scholarly journals Analytic post-Newtonian expansion of the energy and angular momentum radiated to infinity by eccentric-orbit nonspinning extreme-mass-ratio inspirals to the 19th order

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Christopher Munna
Keyword(s):  
Angular Momentum ◽  
Mass Ratio ◽  
Eccentric Orbit

Accretion of Mass and Spin Angular Momentum by a Planet on an Eccentric Orbit

Icarus ◽  
1997 ◽  
Vol 127 (1) ◽  
pp. 65-92 ◽  
Author(s):  
Jack J. Lissauer ◽  
Alice F. Berman ◽  
Yuval Greenzweig ◽  
David M. Kary
Keyword(s):  
Angular Momentum ◽  
Spin Angular Momentum ◽  
Eccentric Orbit

A Study of the Orbital and Intrinsic Variability of the Double-Lined Spectroscopic Binary β Centauri

2002 ◽  
Vol 185 ◽  
pp. 86-87
Author(s):  
M. Ausseloos ◽  
C. Aerts ◽  
K. Uytterhoeven
Keyword(s):  
High Resolution ◽  
Orbital Motion ◽  
High Signal ◽  
Mass Ratio ◽  
Eccentric Orbit ◽  
Intrinsic Variability ◽  
Signal To Noise ◽  
Orbital Parameters ◽  
Spectroscopic Binary ◽  
First Time

AbstractWe introduce our observational study of the orbital motion of β Cen. Using 463 high signal-to-noise, high-resolution spectra obtained over a timespan of 12 years it is shown that the radial velocity of β Cen varies with an orbital period of 357.0 days. We derive for the first time the orbital parameters of β Cen and find a very eccentric orbit (e = 0.81) and similar component masses with a mass ratio M1/M2 = 1.02. Both the primary and the secondary exhibit periodic line-profile variations.

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 Slowly, slowly in the wind

2019 ◽  
Vol 626 ◽  
pp. A68 ◽  
Author(s):  
M. I. Saladino ◽  
O. R. Pols ◽  
C. Abate
Keyword(s):  
Angular Momentum ◽  
Wind Velocity ◽  
Binary Systems ◽  
Asymptotic Giant Branch ◽  
Mass Ratio ◽  
Momentum Loss ◽  
Angular Momentum Loss ◽  
Mass Ratios ◽  
Type Ia ◽  
Particle Hydrodynamics

Wind mass transfer in binary systems with asymptotic giant branch (AGB) donor stars plays a fundamental role in the formation of a variety of objects, including barium stars and carbon-enhanced metal-poor (CEMP) stars. In an attempt to better understand the properties of these systems, we carry out a comprehensive set of smoothed-particle hydrodynamics (SPH) simulations of wind-losing AGB stars in binaries for a variety of binary mass ratios, orbital separations, initial wind velocities, and rotation rates of the donor star. The initial parameters of the simulated systems are chosen to match the expected progenitors of CEMP stars. We find that the strength of interaction between the wind and the stars depends on the ratio of wind velocity to orbital velocity (v∞/vorb) and on the binary mass ratio. Strong interaction occurs for close systems and comparable mass ratios, and gives rise to a complex morphology of the outflow and substantial angular-momentum loss, which leads to a shrinking of the orbit. As the orbital separation increases and the mass of the companion star decreases, the morphology of the outflow and the angular-momentum loss become more similar to the spherically symmetric wind case. We also explore the effects of tidal interaction and find that for orbital separations up to 7−10 AU, depending on mass ratio, spin-orbit coupling of the donor star occurs at some point during the AGB phase. If the initial wind velocity is relatively low, we find that corotation of the donor star results in a modified outflow morphology that resembles wind Roche-lobe overflow. In this case the mass-accretion efficiency and angular-momentum loss differ from those found for a non-rotating donor. Finally, we provide relations for the mass-accretion efficiency and angular-momentum loss as a function of v∞/vorb and the binary mass ratio that can be easily implemented in a population synthesis code to study populations of barium stars, CEMP stars, and other products of interaction in AGB binaries, such as cataclysmic binaries and type Ia supernovae.

