scholarly journals Introduction & Overview to Symposium 240: Binary Stars as Critical Tools and Tests in Contemporary Astrophysics

2006 ◽  
Vol 2 (S240) ◽  
pp. 5-16 ◽  
Author(s):  
Edward F. Guinan ◽  
Petr Harmanec ◽  
William Hartkopf
Keyword(s):  
High Precision ◽  
Binary Stars ◽  
Binary Systems ◽  
New Technologies ◽  
Binary Star ◽  
Electromagnetic Spectrum ◽  
Multiple Star ◽  
Multiple Stars ◽  
Star Studies ◽  
Binary And Multiple Stars

AbstractAn overview is presented of the many new and exciting developments in binary and multiple star studies that were discussed at IAU Symposium 240. Impacts on binary and multiple star studies from new technologies, techniques, instruments, missions and theory are highlighted. It is crucial to study binary and multiple stars because the vast majority of stars (>60%) in our Galaxy and in other galaxies consist, not of single stars, but of double and multiple star systems. To understand galaxies we need to understand stars, but since most are members of binary and multiple star systems, we need to study and understand binary stars. The major advances in technology, instrumentation, computers, and theory have revolutionized what we know (and also don't know) about binary and multiple star systems. Data now available from interferometry (with milliarcsecond [mas] and sub-mas precisions), high-precision radial velocities (∼1-2 m/s) and high precision photometry (<1–2 milli-mag) as well as the wealth of new data that are pouring in from panoramic optical and infrared surveys (e.g., > 10,000 new binaries found since 1995), have led to a renaissance in binary star and multiple star studies. For example, advances have lead to the discovery of new classes of binary systems with planet and brown dwarf components (over 200 systems). Also, extremely valuable data about binary stars are available across the entire electromagnetic spectrum — from gamma-ray to IR space missions and from the ground using increasingly more powerful and plentiful optical and radio telescopes as well as robotic telescopes. In the immediate future, spectral coverage could even be extended beyond the radio to the first detection of gravity waves from interacting close binaries. Also, both the quality and quantity of data now available on binary and multiple stars are making it possible to gain unprecedented new insights into the structure, and formation and evolution of binary stars, as well as providing valuable astrophysical information (like precise stellar masses, radii, ages, luminosities and distances) to test and constrain current astrophysical theory. These major advances permit tests of current theories and ideas in stellar astrophysics and provide the foundations for the next steps in modeling and improvements in theory to be taken.

Astronomical Data Resources for Binary and Multiple Stars

2015 ◽  
Vol 24 (4) ◽  
pp. 446-452 ◽  
Author(s):  
D. Kovaleva
Keyword(s):  
Binary Stars ◽  
Stellar Population ◽  
Binary Star ◽  
Significant Part ◽  
Basic Data ◽  
Astronomical Data ◽  
Link Type ◽  
Multiple Stars ◽  
Star Database ◽  
Binary And Multiple Stars

AbstractBinary stars form a significant part of stellar population. They are registered and observed by a number of methods. This is the reason for variety of present-day resources of astronomical data dealing with binaries and multiples. The review of observational types of binary stars and of basic data resources for them is presented. The properties of stars within these types and possible relationships between them are discussed. The Binary star DataBase, BDB (http://bdb.inasan.ru), is presented as the resource joining data for all observational types of binaries. The problem of correct cross-identification of objects within binary and multiple stars is being solved in the frame of the Identification List of Binaries (ILB).

scholarly journals Spectroscopy, Photometry and Micro-Arcsec Astrometry of Binaries with The Gaia Space Mission and with the Rave Experiment

2004 ◽  
Vol 191 ◽  
pp. 251-258
Author(s):  
Tomaž Zwitter ◽  
Ulisse Munari
Keyword(s):  
Radial Velocity ◽  
Orbital Period ◽  
Binary Stars ◽  
Binary Systems ◽  
Large Fraction ◽  
Space Mission ◽  
Mission Design ◽  
Physical Parameters ◽  
Multiple Stars ◽  
Binary And Multiple Stars

AbstractThe GAIA astrometric mission of ESA will be very efficient in discovering binary and multiple stars with any orbital period, from minutes to millions of years. The main parameters of the revised mission design are presented. Next we estimate the fraction of binary stars discovered by means of astrometry, photometry and on-board spectroscopy. Finally we summarize observations that confirm the ability to measure physical parameters like masses, radii and spectroscopic distance from GAIA data alone. GAIA will fly only in 2010, but the radial velocity experiment (RAVE) has started this year. We show that its spectroscopic observations have the capacity to discover a large fraction of so far unknown binary systems.

