scholarly journals Non-synchronous rotations in massive binary systems

2018 ◽  
Vol 618 ◽  
pp. A174
Author(s):  
C. Putkuri ◽  
R. Gamen ◽  
N. I. Morrell ◽  
S. Simón-Díaz ◽  
R. H. Barbá ◽  
...  
Keyword(s):  
Binary Systems ◽  
Massive Stars ◽  
Spectroscopic Binaries ◽  
Evolutionary Status ◽  
Multiple Systems ◽  
Orbital Parameters ◽  
Link Type ◽  
Tidal Forces ◽  
Relative Separation ◽  
Massive Binary Systems

Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as double-lined spectroscopic binaries and among these, the OWN Survey has detected a non-negligible number whose components show very different spectral line broadening (i.e., projected rotational velocities). This fact raises a discussion about the contributing processes, such as angular-momentum transfer and tidal forces. Aims. We seek to constrain the physical and evolutionary status of one of such systems, the O+O binary HD 93343. Methods. We analyzed a series of high-resolution multiepoch optical spectra to determine the orbital parameters, projected rotational velocities, and evolutionary status of the system. Results. HD 93343 is a binary system comprised of two O7.5 Vz stars that each have minimum masses of approximately 22 M⊙ in a wide and eccentric orbit (e = 0.398±0.004; P = 50.432±0.001 d). Both stars have very similar stellar parameters, and hence ages. As expected from the qualitative appearance of the combined spectrum of the system, however, these stars have very different projected rotational velocities (~65 and ~325 km s−1, respectively). Conclusions. The orbits and stellar parameters obtained for both components seem to indicate that their youth and relative separation is enough to discard the effects of mass transfer and tidal friction. Thus, non-synchronization should be intrinsic to their formation.

Massive Binaries in the Magellanic Clouds

2005 ◽  
Vol 13 ◽  
pp. 463-463
Author(s):  
Virpi S. Niemela
Keyword(s):  
Binary Stars ◽  
Present Status ◽  
Binary Systems ◽  
Massive Stars ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Stellar Winds ◽  
Multiple Systems ◽  
Orbital Parameters

We present results of our ongoing observing program on search and studies of massive stars (O and WR type) in binary systems in our neighbor galaxies, the Magellanic Clouds. Radial velocity orbits are presented for two new binaries, one in the Small Magellanic Cloud and another in the Large Magellanic Cloud, and improved orbits for previously known systems. We compare orbital parameters of selected binaries containing O and WR type components. We also discuss the present status of knowledge for massive binary stars in the Magellanic Clouds and the problems encountered in their orbital studies such as stellar winds the ubiquitous tendency to be born in multiple systems.

scholarly journals MONOS: Multiplicity Of Northern O-type Spectroscopic systems

2019 ◽  
Vol 626 ◽  
pp. A20 ◽  
Author(s):  
J. Maíz Apellániz ◽  
E. Trigueros Páez ◽  
I. Negueruela ◽  
R. H. Barbá ◽  
S. Simón-Díaz ◽  
...  
Keyword(s):  
Massive Stars ◽  
Dynamical Evolution ◽  
Eclipsing Binaries ◽  
Spectroscopic Binaries ◽  
High Resolution Spectroscopy ◽  
Single Observation ◽  
Multiple Systems ◽  
Additional Information ◽  
Public Archives ◽  
First Time

Context. Multiplicity in massive stars is key to understanding the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. Aims. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with δ >  −20°. In this first paper we describe the sample and provide spectral classifications and additional information for objects with previous spectroscopic and/or eclipsing binary orbits. In future papers we will test the validity of previous solutions and calculate new spectroscopic orbits. Methods. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that obtains blue-violet R ∼ 2500 spectroscopy of thousands of massive stars, and LiLiMaRlin, a library of libraries of high-resolution spectroscopy of massive stars obtained from four different surveys (CAFÉ-BEANS, OWN, IACOB, and NoMaDS) and additional data from our own observing programs and public archives. We have also used lucky images obtained with AstraLux. Results. We present homogeneous spectral classifications for 92 O-type spectroscopic multiple systems and ten optical companions, many of them original. We discuss the visual multiplicity of each system with the support of AstraLux images and additional sources. For eleven O-type objects and for six B-type objects we present their first GOSSS spectral classifications. For two known eclipsing binaries we detect double absorption lines (SB2) or a single moving line (SB1) for the first time, to which we add a third system reported by us recently. For two previous SB1 systems we detect their SB2 nature for the first time and give their first separate spectral classifications, something we have also done for a third object just recently identified as a SB2. We also detect nine new astrometric companions and provide updated information on several others. We emphasize the results for two stars: for σ Ori AaAbB we provide spectral classifications for the three components with a single observation for the first time thanks to a lucky spectroscopy observation obtained close to the Aa,Ab periastron and for θ1 Ori CaCb we add it to the class of Galactic Of?p stars, raising the number of its members to six. Our sample of O-type spectroscopic binaries contains more triple- or higher-order systems than double systems.

