scholarly journals Simulating the formation of η Carinae’s surrounding nebula through unstable triple evolution and stellar merger-induced eruption

2021 ◽  
Vol 503 (3) ◽  
pp. 4276-4296
Author(s):  
Ryosuke Hirai ◽  
Philipp Podsiadlowski ◽  
Stanley P Owocki ◽  
Fabian R N Schneider ◽  
Nathan Smith
Keyword(s):  
Massive Star ◽  
Theoretical Calculations ◽  
Strong Support ◽  
Close Binary ◽  
Triple Systems ◽  
Surrounding Structure ◽  
Mass Outflow ◽  
Key Aspects ◽  
Mass Ejection ◽  
Primary Agent

ABSTRACT η Carinae is an extraordinary massive star famous for its 19th century Great Eruption and the surrounding Homunculus nebula ejected in that event. The cause of this eruption has been the centre of a long-standing mystery. Recent observations, including light-echo spectra of the eruption, suggest that it most likely resulted from a stellar merger in an unstable triple system. Here we present a detailed set of theoretical calculations for this scenario; from the dynamics of unstable triple systems and the mass ejection from close binary encounters, to the mass outflow from the eruption caused by the stellar merger and the post-merger wind phase. In our model the bipolar post-merger wind is the primary agent for creating the Homunculus, as it sweeps up external eruption ejecta into a thin shell. Our simulations reproduce many of the key aspects of the shape and kinematics of both the Homunculus nebula and its complex surrounding structure, providing strong support for the merger-in-a-triple scenario.

scholarly journals The Influence of Binarity on Stellar Activity

2006 ◽  
Vol 2 (S240) ◽  
pp. 442-452 ◽  
Author(s):  
Katalin Oláh
Keyword(s):  
Binary Systems ◽  
Magnetic Energy ◽  
Theoretical Calculations ◽  
Deep Convection ◽  
Magnetic Activity ◽  
Close Binary ◽  
Convective Envelope ◽  
Flux Tubes ◽  
Gravitational Forces ◽  
Magnetic Flux Tubes

AbstractActivity of late type stars is enhanced by fast rotation, which is maintained in nearly synchronized close binary systems. Magnetic activity originates in the deep convection zones of stars from where magnetic flux tubes emerge to their surfaces. The gravitational forces in binaries help the clustering of activity features giving rise to active longitudes. These preferred longitudes are observed in binaries from dwarfs to giants. Differential rotation is found in many active stars that are components of binary systems. If these binaries are circularized and nearly synchronized, then there will be a corotation latitude in their surfaces, and its position can be determined by observations and by theoretical calculations. Enhanced activity in binaries could have a reverse effect as well: strong magnetism in a binary component can modify the orbital period by the cyclic exchange of kinetic and magnetic energy in its convective envelope.

scholarly journals Interacting Binaries as Be Stars

1987 ◽  
Vol 92 ◽  
pp. 451-455
Author(s):  
Mirek J. Plavec
Keyword(s):  
Spectral Type ◽  
Binary Stars ◽  
Emission Lines ◽  
Close Binary ◽  
High Electron ◽  
Be Stars ◽  
Close Binary Stars ◽  
High Ionization ◽  
Mass Outflow ◽  
Balmer Lines

AbstractSemidetached close binary stars of the Algol type often have primary components of spectral type A0 or earlier and display emission at Hα (sometimes also at higher Balmer lines). They are therefore Be stars. Many binaries of this type are not eclipsing and must look like “ordinary” Be stars. We have discovered high-ionization emission lines of N V, C IV, Si IV, Fe III, etc. in the ultraviolet spectra of totally eclipsing Algols. They probably originate in circumstellar turbulent regions at fairly high electron temperatures, of the order of 100 000 K. They are not detectable in most non-eclipsing systems, but may be there and may play an important role in the dynamics of accretion and mass outflow from the systems.

scholarly journals High mass X-ray binaries as progenitors of gravitational wave sources

