Evolution of rotationally and tidally distorted low-mass, close binary systems - Implications for the minimum orbital period of cataclysmic variables

1985 ◽  
Vol 299 ◽  
pp. 658 ◽  
Author(s):  
L. A. Nelson ◽  
W. Y. Chau ◽  
A. Rosenblum
Keyword(s):  
Orbital Period ◽  
Binary Systems ◽  
Cataclysmic Variables ◽  
Close Binary ◽  
Close Binary Systems ◽  
Low Mass

scholarly journals Superoutbursts and Superhumps of SU UMa Stars

1988 ◽  
Vol 108 ◽  
pp. 238-239
Author(s):  
Yoji Osaki ◽  
Masahito Hirose
Keyword(s):  
Accretion Disk ◽  
Orbital Period ◽  
White Dwarf ◽  
Binary Systems ◽  
Roche Lobe ◽  
Light Curves ◽  
Close Binary ◽  
Dwarf Novae ◽  
Dwarf Nova ◽  
Close Binary Systems

SU UMa stars are one of subclasses of dwarf novae. Dwarf novae are semi-detached close binary systems in which a Roche-lobe filling red dwarf secondary loses matter and the white dwarf primary accretes it through the accretion disk. The main characteristics of SU UMa subclass is that they show two kinds of outbursts: normal outbursts and superoutbursts. In addition to the more frequent narrow outbursts of normal dwarf nova, SU UMa stars exhibit “superoutbursts”, in which stars reach about 1 magnitude brighter and stay longer than in normal outburst. Careful photometric studies during superoutburst have almost always revealed the “superhumps”: periodic humps in light curves with a period very close to the orbital period of the system. However, the most curious of all is that this superhump period is not exactly equal to the orbital period, but it is always longer by a few percent than the orbital period.

scholarly journals Numerical Calculations for Accretion Disks in Close Binary Systems

1982 ◽  
Vol 69 ◽  
pp. 219-230 ◽  
Author(s):  
G. Hensler
Keyword(s):  
Accretion Disks ◽  
Binary Systems ◽  
Hot Spot ◽  
Cataclysmic Variables ◽  
Close Binary ◽  
Special Treatment ◽  
Theoretical Understanding ◽  
Close Binary Systems ◽  
M 10 ◽  
Good Spatial Resolution

AbstractA numerical method for 3D magnetohydrodynamical investigations of accretion disks in close binary systems is presented, which allows for good spatial resolution of structures (hot spot, accretion column). The gas is treated as individual gas cells (pseudo-particles) whose motion is calculated within a grid consisting of one spherical inner part for 3D MHD and two plane outer parts. Viscous interactions of the gas cells are taken into account by a special treatment connected with the grid geometry.We present one result of 2D hydrodynamical calculations for a binary applying the following parameters which are representative for Cataclysmic Variables: M1 = 1 Mʘ, r1 = 10-2 Rʘ, M2 = 0.5 Mʘ, p = 0.2 d, M = 10-9 Mʘ y-1.Column density and radiative flux distributions over the disk are shown and briefly discussed by comparison with the theoretical understanding of these Dwarf Novae drawn from observations.

scholarly journals Internal magnetic fields, spin-orbit coupling, and orbital period modulation in close binary systems

2019 ◽  
Author(s):  
A F Lanza
Keyword(s):  
Orbital Period ◽  
Binary Systems ◽  
Orbit Coupling ◽  
Close Binary ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Active Components ◽  
Momentum Exchange ◽  
Hot Jupiters ◽  
Close Binary Systems

Abstract We introduce a new model to explain the modulation of the orbital period observed in close stellar binary systems based on an angular momentum exchange between the spin of the active component and the orbital motion. This spin-orbit coupling is not due to tides, but is produced by a non-axisymmetric component of the gravitational quadrupole moment of the active star due to a persistent non-axisymmetric internal magnetic field. The proposed mechanism easily satisfies all the energy constraints having an energy budget ∼102 − 103 times smaller than those of previously proposed models and is supported by the observations of persistent active longitudes in the active components of close binary systems. We present preliminary applications to three well-studied binary systems to illustrate the model. The case of stars with hot Jupiters is also discussed showing that no significant orbital period modulation is generally expected on the basis of the proposed model.

scholarly journals Evolution Into Contact of the Low-Mass Close Binary Systems

1989 ◽  
Vol 107 ◽  
pp. 361-361
Author(s):  
M.J. Sarna ◽  
A.V. Fedorova
Keyword(s):  
Binary Systems ◽  
Close Binary ◽  
Close Binary Systems ◽  
Low Mass

AbstractWe investigated the effect of mass accretion on the secondary components in close binomy systems (Mtotal ≤ 2.5M⊙M2.0 ≤ 0.75M⊙) exchanging mass in the case A.

Evolution of low-mass close binary systems

1988 ◽  
Vol 328 ◽  
pp. 617 ◽  
Author(s):  
P. N. McDermott ◽  
Ronald E. Taam ◽  
F. A. Ringwald
Keyword(s):  
Binary Systems ◽  
Close Binary ◽  
Close Binary Systems ◽  
Low Mass
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