scholarly journals Line-Profile Variations on Massive Binary Systems: Determining η Carinae Orbital Parameters

2006 ◽  
Vol 2 (S240) ◽  
pp. 198-201
Author(s):  
D. Falceta-Gonçalves ◽  
Z. Abraham ◽  
V. Jatenco-Pereira
Keyword(s):  
Line Profile ◽  
Binary Systems ◽  
Spectral Lines ◽  
Stream Velocity ◽  
Interaction Zone ◽  
Orbital Inclination ◽  
Orbital Parameters ◽  
Massive Binary Systems ◽  
Shock Fronts ◽  
Synthetic Line

AbstractWhen the winds of two massive stars orbiting each other collide, an interaction zone is created consisting of two shock fronts at both sides of a contact surface. During the cooling process, elements may recombine generating spectral lines. These lines may be Doppler shifted, as the gas stream flows over the interaction zone. To calculate the stream velocity projected into the line of sight we use a simplified conical geometry for the shock fronts and, to determine the synthetic line profile, we have to sum the amount of emitting gas elements with the same Doppler shifted velocity. We show that the stellar mass loss rates and wind velocities, and the orbital inclination and eccentricity, are the main parameters on this physical process. By comparing observational data to the synthetic line profiles it is possible to determine these parameters. We tested this process to Brey 22 WR binary system, and applied to the enigmatic object of η Carinae.

scholarly journals Is there a Connection Between Non-Synchronous Rotation and X-Ray Emission in Massive Binary Systems?

2004 ◽  
Vol 215 ◽  
pp. 163-165 ◽  
Author(s):  
Sinhué Haro ◽  
Juan Antonio Juárez ◽  
Gloria Koenigsberger
Keyword(s):  
Mass Loss ◽  
Orbital Period ◽  
Binary Systems ◽  
X Ray ◽  
Rotating Systems ◽  
Tidal Forces ◽  
Synchronous Rotation ◽  
Massive Binary Systems ◽  
Loss Rates

A correlation between orbital period and log(LX/Lbol) is found for a sample of B-type binary systems. We suggest that wind-wind collisions are the likely mechanism for generating the X-ray emission, and that the mass-loss rates may be enhanced in non-synchronously rotating systems due to the oscillations that are excited by the tidal forces.

scholarly journals The Tarantula Massive Binary Monitoring

2020 ◽  
Vol 634 ◽  
pp. A119 ◽  
Author(s):  
L. Mahy ◽  
L. A. Almeida ◽  
H. Sana ◽  
J. S. Clark ◽  
A. de Koter ◽  
...  
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Spectroscopic Binaries ◽  
Systematic Analysis ◽  
Orbital Parameters ◽  
The Individual ◽  
30 Doradus ◽  
Dynamical Masses

Context. A high fraction of massive stars are found to be binaries but only a few of them are reported as photometrically variable. By studying the populations of double-lined spectroscopic binaries in the 30 Doradus region, we found a subset of them that have photometry from the OGLE project and that display variations in their light curves related to orbital motions. Aims. The goal of this study is to determine the dynamical masses and radii of the 26 binary components in order to investigate the mass-discrepancy problem and to provide an empirical mass-luminosity relation for the Large Magellanic Cloud (LMC). Methods. We use the PHOEBE programme to perform a systematic analysis of the OGLE V and I light curves obtained for 13 binary systems in the 30 Doradus region. We adopt the effective temperatures, and orbital parameters derived previously to obtain the inclinations of the systems and the parameters of the individual components. Results. Three systems display eclipses in their light curves, while the others only display ellipsoidal variations. We classify two systems as over-contact, five as semi-detached, and four as detached. The two remaining systems have uncertain configurations due to large uncertainties on their inclinations. The fact that systems display ellipsoidal variations has a significant impact on the inclination errors. From the dynamical masses, luminosities, and radii, we provide LMC-based empirical mass-luminosity and mass-radius relations, and we compare them to other relations given for the Galaxy, the LMC, and the Small Magellanic Cloud. These relations differ for different mass ranges, but do not seem to depend on the metallicity regimes. We also compare the dynamical, spectroscopic, and evolutionary masses of the stars in our sample. While the dynamical and spectroscopic masses agree with each other, the evolutionary masses are systematically higher, at least for stars in semi-detached systems. This suggests that the mass discrepancy can be partly explained by past or ongoing interactions between the stars.

