scholarly journals Inferred time-scales for common envelope ejection using wide astrometric companions

2020 ◽  
Vol 494 (1) ◽  
pp. 1448-1462 ◽  
Author(s):  
Andrei P Igoshev ◽  
Hagai B Perets ◽  
Erez Michaely
Keyword(s):  
Mass Loss ◽  
Time Scales ◽  
Cataclysmic Variables ◽  
Close Binaries ◽  
Ejection Time ◽  
Common Envelope ◽  
Use Of Data ◽  
The Common ◽  
F Stars ◽  
Gaia Dr2

ABSTRACT Evolution of close binaries often proceeds through the common envelope stage. The physics of the envelope ejection (CEE) is not yet understood, and several mechanisms were suggested to be involved. These could give rise to different time-scales for the CEE mass-loss. In order to probe the CEE-time-scales we study wide companions to post-CE binaries. Faster mass-loss time-scales give rise to higher disruption rates of wide binaries and result in larger average separations. We make use of data from Gaia DR2 to search for ultrawide companions (projected separations 103–2 × 105 au and M2 > 0.4 M⊙) to several types of post-CEE systems, including sdBs, white dwarf post-common binaries, and cataclysmic variables. We find a (wide-orbit) multiplicity fraction of 1.4 ± 0.2 per cent for sdBs to be compared with a multiplicity fraction of 5.0 ± 0.2 per cent for late-B/A/F stars which are possible sdB progenitors. The distribution of projected separations of ultrawide pairs to main sequence stars and sdBs differs significantly and is compatible with prompt mass-loss (upper limit on common envelope ejection time-scales of 102 yr). The smaller statistics of ultrawide companions to cataclysmic variables and post-CEE binaries provide weaker constraints. Nevertheless, the survival rate of ultrawide pairs to the cataclysmic variables suggest much longer, ∼104 yr time-scales for the CEE in these systems, possibly suggesting non-dynamical CEE in this regime.

scholarly journals IUE Observations of the Two Peculiar Binary Systems Beta Lyrae and Upsilon Sagittarii

1980 ◽  
Vol 88 ◽  
pp. 271-286 ◽  
Author(s):  
Margherita Hack ◽  
Umberto Flora ◽  
Paolo Santin
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Radial Velocity ◽  
Effective Temperature ◽  
Binary Systems ◽  
Close Binaries ◽  
Infrared Excess ◽  
Show Evidence ◽  
The Common ◽  
Ultraviolet Observations

The common peculiarities of these two systems are: a) the companion is a massive object (probably m2≥10) whose spectrum is not observable; b) both systems show evidence, though in different degrees, of mass-transfer and mass-loss; c) both present, in different degrees, hydrogen deficiency; d) ultraviolet observations have shown, in both cases, the presence of lines of highly ionized elements like N V, C IV, Si IV, probably formed in an extended envelope because they do not show orbital radial velocity shifts, and cannot be explained by the effective temperature of the star whose spectrum we observe. The latter property seems to be common to several close binaries, as shown by the ultraviolet observations with IUE by Plavec and Koch (1979); e) both systems present infrared excess, suggesting the presence of an extended envelope (Gehrz et al. 1974; Lee and Nariai, 1967; Humphreys and Ney, 1974; Treffers et al. 1976).

scholarly journals Evolution of binary stars with mass loss

1979 ◽  
Vol 83 ◽  
pp. 383-399
Author(s):  
Janusz Ziółkowski
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Binary Stars ◽  
Binary Systems ◽  
Close Binaries ◽  
Stellar Winds ◽  
Common Envelope ◽  
Weak Evidence ◽  
Orbital Periods ◽  
Detached Binaries

Three situations involving mass loss from binary systems are discussed. (1) Non-conservative mass exchange in semi-detached binaries. No quantitative estimate of this mechanism is possible at present. (2) Common envelope binaries. There are both theoretical and observational indications that this phase of evolution happens to many systems, even to some that are not very close initially (orbital periods ~ years). (3) Stellar winds in binaries. Observational evidence suggests that stellar winds from components of close binaries (especially semi-detached) are significantly stronger than from single stars at the same location in the H-R diagram. Theoretical arguments indicate that in some cases stellar wind may stabilize the component of a binary against the Roche lobe overflow. In some cases there is weak evidence of an anisotropy in the stellar wind.

scholarly journals Are white dwarf magnetic fields in close binaries generated during common-envelope evolution?

