scholarly journals The evolutionary status of symbiotic stars

1982 ◽  
Vol 70 ◽  
pp. 275-282 ◽  
Author(s):  
Bronislaw Rudak
Keyword(s):  
Cataclysmic Variables ◽  
Evolutionary Status ◽  
Spherically Symmetric ◽  
Symbiotic Stars ◽  
Transfer Phase ◽  
Common Envelope ◽  
Long Period ◽  
Red Giant ◽  
Detached Binaries ◽  
Rapid Mass

AbstractThe evolutionary relations between symbiotic stars and cataclysmic variables are presented. The symbiotic stars are assumed to be long period detached binaries containing a carbon-oxygen degenerate primary and a red giant losing its mass through a spherically symmetric wind. Such systems can be obtained in Case C evolution, provided a common envelope during a rapid mass transfer phase was not formed. The same way recurrent novae containing a red giant as a secondary component may be produced. The factors influencing the differences between symbiotic stars and nova-type stars are discussed.

scholarly journals Symbiotic Binary Stars

1992 ◽  
Vol 151 ◽  
pp. 137-146
Author(s):  
Scott J. Kenyon
Keyword(s):  
White Dwarf ◽  
Binary Stars ◽  
Main Sequence ◽  
Cataclysmic Variables ◽  
Symbiotic Stars ◽  
Paper Briefly ◽  
Primary Star ◽  
Classical Novae ◽  
Long Period ◽  
Red Giant

This paper briefly reviews the physical properties of symbiotic stars: long-period interacting binaries composed of a red giant primary star and a hot companion. Two types of binaries produce symbiotic optical spectra: semi-detached systems with a main sequence secondary and detached systems with a white dwarf secondary. Semi-detached symbiotics resemble cataclysmic variables and Algol binaries, but on a much larger scale, and undergo dwarf nova-like eruptions. Wind accretion powers detached systems; occasional thermonuclear runaways produce symbiotic novae - distant cousins of classical novae.

scholarly journals From Common Envelope to Pre-Cataclysmic Variables: An Observational Test of Common Envelope Evolution

1996 ◽  
Vol 158 ◽  
pp. 453-456
Author(s):  
M. J. Sarna
Keyword(s):  
Gravitational Radiation ◽  
Planetary Nebula ◽  
Cataclysmic Variables ◽  
Orbital Energy ◽  
Dwarf Star ◽  
Common Envelope ◽  
Evolutionary Scenario ◽  
Angular Momentum Loss ◽  
Red Giant ◽  
Detached Binaries

The generally accepted evolutionary scenario for cataclysmic variables (CVs) is common envelope (CE) evolution (Iben & Livio 1993) proposed by Paczyñski (1976). The secondary spirals towards the giant’s compact core converting orbital energy into kinetic energy of the giant’s envelope and the envelope is ejected. The dynamics of the red dwarf and red giant envelope interaction have been studied by several groups (Livio & Soker 1988; Taam & Bodenheimer 1991). After the ejection of the red giant envelope the post common envelope detached binaries (PCEBs) are formed. These can be divided into three groups:• Hot subdwarf with a red dwarf star inside a planetary nebula.• Hot subdwarf with a red dwarf star without a planetary nebula.• Hot white dwarf with a red dwarf star without a planetary nebula. Next, due to angular momentum loss by magnetic braking and/or gravitational radiation, the red dwarf component fills its Roche lobe and a cataclysmic variable is formed.

scholarly journals Problems in Common Envelope Evolution as a Pre-Stage of Cataclysmic Variables

1979 ◽  
Vol 53 ◽  
pp. 520-520
Author(s):  
F. Meyer ◽  
E. Meyer-Hofmeister
Keyword(s):  
Angular Momentum ◽  
Thermal Instability ◽  
Main Sequence ◽  
Cataclysmic Variables ◽  
Main Sequence Star ◽  
Common Envelope ◽  
Angular Momentum Transport ◽  
Binary Separation ◽  
Low Mass ◽  
Red Giant

