scholarly journals Interacting young M-dwarfs in triple system – Par 1802 binary system case study

2019 ◽  
Vol 489 (2) ◽  
pp. 2298-2306 ◽  
Author(s):  
Shelley J Cheng ◽  
Alec M Vinson ◽  
Smadar Naoz
Keyword(s):  
Mass Transfer ◽  
Binary Systems ◽  
Main Sequence ◽  
Binary Star ◽  
Dynamical Evolution ◽  
Sequence Evolution ◽  
Proof Of Concept ◽  
Orion Nebula ◽  
Roche Limit ◽  
Tidal Heating

ABSTRACT The binary star Par 1802 in the Orion Nebula presents an interesting puzzle in the field of stellar dynamics and evolution. Binary systems such as Par 1802 are thought to form from the same natal material and thus the stellar members are expected to have very similar physical attributes. However, Par 1802’s stars have significantly different temperatures despite their identical (within $3\, {\rm per\, cent}$) masses of about 0.39 M⊙. The leading proof-of-concept idea is that a third companion gravitationally induced the two stars to orbit closer than their Roche limit, which facilitated heating through tidal effects. Here we expand on this idea and study the three-body dynamical evolution of such a system, including tidal and pre-main-sequence evolution. We also include tidal heating and mass transfer at the onset of Roche limit crossing. We show, as a proof-of-concept, that mass transfer combined with tidal heating can naturally explain the observed temperature discrepancy. We also predict the orbital configuration of the possible tertiary companion. Finally, we suggest that the dynamical evolution of such a system has pervasive consequences. We expect an abundance of systems to undergo mass transfer during their pre-main-sequence time, which can cause temperature differences.

scholarly journals Massive donors in interacting binaries: effect of metallicity

2020 ◽  
Vol 638 ◽  
pp. A55 ◽  
Author(s):  
Jakub Klencki ◽  
Gijs Nelemans ◽  
Alina G. Istrate ◽  
Onno Pols
Keyword(s):  
Mass Transfer ◽  
Parameter Space ◽  
Binary Systems ◽  
Main Sequence ◽  
Massive Stars ◽  
First Episode ◽  
Sequence Evolution ◽  
Radial Expansion ◽  
Solar Metallicity ◽  
Order Of Magnitude

Metallicity is known to significantly affect the radial expansion of a massive star: the lower the metallicity, the more compact the star, especially during its post-main sequence evolution. Our goal is to study this effect in the context of binary evolution. Using the stellar-evolution code MESA, we computed evolutionary tracks of massive stars at six different metallicities between 1.0 Z⊙ and 0.01 Z⊙. We explored variations of factors known to affect the radial expansion of massive stars (e.g., semiconvection, overshooting, or rotation). Using observational constraints, we find support for an evolution in which already at a metallicity Z ≈ 0.2 Z⊙ massive stars remain relatively compact (∼100 R⊙) during the Hertzprung-gap (HG) phase and most of their expansion occurs during core-helium burning (CHeB). Consequently, we show that metallicity has a strong influence on the type of mass transfer evolution in binary systems. At solar metallicity, a case-B mass transfer is initiated shortly after the end of the main sequence, and a giant donor is almost always a rapidly expanding HG star. However, at lower metallicity, the parameter space for mass transfer from a more evolved, slowly expanding CHeB star increases dramatically. This means that envelope stripping and formation of helium stars in low-metallicity environments occurs later in the evolution of the donor, implying a shorter duration of the Wolf-Rayet phase (even by an order of magnitude) and higher final core masses. This metallicity effect is independent of the effect of metallicity-dependent stellar winds. At metallicities Z ≤ 0.04 Z⊙, a significant fraction of massive stars in binaries with periods longer than 100 days engages in the first episode of mass transfer very late into their evolution, when they already have a well-developed CO core. The remaining lifetime (≲104 yr) is unlikely to be long enough to strip the entire H-rich envelope. Cases of unstable mass transfer leading to a merger would produce CO cores that spin fast at the moment of collapse. We find that the parameter space for mass transfer from massive donors (> 40 M⊙) with outer convective envelopes is extremely small or even nonexistent. We briefly discuss this finding in the context of the formation of binary black hole mergers.