2018 ◽  
Vol 14 (S346) ◽  
pp. 417-425 ◽  
Author(s):  
Jakub Klencki ◽  
Gijs Nelemans
Keyword(s):  
Mass Transfer ◽  
Massive Star ◽  
Formation Rate ◽  
Point Of View ◽  
High Mass ◽  
Close Binary ◽  
X Ray ◽  
Orbital Periods ◽  
X Ray Binaries ◽  
Hubble Time

AbstractX-ray binaries with black hole (BH) accretors and massive star donors at short orbital periods of a few days can evolve into close binary BH (BBH) systems that merge within the Hubble time. From an observational point of view, upon the Roche-lobe overflow such systems will most likely appear as ultra-luminous X-ray sources (ULXs). To study this connection, we compute the mass transfer phase in systems with BH accretors and massive star donors (M > 15 Mʘ) at various orbital separations and metallicities. In the case of core-hydrogen and core-helium burning donors (cases A and C of mass transfer) we find the typical duration of super-Eddington mass transfer of up to 106 and 105 yr, with rates of 10−6 and 10−5Mʘ yr-1, respectively. Given that roughly 0.5 ULXs are found per unit of star formation rate, we estimate the rate of BBH mergers from stable mass transfer evolution to be at most 10 Gpc−3 yr−1.

scholarly journals CSI in Supernova Remnants

2017 ◽  
Vol 12 (S331) ◽  
pp. 81-85
Author(s):  
You-Hua Chu
Keyword(s):  
Supernova Remnants ◽  
Hubble Space Telescope ◽  
Orbital Plane ◽  
Large Magellanic Cloud ◽  
Close Binary System ◽  
Close Binary ◽  
Binary Interaction ◽  
Space Telescope ◽  
Multi Wavelength ◽  
Mass Ejection

AbstractSupernovae (SNe) explode in environments that have been significantly modified by the SN progenitors. For core-collapse SNe, the massive progenitors ionize the ambient interstellar medium (ISM) via UV radiation and sweep the ambient ISM via fast stellar winds during the main sequence phase, replenish the surroundings with stellar material via slow winds during the luminous blue variable (LBV) or red supergiant (RSG) phase, and sweep up the circumstellar medium (CSM) via fast winds during the Wolf-Rayet (WR) phase. If a massive progenitor was in a close binary system, the binary interaction could have caused mass ejection in certain preferred directions, such as the orbital plane, and even bipolar outflow/jet. As a massive star finally explodes, the SN ejecta interacts first with the CSM that was ejected and shaped by the star itself. As the newly formed supernova remnant (SNR) expands further, it encounters interstellar structures that were shaped by the progenitor from earlier times. Therefore, the structure and evolution of a SNR is largely dependent on the initial mass and close binarity of the SN progenitor. The Large Magellanic Cloud (LMC) has an excellent sample of over 50 confirmed SNRs that are well resolved by Hubble Space Telescope, Chandra X-ray Observatory, and Spitzer Space Telescope. These multi-wavelength observations allow us to conduct stellar forensics in SNRs and understand the wide variety of morphologies and physical properties of SNRs observed.

scholarly journals The Disruption of EUV Coronal Loops Following a Mass Ejection Transient

1980 ◽  
Vol 91 ◽  
pp. 241-244
Author(s):  
E. J. Schmahl
Keyword(s):  
White Light ◽  
Coronal Loops ◽  
X Rays ◽  
Transient Event ◽  
Mass Outflow ◽  
Coronal Transient ◽  
Loop Prominence ◽  
Mass Ejection

A classic filament disruption/coronal transient event ocurred on 10 January 1974. After the prominence liftoff, “gradual” x-rays were recorded by Solrad 9. A white light coronal ejection, interpreted as a loop seen edge-on, followed. During the mass outflow, Hα loops formed at the original site of the prominence. The loops appeared also in EUV spectroheliograms, and rose rapidly before vanishing abruptly. During the disintegration of the loops the apices showed great enhancements and vertical spike structures. The overall behavior of this loop prominence system is compatible with reconnection models.

scholarly journals The Binaries from Unstable Triples. Dynamical Processes of Formation

