scholarly journals Wind Driven Mass Transfer in Interacting Binaries

1992 ◽  
Vol 151 ◽  
pp. 363-366
Author(s):  
Christopher A. Tout ◽  
Douglas S. Hall
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Binary Systems ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Mass Transfer Rate ◽  
Close Binary ◽  
Driving Mechanism ◽  
Simple Explanation ◽  
Quantitative Estimates

Stars in close binary systems can suffer two kinds of mass change: 1) mass transfer between the stars 2) mass loss completely from the system. Observational estimates indicate that these are of the same order. A simple explanation can be found if the mass loss, by stellar wind, from the Roche-filling star is the driving mechanism behind mass transfer. We find quantitative estimates for the necessary conditions and find that the mass transfer rate and the mass loss rate are indeed similar. We find that the radii of evolved semi-detached systems are more consistent with wind-driven evolution than the traditional nuclear-driven Roche-lobe overflow.

scholarly journals Unsteady Mass Loss in Close Binaries

1976 ◽  
Vol 73 ◽  
pp. 329-329
Author(s):  
R. F. Webbink
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Thermal Instability ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Mass Transfer Rate ◽  
Close Binaries ◽  
Convective Envelope ◽  
Initial Separation ◽  
Hydrostatic Treatment

The evolution of a system of 1.50M⊙ and 0.50M⊙ components with initial separation 3.00R⊙ is presented. The primary reaches its Roche lobe after 6.108 × 108 yr, and the mass loss rate grows quickly to ~ 1.1 × 10−7M⊙ yr−1. The deep convective envelope of the secondary contracts in response to accretion, however, and the system avoids contact, even though the main sequence mass-radius relationship crosses the Roche relationship at 0.758M⊙.The growth of the convective envelope of the primary with mass loss prevents thermaltimescale mass transfer from reaching any stable value. The mass loss rate continues to increase as a result of the tendency of the growing convective envelope to expand with mass loss. A Bath-type pulsational instability in the mass transfer rate is manifested as a longer-period thermal instability in the hydrostatic treatment. Eventually mass loss proceeds on a dynamical timescale, reaching 1.5 × 10−4M⊙yr−1. This is followed by a detached phase with the mass ratio not yet reversed, and a second dynamical episode leaving a 0.6666M⊙ + 1.3334M⊙ binary still in a semi-detached state. The original secondary, now more massive, has a surface luminosity of 0.0538L⊙ but a nuclear luminosity of 1540L⊙, and a convective core of 1.076M⊙ separated by a radiative zone of only 0.028M⊙ from its convective envelope.An attempt is made to follow the evolution of the secondary in the case where the stream energy, much greater than the intrinsic luminosity of the secondary, is dissipated spherically symmetrically at its surface. The outer envelope departs radically from the previous case, an optically deep radiative surface layer forming, and the convection zone splitting into two, the lower one remaining very massive. Because the mass transfer timescale is short compared with the thermal timescale of the secondary, however, it is concluded that the stream luminosity cannot significantly alter the evolution of the secondary.

scholarly journals Mass Loss and Shell Masses of Close Binary Stars

1987 ◽  
Vol 93 ◽  
pp. 675-679
Author(s):  
V.G. Karetnikov
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Binary Stars ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Close Binary ◽  
Time Interval ◽  
Close Binary Stars

AbstractFrom the values of period changes for 6 close binary stars the mass transfer rate was calculated. Comparing these values Mt with the values of shell masses Msh, the expressionwas derived. The analysis of this expression points out the initial character of the outflow of matter, and one may determine the time interval of the substitution of the shell matter. So one may conclude that for a certain mass transfer rate, a certain amount of matter accumulates in the nearby regions of the system.

scholarly journals Features of the kinetics of mass transfer processes in the process of firing ceramic materials

2018 ◽  
pp. 29-31
Author(s):  
O.M. Nedbailo ◽  
O.G. Chernyshyn
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Ceramic Materials ◽  
The Body ◽  
Mass Content ◽  
Transfer Coefficients ◽  
Average Mass ◽  
Firing Ceramic