2019 ◽  
Vol 492 (1) ◽  
pp. 1523-1529 ◽  
Author(s):  
Diogo Belloni ◽  
Matthias R Schreiber
Keyword(s):  
Low Temperature ◽  
Magnetic Fields ◽  
Observational Data ◽  
White Dwarf ◽  
Close Binaries ◽  
Common Envelope ◽  
The Past ◽  
The Common ◽  
M Dwarf ◽  
Dynamo Process

ABSTRACT Understanding the origin of the magnetic fields in white dwarfs (WDs) has been a puzzle for decades. A scenario that has gained considerable attention in the past years assumes that such magnetic fields are generated through a dynamo process during common-envelope evolution. We performed binary population models using an up-to-date version of the bse code to confront the predictions of this model with observational results. We found that this hypothesis can explain only the observed distribution of WD magnetic fields in polars and pre-polars and the low-temperature WDs in pre-polars if it is re-scaled to fit the observational data. Furthermore, in its present version, the model fails to explain the absence of young, close detached WD+M-dwarf binaries harbouring hot magnetic WDs and predicts that the overwhelming majority of WDs in close binaries should be strongly magnetic, which is also in serious conflict with the observations. We conclude that either the common-envelope dynamo scenario needs to be substantially revised or a different mechanism is responsible for the generation of strong WD magnetic fields in close binaries.

Modelling the Common Envelope Phase in Classical Novae

1990 ◽  
Vol 122 ◽  
pp. 297-298
Author(s):  
Anurag Shankar ◽  
James W. Truran ◽  
Andreas Burkert ◽  
Mario Livio
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Orbital Plane ◽  
Orbital Energy ◽  
Classical Novae ◽  
Preliminary Results ◽  
Common Envelope ◽  
The Common

AbstractPreliminary results of 1– and 2– dimensional hydrodynamical calculations of the common envelope phase in very slow classical novae are presented. We show that frictional deposition of orbital energy and angular momentum into the envelope can potentially induce mass loss. Specifically, we find that despite rapid initial spin–up of the envelope, ejection of mass in the orbital plane continues at a substantial rate.

scholarly journals The Formation and Evolution of Compact Stars in Binaries

2004 ◽  
Vol 194 ◽  
pp. 81-84
Author(s):  
Ronald E. Taam
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Crucial Role ◽  
Binary Systems ◽  
Compact Objects ◽  
Compact Stars ◽  
Common Envelope ◽  
Formation And Evolution ◽  
The Common ◽  
Magnetic Braking

AbstractThe stellar evolutionary processes responsible for the formation of compact objects in interacting binary systems and their evolution are described. The common envelope phase plays a crucial role in their formation and angular momentum losses associated with magnetic braking and/or mass loss are important for their evolution. An application of these processes provides the evolutionary link between classes of interacting binary systems.

scholarly journals Gravitational waves from supernova mass loss and natal kicks in close binaries

2019 ◽  
Vol 490 (4) ◽  
pp. 5560-5566 ◽  
Author(s):  
A Miguel Holgado ◽  
Paul M Ricker
Keyword(s):  
Mass Loss ◽  
Gravitational Waves ◽  
Dynamical Evolution ◽  
Close Binaries ◽  
Orbital Energy ◽  
Core Collapse ◽  
Compact Binaries ◽  
Common Envelope ◽  
Binary Formation ◽  
Hubble Time

