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Mauri Valtonen - One of the best experts on this subject based on the ideXlab platform.
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Mass Ratios in Wide Binary Stars
The Astrophysical Journal, 1997Co-Authors: Mauri ValtonenAbstract:The mass ratio distribution N(q) in wide Binary Stars has been found by Abt to depend on the spectral type of the primary. The Stars with an O-type primary are rather equal in mass in comparison with binaries that have solar-type primaries. We investigate whether this results from the theory of stellar dynamics if the Binary Stars are remnants of three-body encounters. In case of solar-type primaries, the theoretical distribution is close to N(q) ∝ q-1, as is found also in a careful analysis of observations by Trimble. However, the distribution for the O-type binaries has no simple explanation in the three-body theory, and it is likely that the observed distribution is closely linked to the process of formation of binaries. We also explain the Binary period distribution as a result of stellar dynamical processes in star cluster environments. The agreement with the theory enforces the view that low-mass wide binaries may not be primordial but result from random stellar encounters.
Pavel Kroupa - One of the best experts on this subject based on the ideXlab platform.
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The origin of very wide Binary Stars
arXiv: Solar and Stellar Astrophysics, 2011Co-Authors: M. B. N. Kouwenhoven, Melvyn B. Davies, Pavel Kroupa, Simon P. Goodwin, Richard J. Parker, Daniel MalmbergAbstract:A large population of fragile, wide (> 1000 AU) Binary systems exists in the Galactic field and halo. These wide Binary Stars cannot be primordial because of the high stellar density in star forming regions, while formation by capture in the Galactic field is highly improbable. We propose that these Binary systems were formed during the dissolution phase of star clusters (see Kouwenhoven et al. 2010, for details). Stars escaping from a dissolving star cluster can have very similar velocities, which can lead to the formation of a wide Binary systems. We carry out N-body simulations to test this hypothesis. The results indicate that this mechanism explains the origin of wide Binary systems in the Galaxy. The resulting wide Binary fraction and semi-major axis distribution depend on the initial conditions of the dissolving star cluster, while the distributions in eccentricity and mass ratio are universal. Finally, since most Stars are formed in (relatively tight) primordial binaries, we predict that a large fraction of the wide "Binary Stars" are in fact higher-order multiple systems.
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Binary Stars in Praesepe
Monthly Notices of the Royal Astronomical Society, 1992Co-Authors: Pavel Kroupa, Christopher A. ToutAbstract:We consider the luminosity function and the distribution of Stars in the colour-magnitude diagram for Praesepe. The luminosity function is consistent with the solar neighbourhood function but is not sufficiently complete at faint magnitudes to constrain Binary system properties. The colour-magnitude data are consistent with a large Binary population. Systems with 1.0≥B−V≥0.8 seem to favour uncorrelated masses while bluer systems tend towards equal masses. Redder than B−V≃1.0, the data are not good enough to analyse the effects of Binary Stars
Sake J. Hogeveen - One of the best experts on this subject based on the ideXlab platform.
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Statistical properties of spectroscopic Binary Stars
Astrophysics and Space Science, 1992Co-Authors: Sake J. HogeveenAbstract:As part of a study of the mass-ratio distribution of spectroscopic Binary Stars, the statistical properties of the systems in theEighth Catalogue of the Orbital Elements of Spectroscopic Binary Stars, compiled by Battenet al. (1989), are investigated.
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The Mass-Ratio Distribution of Spectroscopic Binary Stars
Astrophysics and Space Science, 1992Co-Authors: Sake J. HogeveenAbstract:In order to determine the mass-ratio distribution of spectroscopic Binary Stars, the selection effects that govern the observations of this class of Binary systems are investigated. The selection effects are modelled numerically and analytically. The results of the models are compared to the data inThe Eighth Catalogue of the Orbital Elements of Spectroscopic Binary Stars (DAO8) compiled by Battenet al. (1989). The investigations involve Binary systems with Main-Sequence primary components only, in order to avoid confusion of evolutionary and selection effects.
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Determination of the mass-ratio distribution, II: double-lined spectroscopic Binary Stars
Astrophysics and Space Science, 1992Co-Authors: Sake J. HogeveenAbstract:The application of the Richardson-Lucy iterative technique for the rectification of measurement errors, to the mass-ratio distribution of the double-lined spectroscopic Binary Stars (SBII) in theSixth Catalogue of the Orbital Elements of Spectroscopic Binary Stars, is evaluated for the SBII systems in the Eighth version of the Catalogue.
Joel E. Tohline - One of the best experts on this subject based on the ideXlab platform.
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THE ORIGIN OF Binary Stars
Annual Review of Astronomy and Astrophysics, 2002Co-Authors: Joel E. TohlineAbstract:▪ Abstract Although we have a general understanding of the manner in which individual Stars form, our understanding of how Binary Stars form is far from complete. This is in large part due to the f...
Tal Alexander - One of the best experts on this subject based on the ideXlab platform.
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Beaming Binaries: A New Observational Category of Photometric Binary Stars
The Astrophysical Journal, 2007Co-Authors: Shay Zucker, Tsevi Mazeh, Tal AlexanderAbstract:The new photometric spaceborne survey missions COROT and Kepler will be able to detect minute flux variations in Binary Stars due to relativistic beaming caused by the line-of-sight motion of their components. In all but very short period binaries (P > 10 days), these variations will dominate over the ellipsoidal and reflection periodic variability. Thus, COROT and Kepler will discover a new observational class: photometric beaming Binary Stars. We examine this new category and the information that the photometric variations can provide. The variations that result from the observatory heliocentric velocity can be used to extract some spectral information even for single Stars.