scholarly journals The Tarantula Massive Binary Monitoring

2020 ◽  
Vol 634 ◽  
pp. A118 ◽  
Author(s):  
L. Mahy ◽  
H. Sana ◽  
M. Abdul-Masih ◽  
L. A. Almeida ◽  
N. Langer ◽  
...  
Keyword(s):  
Binary Systems ◽  
Tidal Mixing ◽  
Spectroscopic Binaries ◽  
Type Star ◽  
Evolutionary Models ◽  
Test Bed ◽  
Contact Phase ◽  
Single Star ◽  
Massive Binary Systems ◽  
The Individual

Context. Accurate stellar parameters of individual objects in binary systems are essential to constrain the effects of binarity on stellar evolution. These parameters serve as a prerequisite to probing existing and future theoretical evolutionary models. Aims. We aim to derive the atmospheric parameters of the 31 double-lined spectroscopic binaries in the Tarantula Massive Binary Monitoring sample. This sample, composed of detached, semi-detached and contact systems with at least one of the components classified as an O-type star, is an excellent test-bed to study how binarity can impact our knowledge of the evolution of massive stars. Methods. In the present paper, 32 epochs of FLAMES/GIRAFFE spectra are analysed by using spectral disentangling to construct the individual spectra of 62 components. We then apply the CMFGEN atmosphere code to determine their stellar parameters and their helium, carbon, and nitrogen surface abundances. Results. Among the 31 systems that we study in the present paper, we identify between 48 and 77% of them as detached, likely pre-interacting systems, 16% as semi-detached systems, and between 5 and 35% as systems in or close to contact phase. Based on the properties of their components, we show that the effects of tides on chemical mixing are limited. Components on longer-period orbits show higher nitrogen enrichment at their surface than those on shorter-period orbits, in contrast to expectations of rotational or tidal mixing, implying that other mechanisms play a role in this process. For semi-detached systems, components that fill their Roche lobe are mass donors. They exhibit higher nitrogen content at their surface and rotate more slowly than their companions. By accreting new material, their companions spin faster and are likely rejuvenated. Their locations in the N − v sin i diagram tend to show that binary products are good candidates to populate the two groups of stars (slowly rotating, nitrogen-enriched objects and rapidly rotating non-enriched objects) that cannot be reproduced through single-star population synthesis. Finally, we find no peculiar surface abundances for the components in (over-)contact systems, as has been suggested by evolutionary models for tidal mixing. Conclusions. This sample, consisting of 31 massive binary systems, is the largest sample of binaries composed of at least one O-type star to be studied in such a homogeneous way by applying spectral disentangling and atmosphere modelling. The study of these objects gives us strong observational constraints to test theoretical binary evolutionary tracks.

scholarly journals Fundamental parameters of massive stars in multiple systems: The cases of HD 17505A and HD 206267A

2018 ◽  
Vol 614 ◽  
pp. A60 ◽  
Author(s):  
F. Raucq ◽  
G. Rauw ◽  
L. Mahy ◽  
S. Simón-Díaz
Keyword(s):  
Binary Systems ◽  
Massive Stars ◽  
Model Atmosphere ◽  
Roche Lobe ◽  
Binary Interaction ◽  
Single Star ◽  
Multiple Systems ◽  
Fundamental Parameters ◽  
Cno Abundances ◽  
The Impact

Context. Many massive stars are part of binary or higher multiplicity systems. The present work focusses on two higher multiplicity systems: HD 17505A and HD 206267A. Aims. Determining the fundamental parameters of the components of the inner binary of these systems is mandatory to quantify the impact of binary or triple interactions on their evolution. Methods. We analysed high-resolution optical spectra to determine new orbital solutions of the inner binary systems. After subtracting the spectrum of the tertiary component, a spectral disentangling code was applied to reconstruct the individual spectra of the primary and secondary. We then analysed these spectra with the non-LTE model atmosphere code CMFGEN to establish the stellar parameters and the CNO abundances of these stars. Results. The inner binaries of these systems have eccentric orbits with e ~ 0.13 despite their relatively short orbital periods of 8.6 and 3.7 days for HD 17505Aa and HD 206267Aa, respectively. Slight modifications of the CNO abundances are found in both components of each system. The components of HD 17505Aa are both well inside their Roche lobe, whilst the primary of HD 206267Aa nearly fills its Roche lobe around periastron passage. Whilst the rotation of the primary of HD 206267Aa is in pseudo-synchronization with the orbital motion, the secondary displays a rotation rate that is higher. Conclusions. The CNO abundances and properties of HD 17505Aa can be explained by single star evolutionary models accounting for the effects of rotation, suggesting that this system has not yet experienced binary interaction. The properties of HD 206267Aa suggest that some intermittent binary interaction might have taken place during periastron passages, but is apparently not operating anymore.