scholarly journals Binary Stars in Young Clusters –a Theoretical Perspective

2001 ◽  
Vol 200 ◽  
pp. 199-209 ◽  
Author(s):  
Pavel Kroupa
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Main Sequence ◽  
Binary Star ◽  
Theoretical Perspective ◽  
Sequence Evolution ◽  
Orbital Elements ◽  
Stellar Interiors ◽  
Cluster Cores ◽  
Initial Distributions

The preponderance of binary systems in all known stellar populations makes them exciting dynamical agents for research on topics as varied as star formation, star-cluster dynamics and the interiors of young and old stars. Today we know that the Galactic-field binary population is probably a dynamically evolved version of the Taurus–Auriga pre-main sequence population, and that the initial distributions of binary-star orbital elements are probably universal. Furthermore, N-body calculations tentatively suggest that OB stars form in energetic binaries near cluster cores, and that binaries with ‘forbidden’ orbital elements that are produced in stellar encounters, may turn out to be very useful windows into stellar interiors, potentially allowing tests of pre-main sequence evolution theory as well as of models of main-sequence stars.

scholarly journals Asteroseismology of Close Binary Stars: Tides and Mass Transfer

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhao Guo
Keyword(s):  
Mass Transfer ◽  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Close Binary ◽  
Close Binaries ◽  
Linear Mode ◽  
Stellar Oscillations ◽  
Theoretical Approaches ◽  
Stellar Interiors

The study of stellar oscillations allows us to infer the properties of stellar interiors. Meanwhile, fundamental parameters such as mass and radius can be obtained by studying stars in binary systems. The synergy between binarity and asteroseismology can constrain the parameter space of stellar properties and facilitate the asteroseismic inference. On the other hand, binarity also introduces additional complexities such tides and mass transfer. From an observational perspective, we briefly review the recent advances in the study of tidal effects on stellar oscillations, focusing on upper main sequence stars (F-, A-, or OB- type). The effect can be roughly divided into two categories. The first one concerns the tidally excited oscillations (TEOs) in eccentric binaries where TEOs are mostly due to resonances between dynamical tides and gravity modes of the star. TEOs appear as orbital-harmonic oscillations on top of the eccentric ellipsoidal light curve variations (the “heartbeat” feature). The second category is regarding the self-excited oscillations perturbed by static tides in circularized and synchronized close binaries. It includes the tidal deformation of the propagation cavity and its effect on eigenfrequencies, eigenfunctions, and the pulsation alignment. We list binary systems that show these two types of tidal effect and summarize the orbital and pulsation observables. We also discuss the theoretical approaches used to model these tidal oscillations and relevant complications such as non-linear mode coupling and resonance locking. Further information can be extracted from the observations of these oscillations which will improve our understanding of tides. We also discuss the effect of mass transfer, the extreme result of tides, on stellar oscillations. We bring to the readers' attention: (1) oscillating stars undergoing mass accretion (A-, F-, and OB type pulsators and white dwarfs), for which the pulsation properties may be changed significantly by accretion; (2) post-mass transfer pulsators, which have undergone a stable or unstable Roche-Lobe overflow. These pulsators have great potential in probing detailed physical processes in stellar interiors and mass transfer, as well as in studying the binary star populations.

scholarly journals The Evolution of Pre-Main Sequence Close Binaries

1980 ◽  
Vol 88 ◽  
pp. 149-153 ◽  
Author(s):  
Jon K. West ◽  
Kwan-Yu Chen
Keyword(s):  
Mass Transfer ◽  
Binary System ◽  
Total Mass ◽  
Main Sequence ◽  
Binary Star ◽  
Computer Models ◽  
Close Binary ◽  
Close Binaries ◽  
Close Binary Star ◽  
Conventional Computer

Conventional computer models of close binary star systems usually start with at least one component on the main sequence. Models of premain sequence binaries have been computed to study mass transfer (Yamasaki 1971). However no pre-main sequence computations have been published that follow the evolutionary tracks of a binary system onto the main sequence, even though some observed systems appear to be premain sequence (Field 1969). The main purpose of this investigation is the evaluation of individual close binaries with a pre-main sequence model. The evaluation will be accomplished by comparing the positions of the observed binary on the Hertzsprung-Russell diagram with the evolutionary tracks generated by the pre-main sequence model. If both components appear to have the same age and fall near the tracks of the model, then the system is possibly pre-main sequence. Eleven semidetached binaries were considered, each with a total mass between 2.5 and 6 solar masses and with a period between 0.9 and 3.4 days.