1989 ◽  
Vol 8 ◽  
pp. 143-144
Author(s):  
Joanna P. Anosova
Keyword(s):  
Computer Simulations ◽  
Dynamical Evolution ◽  
Close Binary ◽  
Close Binaries ◽  
State University ◽  
Dynamical Processes ◽  
Triple Systems ◽  
Gravitational Problem ◽  
Three Body

The dynamical processes of formation, evolution and disruption of binaries may be effectively studied by computer simulations in the N > 3-body gravitational problem. As a result of analysis of these investigations of diverse authors, the classification of the dynamical processes of formation of wide and close binaries may be proposed (see Table 1). This Table shows the following general processes: I-triple approaches of the single bodies; II-approaches of binaries with single bodies; Ill-escape from physical triples. The actions of these processes, and kinetics of a frequency of binaries in general field were studied at the Astronomical Observatory of the Leningrad State University (1965-1988) by computer simulations in the three-body problem. More than 3.104 orbits with negative total energy E < 0 and 5.104 with E > 0 have been run on the computers. The film “Dynamical evolution of triple systems” was produced. Part I of this movie shows the evolution of the unstable non-hierarchical triplet as well as the processes of formation, evolution, and disruption of temporary wide and final close binaries inside the physical triples. Part II of film presents in detail the trajectories of the bodies on the triple approaches of “fly-by”-and of “exchange”-types. The triple approach of “fly-by”-type results often in an escape from triple as well as the formation of final close binary. The triple approach of “exchange”-type consists as a rule of a few close double approaches of bodies and rarely results in an escape from triplet, it results in formation of temporary wide binary inside triplet. Part III of movie presents the trajectories of the different-mass bodies: an escape of the minimum-mass body, the intermediate-mass body, and the maximum-mass body as well as a formation of binaries with different-mass components.

scholarly journals Criteria of Dynamical Isolation of Binaries and Multiples

1996 ◽  
Vol 169 ◽  
pp. 531-532
Author(s):  
Ludmila Kiseleva ◽  
Joanna Anosova
Keyword(s):  
Strong Influence ◽  
Dynamical Behavior ◽  
Close Binary ◽  
Dynamical Processes ◽  
Objective Criterion ◽  
Triple Systems ◽  
Mass Ratios ◽  
Hierarchical Stability ◽  
New Criterion

In order to obtain an objective criterion for dynamical isolation of binaries within systems of large multiplicity we study numerically the dynamical behavior and average parameters of stable hierarchical triple systems containing a close binary. Using the new criterion for hierarchical stability of triple systems with different mass ratios of components (Kiseleva, Eggleton, Anosova 1994; Kiseleva, Eggleton, Orlov 1994) the perturbing force from the outer body on the close inner binary is estimated. On this basis, the critical separations are obtained when both inner and outer orbits are practically not perturbed. Because the dispersion of masses has a very strong influence on dynamical processes in N-body systems, mass ratios of subsystems, and sometimes within subsystems, should always be taken into account.

scholarly journals On the formation of runaway stars BN and x in the Orion Nebula Cluster

2018 ◽  
Vol 612 ◽  
pp. L7 ◽  
Author(s):  
J. P. Farias ◽  
J. C. Tan
Keyword(s):  
Star Formation ◽  
Massive Star ◽  
Close Binary ◽  
Orion Nebula ◽  
Massive Star Formation ◽  
Star Forming ◽  
Runaway Stars

We explore scenarios for the dynamical ejection of stars BN and x from source I in the Kleinmann-Low nebula of the Orion Nebula Cluster (ONC), which is important because it is the closest region of massive star formation. This ejection would cause source I to become a close binary or a merger product of two stars. We thus consider binary-binary encounters as the mechanism to produce this event. By running a large suite of N-body simulations, we find that it is nearly impossible to match the observations when using the commonly adopted masses for the participants, especially a source I mass of 7 M⊙. The only way to recreate the event is if source I is more massive, that is, ~20 M⊙. However, even in this case, the likelihood of reproducing the observed system is low. We discuss the implications of these results for understanding this important star-forming region.

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.

Sign in / Sign up

Export Citation Format

Share Document