scholarly journals A Global Analysis of The Generalized Sitnikov Problem

1999 ◽  
Vol 172 ◽  
pp. 291-302
Author(s):  
Steven R. Chesley
Keyword(s):  
Angular Momentum ◽  
Global Analysis ◽  
Mass Ratio ◽  
Three Body Problem ◽  
Bounded Motion ◽  
Type Symmetry ◽  
The Stability ◽  
Two Parameters ◽  
Three Body ◽  
Area Preserving

AbstractThe isosceles three-body problem with Sitnikov-type symmetry has been reduced to a two-dimensional area-preserving Poincaré map depending on two parameters: the mass ratio, and the total angular momentum. The entire parameter space is explored, contrasting new results with ones obtained previously in the planar (zero angular momentum) case. The region of allowable motion is divided into subregions according to a symbolic dynamics representation. This enables a geometric description of the system based on the intersection of the images of the subregions with the preimages. The paper also describes the regions of allowable motion and bounded motion, and discusses the stability of the dominant periodic orbit.

scholarly journals Close Binaries Before and After Mass Exchange: A Comparison of Observations through Theoretical Computations

1980 ◽  
Vol 88 ◽  
pp. 103-107
Author(s):  
J. P. De Grève ◽  
D. Vanbeveren
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Mass Exchange ◽  
Close Binaries ◽  
Mass Ratio ◽  
Momentum Loss ◽  
Averaged Equations ◽  
Angular Momentum Loss ◽  
Before And After ◽  
Large Angular Momentum

From a search through the literature 174 close binaries with completely known absolute dimensions are sampled. Distinction is made between systems before and after mass exchange, giving resp. 100 and 40 systems (a third group contains the systems not definitely belonging to these two). Mass, period and mass ratio distributions and relations of the group of “unevolved” binaries (i.e. prior to mass exchange) are transformed into corresponding distributions and relations of evolved binaries. The transformations are based upon the M1 f = g (M1 i) relation derived from an extended set of published theoretical computations on the evolution of close binaries. Final masses resulting from the same initial mass are averaged. Equations are derived for the cases A (for all masses), B1 (M1 i/Mo < 2.8), B2 (2.8 < M1 i/Mo < 9) and B3 (M1 i/Mo > 9). For the changes of the period due to angular momentum loss the formalism of Vanbeveren et al. (1979) was adopted. The following characteristics of the system after mass exchange are computed: M1 f, M2 f (and qf), Pf. Three different modes were applied for the mass loss from the system:a) conservative case (mass and angular momentum of the system remain constant), called C.b) non conservative case with 50% of the transferred mass leaving the system with a small or a large angular momentum loss (resp. called NC51 and NC53).c) non conservative case with 100% of the transferred mass leaving the system with a small or a large angular momentum loss (resp. called NC101 and NC103).

scholarly journals Accretion of Protobinary and Evolution of the Mass Ratio

2004 ◽  
Vol 191 ◽  
pp. 163-167
Author(s):  
Tomoyuki Hanawa ◽  
Yasuhiro Ochi ◽  
Kanako Sugimoto
Keyword(s):  
Angular Momentum ◽  
Surface Density ◽  
Accretion Rate ◽  
Orbital Plane ◽  
Gas Flows ◽  
Lagrangian Point ◽  
Mass Ratio ◽  
Fall Velocity ◽  
Rotation Periods ◽  
The Masses

AbstractWe have reexamined accretion in a protobinary system with two dimensional numerical simulations. We consider protostars which rotate around the center of the mass with circular orbits. The accreting gas is assumed to flow in the orbital plane. It is injected from a circle whose radius is 5 times larger than the orbital separation of the binary. The injected gas has constant surface density, in fall velocity, and specific angular momentum. The accretion depends on the specific angular momentum of the injected gas, jinf. When jinf is small, the binary accretes the gas mainly through two channels: one through the Lagrangian point L2 and the other through L3. When jinf is large, the binary accretes the gas only through the L2 point. The primary accretes more than the secondary in both cases, although the L2 point is closer to the secondary. After flowing through the L2 point, the gas flows half around the secondary and through the L1 point to the primary. Only a small amount of gas flows back to the secondary and the rest forms a circumstellar ring around the primary. The accretion decreases the mass ratio, q = M2/M1, where M1 and M2 denote the masses of the primary and secondary, respectively. The accretion rate increases with time. When jinf is large, it is negligibly small in the first few rotation periods.

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