In article the technique of definition factors of carrying over weight of substance in the course of roasting ceramic materials which is based on exponent dependences of change mass bodies from time of its heating is offered. The process of firing ceramic materials is associated with the transfer of heat and mass of matter. Therefore, for a more complete calculation of the heat treatment mode, it is necessary to know the conditions for the mass transfer in the product being calcined. The aim of the work is to determine the mass transfer coefficients of the substance in the process of firing ceramic materials. The mass loss rate of the bound matter or the mass loss per unit time will be directly proportional to the average mass content of the body. On the other hand, the mass loss rate of the bound matter is numerically equal to the slope of the mass content kinetics curve. Proposed in the work formulas can be applied when studying the process of mass transfer during firing of samples from different clays, as when firing clay samples of different diameters under the same conditions, they will differ in the mass content (mass loss rate of the bound substance) during heating and their final relative amount (mass content) of the lost mass will be the same.

scholarly journals A Gentle Process for the Formation of Algols

1989 ◽  
Vol 107 ◽  
pp. 369-369
Author(s):  
C. A. Tout ◽  
P. P. Eggleton
Keyword(s):  
Mass Transfer ◽  
Magnetic Fields ◽  
Mass Loss ◽  
White Dwarf ◽  
Binary Systems ◽  
Roche Lobe ◽  
Close Binary ◽  
Red Giants ◽  
Convective Envelope ◽  
Mass Ratios

AbstractThis work is concerned with binary systems that we call ‘moderately close’. These are systems in which the primary (by which we mean the initially more massive star) fills its Roche lobe when it is on the giant branch with a deep convective envelope but before helium ignition (late case B). We find that if the mass ratio q(= M1/M2) < qCrit = 0.7 when the primary fills its Roche lobe positive feedback will lead to a rapid hydrodynamic phase of mass transfer which will probably lead to common envelope evolution and thence to either coalescence or possibly to a close binary in a planetary nebula. Although most Algols have probably filled their Roche lobes before evolving off the main-sequence we find that some could not have and are therefore ‘moderately close’. Since rapid overflow is unlikely to lead to an Algol-like system there must be some way of avoiding it. The most likely possibility is that the primary can lose sufficient mass to reduce q below qcrit before overflow begins. Ordinary mass loss rates are insufficient but evidence that enhanced mass loss does take place is provided by RS CVn systems that have inverted mass ratios but have not yet begun mass transfer. We postulate that the cause of enhanced mass loss lies in the heating of the corona by by magnetic fields maintained by an α-ω dynamo which is enhanced by tidal effects associated with corotation. In order to model the the effects of enhanced mass loss we ignore the details and adopt an empirical approach calibrating a simple formula with the RS CVn system Z Her. Using further empirical relations (deduced from detailed stellar models) that describe the evolution of red giants we have investigated the effect on a large number of systems of various initial mass ratios and periods. These are notable in that some systems can now enter a much gentler Algol-like overflow phase and others are prevented from transferring mass altogether. We have also investigated the effects of enhanced angular momentum loss induced by corotation of the wind in the strong magnetic fields and consider this in relation to observed period changes. We find that a typical ‘moderately close’ Algol-like system evolves through an RS CVn like system and then possibly a symbiotic state before becoming an Algol and then goes on through a red giant-white dwarf state which may become symbiotic before ending up as a double white dwarf system in either a close or wide orbit depending on how much mass is lost before the secondary fills its Roche lobe.

scholarly journals The Evolution of Massive Close Binary Systems : Estimates of the Parameters Governing Mass and Angular Momentum Loss

1980 ◽  
Vol 88 ◽  
pp. 115-121
Author(s):  
D. Vanbeveren ◽  
C. De Loore
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Binary Systems ◽  
Mass Loss Rate ◽  
Roche Lobe ◽  
Close Binary ◽  
Close Binaries ◽  
Stellar Winds ◽  
Binary Evolution ◽  
Image Position

It becomes more and more evident that for close binary evolution during Roche lobe overflow as well mass transfer as mass loss occurs. When a mass element ΔM is expelled from the primary during this phase, a fraction β is transferred to the secondary; the remaining part leaves the system. Moreover, angular momentum leaves the system, and also this fraction has to be specified; this fraction is related to a parameter α (Vanbeveren et al., 1979). For the computation of the evolution of massive close binaries also mass loss due to stellar wind of both components, prior to the Roche lobe overflow has to be taken into account. The mass loss rate Ṁ due to radiation driven stellar winds can be expressed as

scholarly journals Mass loss from interacting close binary systems

1981 ◽  
Vol 59 ◽  
pp. 431-456
Author(s):  
Mirek J. Plavec
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Binary Stars ◽  
Binary Systems ◽  
Close Binary ◽  
Important Process ◽  
Close Binary Systems ◽  
Complex Process ◽  
General Complex ◽  
Mass Outflow