ABSTRACT Some fraction of compact binaries that merge within a Hubble time may have formed from two massive stars in isolation. For this isolated-binary formation channel, binaries need to survive two supernova (SN) explosions in addition to surviving common-envelope evolution. For the SN explosions, both the mass loss and natal kicks change the orbital characteristics, producing either a bound or unbound binary. We show that gravitational waves (GWs) may be produced not only from the core-collapse SN process, but also from the SN mass loss and SN natal kick during the pre-SN to post-SN binary transition. We model the dynamical evolution of a binary at the time of the second SN explosion with an equation of motion that accounts for the finite time-scales of the SN mass loss and the SN natal kick. From the dynamical evolution of the binary, we calculate the GW burst signals associated with the SN natal kicks. We find that such GW bursts may be of interest to future mid-band GW detectors like DECIGO. We also find that the energy radiated away from the GWs emitted due to the SN mass loss and natal kick may be a significant fraction, ${\gtrsim }10{\,{\rm {per\, cent}}}$, of the post-SN binary’s orbital energy. For unbound post-SN binaries, the energy radiated away in GWs tends to be higher than that of bound binaries.

scholarly journals The Later Evolution of the Contact Binaries AP Leo, AK Her, AB And and AM Leo

2002 ◽  
Vol 187 ◽  
pp. 331-336
Author(s):  
L. Li ◽  
Z. Han ◽  
F. Zhang
Keyword(s):  
Light Curve ◽  
Rapid Change ◽  
Cataclysmic Variables ◽  
Light Curves ◽  
Common Envelope ◽  
Physical Mechanisms ◽  
Contact Binaries ◽  
The Common ◽  
Long Term Variations

AbstractA detailed study of the periods and light curves of binaries AK Her, AP Leo, AB And and AM Leo is presented. Based on the study of the O – C curves, we find that the period variation of each system contains several components with different frequencies, and we suggest that the periodical variations in the periods are likely influenced by different mechanisms. Based on the study of the light curve changes, we find that the light curves exhibit two kinds of variations: rapid variations and long-term variations. We investigate the physical mechanisms which may underlie the variations of the period and the light curve of each system and obtain some new conclusions. According to the characteristics of the rapid light variation in these systems, we suggest that the rapid change in the light curve is probably caused by pulsation of the common envelope, and that the mechanism(s) causing the pulsation may be mass transfer through the inner Lagrangian point L1 or its variation. Finally, the evolutionary trends of these systems are discussed, and we suggest that these systems may be progenitors of cataclysmic variables.

scholarly journals ADIABATIC MASS LOSS AND THE OUTCOME OF THE COMMON ENVELOPE PHASE OF BINARY EVOLUTION

2010 ◽  
Vol 719 (1) ◽  
pp. L28-L31 ◽  
Author(s):  
Christopher J. Deloye ◽  
Ronald E. Taam
Keyword(s):  
Mass Loss ◽  
Common Envelope ◽  
The Common ◽  
Binary Evolution

Novae Between Outbursts

1990 ◽  
Vol 122 ◽  
pp. 342-350
Author(s):  
Mario Livio
Keyword(s):  
Present Status ◽  
Cataclysmic Variables ◽  
Orbital Plane ◽  
The Other ◽  
Common Envelope ◽  
Accretion Rates ◽  
The Common ◽  
Theoretical Evidence ◽  
Nova Outburst ◽  
Rapid Appearance

AbstractThe paper is divided into two parts. In the first part, the common envelope phase that follows a nova outburst is discussed. It is shown that this phase leads to mass loss, preferentially in the orbital plane. It is argued, that the common envelope can explain the rapid appearance of a nebular spectrum in novae and the shaping of the nebula.In the second part, the present status of the cyclic-evolution (“hibernation”) scenario is reviewed. It is argued that novae and dwarf novae are the same systems, transforming from one class to the other. Observational and theoretical evidence is presented, that shows that both the accretion rates and the white dwarf masses in observed nova systems should be higher than the average. Novae should therefore not be regarded as “typical” cataclysmic variables. Some critical observations that can provide observational tests are suggested.

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