scholarly journals Long-Term Coudé Radial-Velocity Studies With a 1.2-m Telescope

2001 ◽  
Vol 183 ◽  
pp. 283-288
Author(s):  
C.D. Scarfe
Keyword(s):  
Radial Velocity ◽  
Binary Stars ◽  
Star System ◽  
Standard Star ◽  
Stellar Spectra ◽  
Multiple Stars ◽  
Binary And Multiple Stars ◽  
Selection Of

AbstractI have used the 1.2-m telescope and coudé spectrograph of the Dominion Astrophysical Observatory for more than 30 years in a program of radial-velocity observations of binary stars. The program was begun with photographic plates as detectors, but for 20 years the primary detector has been the radial-velocity scanner, which cross-correlates stellar spectra with an artificial mask.Since some of the binaries under observation have periods of several years, the instrument’s stability is an important consideration. I have therefore been obliged to observe standard stars and asteroids to check its performance. These observations are of relevance to efforts to improve the IAU standard star system.I will describe the telescope, spectrograph and scanner, and will briefly discuss some of the results obtained for a selection of binary and multiple stars.

scholarly journals Statistics of Multiple Stars: Some Clues to Formation Mechanisms

2001 ◽  
Vol 200 ◽  
pp. 84-92 ◽  
Author(s):  
Andrei Tokovinin
Keyword(s):  
Observational Studies ◽  
Binary Systems ◽  
Close Binaries ◽  
Formation Mechanisms ◽  
Tidal Dissipation ◽  
Multiple Star ◽  
Star Catalogue ◽  
Multiple Stars ◽  
Available Information ◽  
Average Angle

The available information on the statistics of high multiplicity (3–6 components) systems is reviewed. The ratio of triple to binary systems is f3 ≍ 0.11, while fn ≍ 0.25 for higher n. Despite selection effects in the multiple star catalogue, the signatures of formation mechanisms are found in the distributions of period ratios and mass ratios. For example, the frequent occurrence of close sub-systems with periods less than 6 days can be explained by tidal dissipation in a 3-body system. In triple stars the angular momentum vectors of inner orbits are inclined to those of outer orbits by an average angle of 50°, hence the orbital spins are neither co-aligned nor completely random. Close binaries have a tendency to be found in higher-multiplicity systems, showing that close and wide binarity is statistically related. Future theoretical and observational studies are outlined.

scholarly journals Discovery and characterisation of long-period eclipsing binary stars from Kepler K2 campaigns 1, 2, and 3

2018 ◽  
Vol 616 ◽  
pp. A38 ◽  
Author(s):  
P. F. L. Maxted ◽  
R. J. Hutcheon
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Eclipsing Binaries ◽  
Star Model ◽  
Eclipsing Binary ◽  
Giant Stars ◽  
Long Period ◽  
Eclipsing Binary Stars

Context. The Kepler K2 mission now makes it possible to find and study a wider variety of eclipsing binary stars than has been possible to-date, particularly long-period systems with narrow eclipses. Aims. Our aim is to characterise eclipsing binary stars observed by the Kepler K2 mission with orbital periods longer than P ≈ 5.5 days. Methods. The ellc binary star model has been used to determine the geometry of eclipsing binary systems in Kepler K2 campaigns 1, 2 and 3. The nature of the stars in each binary is estimated by comparison to stellar evolution tracks in the effective temperature – mean stellar density plane. Results. 43 eclipsing binary systems have been identified and 40 of these are characterised in some detail. The majority of these systems are found to be late-type dwarf and sub-giant stars with masses in the range 0.6–1.4 solar masses. We identify two eclipsing binaries containing red giant stars, including one bright system with total eclipses that is ideal for detailed follow-up observations. The bright B3V-type star HD 142883 is found to be an eclipsing binary in a triple star system. We observe a series of frequencies at large multiples of the orbital frequency in BW Aqr that we tentatively identify as tidally induced pulsations in this well-studied eccentric binary system. We find that the faint eclipsing binary EPIC 201160323 shows rapid apsidal motion. Rotational modulation signals are observed in 13 eclipsing systems, the majority of which are found to rotate non-synchronously with their orbits. Conclusions. The K2 mission is a rich source of data that can be used to find long period eclipsing binary stars. These data combined with follow-up observations can be used to precisely measure the masses and radii of stars for which such fundamental data are currently lacking, e.g., sub-giant stars and slowly-rotating low-mass stars.