We follow the evolution of an originally widely separated red-giant in orbit with a low mass main sequence star to a cataclysmic binary system. Angular momentum transport via differential rotation leads to a common envelope around the red giant core and the main sequence star. The internal binary separation shrinks by frictional transfer of angular momentum to the extended red giant envelope. This shrinkage continues at nearly constant luminosity until after several hundred years the binary “Roche lobe” cuts into the dense layers of the main sequence star. The envelope will then be lost by a thermal instability. Method and computations for a 5 M⊙ + 1 M⊙ binary are presented elsewhere (Astron. Astrophys. 1979, in press).

scholarly journals Optical and Near-IR Monitoring of Symbiotic Binary Systems

2001 ◽  
Vol 183 ◽  
pp. 167-176
Author(s):  
Joanna Mikołajewska
Keyword(s):  
Binary Systems ◽  
Variable Stars ◽  
Type Star ◽  
Symbiotic Stars ◽  
Future Prospects ◽  
Dust Shell ◽  
Giant Star ◽  
Long Period ◽  
Near Ir ◽  
Red Giant

AbstractSymbiotic stars are long-period interacting binary systems in which an evolved red giant star transfers material to its much hotter compact companion. Such a composition places them among the most variable stars. In addition to periodic variations due to the binary motion, they often show irregular changes due to nova-like eruptions of the hot component. In some systems the cool giant is a pulsating Mira-type star usually surrounded by a variable dust shell. Here, I present results of optical and IR monitoring of symbiotic systems as well as future prospects for such studies.

scholarly journals HD 101584: circumstellar characteristics and evolutionary status

2019 ◽  
Vol 623 ◽  
pp. A153 ◽  
Author(s):  
H. Olofsson ◽  
T. Khouri ◽  
M. Maercker ◽  
P. Bergman ◽  
L. Doan ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
Good Evidence ◽  
Spectral Energy ◽  
Evolutionary Status ◽  
Compact Source ◽  
Common Envelope ◽  
Density Enhancement ◽  
Circumstellar Gas ◽  
Red Giant ◽  
Binary Object

Context. There is growing evidence that red giant evolution is often affected by an interplay with a nearby companion, in some cases taking the form of a common-envelope evolution. Aims. We have performed a study of the characteristics of the circumstellar environment of the binary object HD 101584, that provides information on a likely evolutionary scenario. Methods. We have obtained and analysed ALMA observations, complemented with observations using APEX, of a large number of molecular lines. An analysis of the spectral energy distribution has also been performed. Results. Emissions from 12 molecular species (not counting isotopologues) have been observed, and most of them mapped with angular resolutions in the range 0.′′1–0.′′6. Four circumstellar components are identified: (i) a central compact source of size ≈0.′′15, (ii) an expanding equatorial density enhancement (a flattened density distribution in the plane of the orbit) of size ≈3′′, (iii) a bipolar high-velocity outflow (≈150 km s−1), and (iv) an hourglass structure. The outflow is directed almost along the line of sight. There is evidence of a second bipolar outflow. The mass of the circumstellar gas is ≈0.5 [D/1 kpc]2 M⊙, about half of it lies in the equatorial density enhancement. The dust mass is ≈0.01 [D/1 kpc]2 M⊙, and a substantial fraction of this is in the form of large-sized, up to 1 mm, grains. The estimated kinetic age of the outflow is ≈770 [D/1 kpc] yr. The kinetic energy and the scalar momentum of the accelerated gas are estimated to be 7 × 1045 [D/1 kpc]2 erg and 1039 [D/1 kpc]2 g cm s−1, respectively. Conclusions. We provide good evidence that the binary system HD 101584 is in a post-common-envelope-evolution phase, that ended before a stellar merger. Isotope ratios combined with stellar mass estimates suggest that the primary star’s evolution was terminated already on the first red giant branch (RGB). Most of the energy required to drive the outflowing gas was probably released when material fell towards the companion.