AbstractMass outflow from interacting close binary systems, accompanied by loss of orbital angular momentum, appears to be a very important process affecting the evolution of binary stars. Together with accretion on the mass-gaining component, it is the least understood aspect of the general complex process we call “evolution with mass transfer and/or mass loss”, or, more briefly, “interaction”. It is therefore very imperative to assemble and examine all available facts or hints about mass loss.

scholarly journals Evolution of Intermediate Mass Close Binaries

1980 ◽  
Vol 88 ◽  
pp. 109-114
Author(s):  
Th.J. Van Der Linden
Keyword(s):  
Mass Transfer ◽  
Binary Systems ◽  
Main Sequence ◽  
Mass Transfer Rate ◽  
Primary Component ◽  
Close Binary ◽  
Close Binaries ◽  
Transfer Phase ◽  
Helium Burning ◽  
Helium Star

Numerical simulations of close binary evolution were performed for five binary systems, using a newly developed evolutionary program. The systems have masses 3+2, 4+3.2, 6+4, 9+6, 12+8 M⊙ and periods 2d, 1d78, 3d, 4d, 5d respectively. The primary component was followed from the zero-age main sequence through the mass transfer phase to core-helium burning. Special care was given to the self-consistent determination of the mass transfer rate and the detailed treatment of composition changes. After the mass transfer phase the resulting systems consist of a main sequence star with a helium star companion of mass 0.36, 0.46, 0.82, 1.48, 2.30 M⊙ for the five systems respectively. Interesting “thermal pulses” were found in the 3+2 M⊙ system at the onset of helium burning.

scholarly journals The Formation of White Dwarfs in Close Binary Systems

1979 ◽  
Vol 53 ◽  
pp. 426-447 ◽  
Author(s):  
Ronald F. Webbink
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
White Dwarfs ◽  
Binary Systems ◽  
Physical Contact ◽  
Close Binary ◽  
Second Phase ◽  
Short Period ◽  
Qualitative Evolution ◽  
Modes Of Interaction

AbstractThree major modes of interaction in binary systems are identified, corresponding to (I) physical contact, (II) tidal mass loss from a star with a radiative envelope, and (III) tidal mass loss from a star with a convectlve envelope. The qualitative evolution of binary systems in each of these cases is outlined, leading to the formation of single white dwarfs, long-period remnants of quasi-conservative mass transfer, or short-period cataclysmic binaries. The origin of short-period double white dwarfs in a second phase of mass transfer is outlined. Implications for the frequency of different systems of these types, and of planetary nebulae with close binary nuclei, are discussed.

scholarly journals Observations of Circumstellar Clouds

1980 ◽  
Vol 87 ◽  
pp. 487-493
Author(s):  
P. G. Wannier ◽  
R. O. Redman ◽  
T. G. Phillips ◽  
R. B. Leighton ◽  
G. R. Knapp ◽  
...  
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Large Mass ◽  
Close Binary ◽  
Excitation Temperature ◽  
Orbital Velocity ◽  
Carbon Stars ◽  
Co Emission

Observations have been made of J=2-1 CO in eleven circumstellar clouds including seven carbon stars and four oxygen-rich stars. Observations in four sources, including IRC+10216 have already been published (Wannier et al. 1979, henceforth Paper I) and the remaining observations are being prepared for publication (Knapp et al. 1980, henceforth Paper II). Several results are discussed below with special emphasis on the implications for two sources, namely IRC+10216 and Mira (o Ceti). The observations of IRC+10216 show CO emission over a diameter of 6 arcmin (∼ 0.5pc), a result suggesting a very large mass-loss rate. Mira is unique among the objects studied in displaying a small CO opacity and a high CO excitation temperature. It is suggested that this heating results from the orbital velocity of Mira due to its close binary companion.

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