyle-Lyttleton approximation and the angular-momentum loss is modest, which leads to an expansion of the orbit. On the other hand, for low wind velocities an accretion disk is formed around the companion and the accretion efficiency as well as the angular-momentum loss are enhanced, implying that the orbit will shrink. We find that the transfer of angular momentum from the binary orbit to the outflowing gas occurs within a few orbital separations from the centre of mass of the binary. Our results suggest that the orbital evolution of AGB binaries can be predicted as a function of the ratio of the terminal wind velocity to the relative orbital velocity of the system, v∞/vorb. Our results can provide insight into the puzzling orbital periods of post-AGB binaries. The results also suggest that the number of stars entering into the common-envelope phase will increase, which can have significant implications for the expected formation rates of the end products of low-mass binary evolution, such as cataclysmic binaries, type Ia supernovae, and double white-dwarf mergers.

scholarly journals High Mass Ratio Contact Binaries: Recent Evolution into Contact?

1989 ◽  
Vol 107 ◽  
pp. 348-349
Author(s):  
Bruce J. Hrivnak
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Primary Component ◽  
High Mass ◽  
Mass Ratio ◽  
Origin And Evolution ◽  
Momentum Loss ◽  
Angular Momentum Loss ◽  
Mass Ratios ◽  
Contact Binaries

Recent theories of the origin and evolution of contact binaries suggest that the two stars evolve into contact through angular momentum loss (AML; Mochnacki 1981, Vilhu 1982). When in contact, the system then evolves toward smaller mass ratio through mass transfer from the secondary to the primary component (Webbink 1976, Rahunen and Vilhu 1982). Most contact binaries have mass ratios of 0.3 to 0.5.

scholarly journals Stellar Evolution and Mass Transfer in Binaries

1993 ◽  
Vol 137 ◽  
pp. 807-809
Author(s):  
A.A. Bojarchuk ◽  
V.M. Chechetkin ◽  
O.A. Kuznetzov ◽  
Yu.P. Popov
Keyword(s):  
Mass Transfer ◽  
Computer Simulation ◽  
Angular Momentum ◽  
Stellar Evolution ◽  
Momentum Loss ◽  
Angular Momentum Loss

AbstractThe problem of angular momentum loss in binaries and its influence on stellar evolution is considered. The results of 2D hydrodynamics computer simulation of mass transfer is presented.

scholarly journals Formation and Evolution of Low-Mass Algols

1989 ◽  
Vol 107 ◽  
pp. 141-153
Author(s):  
L.R. Yungelson ◽  
A.V. Tutukov ◽  
A.V. Fedorova
Keyword(s):  
Angular Momentum ◽  
Gravitational Waves ◽  
Stellar Winds ◽  
Momentum Loss ◽  
Angular Momentum Loss ◽  
Low Mass ◽  
Formation And Evolution

AbstractWe discuss the origin, evolution and fate of low-mass Algols (LMA) that have components with initial masses less than 2.5 M0. The semi-major axes of orbits of pre-LMA do not exceed 20-25 R0. The rate of formation of Algol-type stars is ~ 0.01/year. Magnetic stellar winds may be the factor that determines the evolution of LMA. Most LMA end their lives as double helium degenerate dwarfs with M1/M2 ~ 0.88 (like L870-2). Some of them even merge through angular momentum loss caused by gravitational waves.

scholarly journals On the Evolutionary History of Progenitors of EHBs and Related Binary Systems from their Observed Properties

2006 ◽  
Vol 2 (S240) ◽  
pp. 678-681
Author(s):  
V.V. Pustynski ◽  
I. Pustylnik
Keyword(s):  
Angular Momentum ◽  
Binary Systems ◽  
Mass Loss Rate ◽  
Analytical Formula ◽  
Solar Mass ◽  
Momentum Loss ◽  
Angular Momentum Loss ◽  
History Of ◽  
Low Mass ◽  
Red Giant

AbstractIt has been shown quite recently (Morales-Rueda et al. 2003) that dB stars, extreme horizontal branch (EHB) objects in high probability all belong to binary systems. We study in detail the mass and angular momentum loss from the giant progenitors of sdB stars in an attempt to clarify why binarity must be a crucial factor in producing EHB objects. Assuming that the progenitors of EHB objects belong to binaries with initial separations of a roughly a hundred solar radii and fill in their critical Roche lobes while close to the tip of red giant branch, we have found that considerable shrinkage of the orbit can be achieved due to a combined effect of angular momentum loss from the red giant and appreciable accretion on its low mass companion on the hydrodynamical timescale of the donor, resulting in formation of helium WD with masses roughly equal to a half solar mass and thus evading the common envelope stage. A simple approximative analytical formula for mass loss rate from Roche lobe filling giant donor has been proposed depending on mass, luminosity and radius of donor.

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