scholarly journals Long-Period Variables and Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 386-389
Author(s):  
Donald H. Menzel
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Planetary Nebulae ◽  
Symbiotic Stars ◽  
Long Period ◽  
Long Period Variables ◽  
Stellar Photosphere ◽  
Period Variable ◽  
Red Giant ◽  
The Magnetic Field

The occasional appearance of a red giant or long-period variable in planetary nebulae poses a problem for theoretical astrophysics. Such a cool nuclear star would not ordinarily provide a source of ultraviolet radiation necessary for the excitation of the spectrum of a gaseous nebula.One possible solution of this problem postulates the existence of intense magnetic fields in the star. Second, the star itself has a structure resembling that of a miniature, highly compressed planetary, with a high-temperature nuclear star at the centre and a distended atmospheric shell enveloping chiefly the stellar equator.The magnetic field induces a sort of pumping action that creates the tire-shaped envelope from matter ejected near the poles. As this shell grows denser, it radiates like a stellar photosphere at low temperature. Eventually the shell becomes unstable and disperses outward to form and maintain the nebula. A quasi-periodic situation occurs, which explains the variation of light. Ultraviolet light absorbed during the minima, when the shell has vanished, adequately accounts for the nebular excitation. A wide variety of such symbiotic stars occurs, including repeating novae as well as the long-period variables.

BM Cas – a long-period eclipsing young supergiant binary system in common envelope stage

2007 ◽  
Vol 26 (4-5) ◽  
pp. 339-350 ◽  
Author(s):  
I. Pustylnik ◽  
P. Kalv ◽  
V. Harvig ◽  
T. Aas
Keyword(s):  
Binary System ◽  
Common Envelope ◽  
Long Period ◽  
Cas A

scholarly journals HS 0139+0559, HS 0229+8016, HS 0506+7725, and HS 0642+5049: four new long-period cataclysmic variables

2005 ◽  
Vol 443 (3) ◽  
pp. 995-1005 ◽  
Author(s):  
A. Aungwerojwit ◽  
B. T. Gänsicke ◽  
P. Rodríguez-Gil ◽  
H.-J. Hagen ◽  
E. T. Harlaftis ◽  
...  
Keyword(s):  
Cataclysmic Variables ◽  
Long Period

scholarly journals Energy Transfer by Circulation in W Ursae Majoris Systems

1980 ◽  
Vol 88 ◽  
pp. 495-499
Author(s):  
David H. Smith ◽  
Robert Connon Smith ◽  
J. Alistair Robertson
Keyword(s):  
Large Scale ◽  
Vertical Motion ◽  
Spherically Symmetric ◽  
Convective Envelope ◽  
Common Envelope ◽  
Binary Model ◽  
Contact Binaries ◽  
Contact Binary ◽  
Horizontal Pressure ◽  
The Common

After Lucy (1968) introduced the contact-binary model with a common convective envelope, it was envisaged by Hazlehurst & Meyer-Hofmeister (1973) that a sideways flow of convective elements would carry energy from the more luminous star, the primary, to the less luminous star, the secondary, as a result of horizontal pressure variations. Webbink (1977) extended this picture by noting that the interaction between vertical entropy gradients and large-scale smooth circulation currents in the common envelope would provide the necessary redistribution of flux. That is, energy is absorbed by the flow during its vertical motion in the primary and is released during its vertical motion in the secondary. Webbink (1977) mentioned two mechanisms by which a large-scale circulation could be generated: (1) the non-spherically symmetric force field due to rotation and tides which will drive an analogue of classical Eddington-Sweet circulation and (2) differential heating of the base of the common envelope. Although these mechanisms are conceptually different, they are not in practice easy to disentangle, and will certainly both be operating in contact binaries.

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