The frequency of binaries with a degenerate component

1985 ◽  
Vol 110 (1) ◽  
pp. 149-152 ◽  
Author(s):  
J. L. Halbwachs
Keyword(s):  
Degenerate Component

scholarly journals Interacting binaries: an excellent project for small telescopes

1986 ◽  
Vol 118 ◽  
pp. 173-186
Author(s):  
Mirek J. Plavec
Keyword(s):  
Mass Transfer ◽  
Transfer Process ◽  
Stellar Evolution ◽  
Binary Systems ◽  
Mass Transfer Process ◽  
Circumstellar Matter ◽  
Light Curves ◽  
Evolutionary Stage ◽  
Degenerate Component ◽  
Interacting Systems

Discussed are meritorious projects for small and moderate telescopes in the field of interacting binaries with non-degenerate component stars. These interacting binaries are undergoing a mass transfer process, as a consequence of which the mass-accreting star may be partly or completely hidden in an accretion disk, and the system may be shrouded in dense clouds of circumstellar matter. This makes the observation, interpretation and modeling difficult; but it is important to study these “bizarre” binaries since they tell us a lot about stellar evolution in binary systems. Needed are various observations: Timing of eclipses; observation and re-observation of light curves in several colors (in uvby rather than in UBV; and in the red and infrared); radial velocity studies; spectrophotometry of crucial regions of the spectrum. As examples for these needs, the following systems are discussed in some detail, and their problems revealed: RX Cassiopeiae, W Serpentis, and W Crucis as examples of the strongly interacting systems (W Serpentids); U Sagittarii as a helium-rich binary in a rare evolutionary stage, which will be better understood if we decide whether the star eclipses or not; and KX Andromedae as a representative of non-eclipsing interacting binaries and of Be and shell stars, which may or may not be binaries.

scholarly journals White dwarf–main sequence star collisions from wide triples in the field

2021 ◽  
Vol 502 (3) ◽  
pp. 4540-4546
Author(s):  
Erez Michaely ◽  
Michael M Shara
Keyword(s):  
Main Sequence ◽  
Major Axis ◽  
Collision Rate ◽  
Semi Major Axis ◽  
Multiple Star ◽  
Compact Binary ◽  
Degenerate Component ◽  
Low Mass ◽  
Wave Emission ◽  
Merger Rate

ABSTRACT Multiple star systems interact strongly with galactic field stars when the outer semi-major axis of a triple or multiple star is >103 AU. Stable triples composed of two white-dwarfs (WD) and a low-mass main sequence (MS) star in a wide outer orbit can thus be destabilized by gravitational interactions with random field stars. Such interactions excite the eccentricity of the distant third star sufficiently so that it begins to interact significantly with the inner binary. When this occurs, the triple undergoes multiple binary-single resonant encounters. These encounters may result either in a collision between the non-degenerate component and a WD, or the breakup of the triple into a compact binary and a third object which is ejected. The compact binary can be either a MS–WD pair which survives, or collides or a double WD (DWD), which may inspiral through gravitational wave emission. We calculate the collision rate between a MS and WD star, and the merger rate of DWDs. Additionally, we describe the prospects of detectability of such a collision, which may resemble a sub-luminous supernovae event.

scholarly journals Evolution of a Degenerate Component in a Close Binary System

1979 ◽  
Vol 53 ◽  
pp. 48-51
Author(s):  
E.V. Ergma
Keyword(s):  
Binary System ◽  
Review Paper ◽  
Close Binary System ◽  
Close Binary ◽  
Hydrogen Burning ◽  
Degenerate Component

Investigation of evolution of a degenerate component (helium or carbon-oxygen dwarf) in a close binary system is rather important. Such dwarfs may be candidates for nova or supernova stars. The first possibility has been studied by several authors (see review paper by Starrfield et al., 1976) and it has been shown that explosive hydrogen burning with enriched CNO abundance in the degenerate envelope of a massive carbon-oxygen dwarf may explain nova phenomena.

scholarly journals Evolution of Globular Clusters Including a Degenerate Component

1988 ◽  
Vol 126 ◽  
pp. 665-666
Author(s):  
Hyung Mok Lee
Keyword(s):  
Globular Clusters ◽  
Main Sequence ◽  
High Mass ◽  
Main Sequence Stars ◽  
Compact Binaries ◽  
The Core ◽  
Degenerate Component ◽  
Low Mass ◽  
Mass Segregation ◽  
Very High

Low mass X-ray sources observed in many globular clusters are usually interpreted as compact binaries with degenerate components (e.g., Hertz and Grindlay 1983). Degenerate stars can exist in globular clusters if the IMF contains a sufficiently large number of high mass stars. Since the main-sequence lifetime is a very steep function of stellar mass, most of degenerate stars can be regarded as primordial. If the typical mass of degenerate stars is higher than that of main-sequence stars, mass segregation makes the core crowded with degenerate stars. Tidally captured binaries between degenerates and main-sequence stars can abundantly form as the core density becomes very high.

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