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 Observational problems in determining the ages of open clusters

2008 ◽  
Vol 4 (S258) ◽  
pp. 141-152
Author(s):  
Elizabeth J. Jeffery
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Open Cluster ◽  
Dynamical Evolution ◽  
Stellar Populations ◽  
Statistical Technique ◽  
Open Clusters ◽  
Sequence Evolution ◽  
Data Set ◽  
Wide Range

AbstractOpen clusters have long been objects of interest in astronomy. As a good approximation of essentially pure stellar populations, they have proved very useful for studies in a wide range of astrophysically interesting questions, including stellar evolution and atmospheres, the chemical and dynamical evolution of our Galaxy, and the structure of our Galaxy. Of fundamental importance to our understanding of open clusters is accurate determinations of cluster ages. Currently there are two main techniques for independently determining the ages of stellar populations: main sequence evolution theory (via cluster isochrones) and white dwarf cooling theory. We will provide an overview of these two methods, the current level of agreement between them, as well as a look to the current state of increasing precision in the determination of each. Particularly I will discuss the comprehensive data set collection that is being done by the WIYN Open Cluster Study, as well as a new Bayesian statistical technique that has been developed by our group and its applications in improving and determining white dwarf ages of open clusters. I will review the so-called bright white dwarf technique, a new way of measuring cluster ages with just the bright white dwarfs. I will discuss the first application of the Bayesian technique to the Hyades, also demonstrating the first successful application of the bright white dwarf technique. These results bring the white dwarf age of the Hyades into agreement with the main sequence turn off age for the first time.

ON THE THEORY OF GAMMA RAY BURSTS AND HYPERNOVAE: THE BLACK HOLE SOFT X-RAY TRANSIENT SOURCES

2003 ◽  
Vol 18 (04) ◽  
pp. 527-576 ◽  
Author(s):  
CHANG-HWAN LEE ◽  
GERALD E. BROWN
Keyword(s):  
Mass Transfer ◽  
Black Hole ◽  
Mass Loss ◽  
Evolutionary History ◽  
Main Sequence ◽  
Gamma Ray ◽  
Supernova Explosion ◽  
Sequence Evolution ◽  
X Ray ◽  
Black Hole Binaries

We show that a common evolutionary history can produce the black hole binaries in the Galaxy in which the black holes have masses of ~ 5 - 10M⊙. In the black hole binaries with low-mass, ≲ 2.5M⊙ ZAMS (zero age main sequence) companions, the latter remain in main sequence during the active stage of soft X-ray transients (SXT's), most of them being of K or M classification. In two intermediate cases, IL Lupi and Nova Scorpii with ZAMS ~ 2.5M⊙ companions the orbits are greatly widened because of large mass loss in the explosion forming the black hole, and whereas these companions are in late main sequence evolution, they are close to evolving. Binaries with companion ZAMS masses ≳ 3M⊙ are initially "silent" until the companion begins evolving across the Herzsprung gap. We provide evidence that the narrower, shorter period binaries, with companions now in main sequence, are fossil remnants of gamma ray bursters (GRB's). We also show that the GRB is generally accompanied by a hypernova explosion (a very energetic supernova explosion). We further show that the binaries with evolved companions are good models for some of the ultraluminous X-ray sources (ULX's) recently seen by Chandra in other galaxies. The great regularity in our evolutionary history, especially the fact that most of the companions of ZAMS mass ≲ 2.5M⊙ remain in main sequences as K or M stars can be explained by the mass loss in common envelope evolution to be Case C; i.e. to occur only after core He burning has finished. Since our argument for Case C mass transfer is not generally understood in the community, we add an appendix, showing that with certain assumptions which we outline we can reproduce the regularities in the evolution of black hole binaries by Case C mass transfer.

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