scholarly journals Physical parameters of close binary systems: VIII

2021 ◽  
Author(s):  
K Gazeas ◽  
S Zola ◽  
A Liakos ◽  
B Zakrzewski ◽  
S M Rucinski ◽  
...  
Keyword(s):  
Binary Systems ◽  
Extreme Values ◽  
Close Binary ◽  
Physical Parameters ◽  
Evolutionary Status ◽  
Mass Ratio ◽  
Orbital Parameters ◽  
Contact Binaries ◽  
Contact Binary ◽  
Orbital Periods

Abstract This paper presents the results of a combined spectroscopic and photometric study of 20 contact binary systems: HV Aqr, OO Aql, FI Boo, TX Cnc, OT Cnc, EE Cet, RW Com, KR Com, V401 Cyg, V345 Gem, AK Her, V502 Oph, V566 Oph, V2612 Oph, V1363 Ori, V351 Peg, V357 Peg, Y Sex, V1123 Tau and W UMa, which was conducted in the frame of the W UMa Project. Together with 51 already covered by the project and an additional 67 in the existing literature, these systems bring the total number of contact binaries with known combined spectroscopic and photometric solutions to 138. It was found that mass, radius and luminosity of the components follow certain relations along the MS and new empirical power relations are extracted. We found that 30 per cent of the systems in the current sample show extreme values in their parameters, expressed in their mass ratio or fill-out factor. This study shows that, among the contact binary systems studied, some have an extremely low mass ratio (q<0.1) or an ultra-short orbital period (Porb <0.25 d), which are expected to show evidence of mass transfer progress. The evolutionary status of these components is discussed with the aid of correlation diagrams and their physical and orbital parameters compared to those in the entire sample of known contact binaries. The existence of very short orbital periods confirms the very slow nature of the merging process, which seems to explain why their components still exist as MS stars in contact configurations even after several Gyr of evolution.

scholarly journals The CARMENES search for exoplanets around M dwarfs

2018 ◽  
Vol 619 ◽  
pp. A32 ◽  
Author(s):  
D. Baroch ◽  
J. C. Morales ◽  
I. Ribas ◽  
L. Tal-Or ◽  
M. Zechmeister ◽  
...  
Keyword(s):  
Binary Systems ◽  
Spectroscopic Binaries ◽  
M Dwarfs ◽  
Dwarf Stars ◽  
Double Line ◽  
Orbital Parameters ◽  
Rotation Periods ◽  
Spectroscopic Binary ◽  
M Dwarf Stars ◽  
M Dwarf

Context. The CARMENES spectrograph is surveying ∼300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Aims. Using spectroscopic observations, we determine the orbital and physical properties of nine new double-line spectroscopic binary systems by analysing their radial velocity curves. Methods. We use two-dimensional cross-correlation techniques to derive the radial velocities of the targets, which are then employed to determine the orbital properties. Photometric data from the literature are also analysed to search for possible eclipses and to measure stellar variability, which can yield rotation periods. Results. Out of the 342 stars selected for the CARMENES survey, 9 have been found to be double-line spectroscopic binaries, with periods ranging from 1.13 to ∼8000 days and orbits with eccentricities up to 0.54. We provide empirical orbital properties and minimum masses for the sample of spectroscopic binaries. Absolute masses are also estimated from mass-luminosity calibrations, ranging between ∼0.1 and ∼0.6 M⊙. Conclusions. These new binary systems increase the number of double-line M dwarf binary systems with known orbital parameters by 15%, and they have lower mass ratios on average.

scholarly journals Formation of massive binaries

2003 ◽  
Vol 212 ◽  
pp. 80-90 ◽  
Author(s):  
Hans Zinnecker
Keyword(s):  
Stellar Evolution ◽  
Massive Stars ◽  
Star Clusters ◽  
Young Star ◽  
Spectroscopic Binaries ◽  
Stellar Clusters ◽  
Multiple Systems ◽  
Short Period ◽  
Young Star Clusters ◽  
Runaway Stars

The formation of massive stars is one of the major unsolved problems in stellar astrophysics. However, only few if any of these are found as single stars, on average massive stars have more than one companion. Many of them are born in dense stellar clusters and several clusters have an excess of massive short-period spectroscopic binaries, with severe implication for binary-related stellar evolution including mergers, and also for the origin of massive runaway stars. The multiplicity of massive stars seems to increase with increasing primary mass and with increasing density of young star clusters. These observations suggest that massive binary and multiple systems originate mainly from dynamical gravitational interactions and accretion-induced protostellar collisions in dense clusters. If true, the binary properties of massive stars in less dense OB associations should be less extreme. This prediction should be tested by future observations. The paper reviews both the latest observations and theoretical ideas related to the origin of massive binaries. It concludes with a speculation on how the binary properties might change with metallicity (e.g., LMC/SMC).

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