scholarly journals Origin of the orbital period change in contact binary stars

2019 ◽  
Vol 28 (06) ◽  
pp. 1950044 ◽  
Author(s):  
V. V. Sargsyan ◽  
H. Lenske ◽  
G. G. Adamian ◽  
N. V. Antonenko
Keyword(s):  
Orbital Period ◽  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Period Change ◽  
Mass Asymmetry ◽  
Contact Binary Stars ◽  
Contact Binary ◽  
Energy Formula ◽  
Orbital Periods

The evolution of contact binary star systems in mass asymmetry (transfer) coordinate is considered. The orbital period changes are explained by an evolution in mass asymmetry towards the symmetry (symmetrization of binary system). It is predicted that decreasing and increasing orbital periods are related, respectively, with the nonoverlapping and overlapping stage of the binary star during its symmetrization. A huge amount of energy [Formula: see text][Formula: see text]J is converted from the potential energy into internal energy of the stars during the symmetrization. As shown, the merger of stars in the binary systems, including KIC 9832227, is energetically an unfavorable process. The sensitivity of the calculated results to the values of total mass and orbital angular momentum is analyzed.

scholarly journals Circumbinary Planets and the SOLARIS Project

2011 ◽  
Vol 7 (S282) ◽  
pp. 111-116 ◽  
Author(s):  
Maciej Konacki ◽  
Piotr Sybilski ◽  
Stanisław K. Kozłowski ◽  
Milena Ratajczak ◽  
Krzysztof G. Hełminiak
Keyword(s):  
South America ◽  
Binary Stars ◽  
Extrasolar Planets ◽  
Binary Star ◽  
Multiple Star ◽  
Eclipsing Binary ◽  
Stellar Astronomy ◽  
Eclipsing Binary Stars ◽  
Spectroscopic Binary ◽  
Circumbinary Planets

AbstractExtrasolar planets in binary and multiple star systems have become a noticeable niche with about 50 planets among over 500 known. Here we however focus on a particular subset of exoplanets in binary star systems — circumbinary planets. They have the unique advantage that a search for circumbinary planets does also significantly contribute to the understanding of their parent stars. We review what is currently known about circumbinary planets and then introduce our two projects aimed at detecting circumbinary planets: The TATOOINE project to find circumbinary planets around non-eclipsing double-lined spectroscopic binary stars with precision radial velocities, and the SOLARIS project to detect circumbinary planets with the timing of eclipses of eclipsing binary stars. For the SOLARIS project, we were granted 2.6 million USD to establish a network of at least four robotic 0.5-m telescopes on three continents (Australia, Africa and South America) to carry out precision photometry of a sample of eclipsing binary stars. We expect that both projects will have a large impact also on the observational stellar astronomy.

BSDB: A New Consistent Designation Scheme for Identifying Objects in Binary and Multiple Stars

2015 ◽  
Vol 24 (2) ◽  
Author(s):  
D. A. Kovaleva ◽  
O. Yu. Malkov ◽  
P. V. Kaygorodov ◽  
A. V. Karchevsky ◽  
N. N. Samus
Keyword(s):  
Binary Star ◽  
Multiple Systems ◽  
Multiple Stars ◽  
Star Database ◽  
Binary And Multiple Stars

AbstractThe new consistent scheme for designation of objects in binary and multiple systems, BSDB, is described. It was developed in the frame of the Binary star DataBase, BDB (

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 Isolated Binaries and Triples in N-body Systems

1995 ◽  
Vol 164 ◽  
pp. 372-372
Author(s):  
J. Anosova ◽  
L. Kiseleva
Keyword(s):  
Globular Cluster ◽  
Binary Stars ◽  
Star Clusters ◽  
Dynamical Evolution ◽  
Time Interval ◽  
Galactic Field ◽  
Multiple Stars ◽  
Binary And Multiple Stars ◽  
Marked Tendency ◽  
Triple Stars

Stars show a marked tendency to form the systems of different multiplicity starting from the smallest systems as binary and triple stars up to clusters with a significantly larger number of objects (N ~ 107 for globular cluster s). Different investigators have used different methods of binary stars identificati on but modern observations give a frequency of binary and multiple stars in the Galactic field up to 70% Binary and multiple stars are also often present within star clusters. It is therefore very important to be able to identify such systems as rather isolated substructures in which the dynamical evolution is not significantly affected by other stars (at least, during some considerab le time interval).

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