Are the orbital poles of binary stars in the solar neighbourhood anisotropically distributed?

Abstract

We test whether or not the orbital poles of the systems in the solar neighbourhood are isotropically distributed on the celestial sphere. The problem is plagued by the ambiguity on the position of the ascending node. Of the 95 systems closer than 18 pc from the Sun with an orbit in the 6th Catalogue of Orbits of Visual Binaries, the pole ambiguity could be resolved for 51 systems using radial velocity collected in the literature and CORAVEL database or acquired with the HERMES-Mercator spectrograph. For several systems, we can correct the erroneous nodes in the 6th Catalogue of Orbits and obtain new combined spectroscopic-astrometric orbits for seven systems [WDS 01083+5455Aa,Ab; 01418+4237AB; 02278+0426AB (SB2); 09006+4147AB (SB2); 16413+3136AB; 17121+4540AB; 18070+3034AB]. We used of spherical statistics to test for possible anisotropy. After ordering the binary systems by increasing distance from the Sun, we computed the false-alarm probability for subsamples of increasing sizes, from N = 1 up to the full sample of 51 systems. Rayleigh-Watson and Beran tests deliver a false-alarm probability of 0.5% for the 20 systems closer than 8.1 pc. To evaluate the robustness of this conclusion, we used a jackknife approach, for which we repeated this procedure after removing one system at a time from the full sample. The false-alarm probability was then found to vary between 1.5% and 0.1%, depending on which system is removed. The reality of the deviation from isotropy can thus not be assessed with certainty at this stage, because only so few systems are available, despite our efforts to increase the sample. However, when considering the full sample of 51 systems, the concentration of poles toward the Galactic position l = 46.0°, b = 37°, as observed in the 8.1 pc sphere, totally vanishes (the Rayleigh-Watson false-alarm probability then rises to 18%).

References in corpus (30)

• Validation of the new Hipparcos reduction
• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• Shrinking binary and planetary orbits by Kozai cycles with tidal friction
• Radial Velocities for 889 Late-type Stars
• SB9: The Ninth Catalogue of Spectroscopic Binary Orbits
• HERMES: a high-resolution fibre-fed spectrograph for the Mercator telescope
• Local kinematics of K and M giants from Coravel/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters
• Evolution in Binary and Triple Stars, with an application to SS Lac
• Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function
• The Distribution of Nearby Stars in Velocity Space Inferred from Hipparcos Data
• The Palomar/MSU Nearby Star Spectroscopic Survey III: Chromospheric Activity, M-dwarf Ages and the Local Star Formation History
• Predicting the Properties of Binary Stellar Systems: The Evolution of Accreting Protobinary Systems
• Comparative statistics and origin of triple and quadruple stars
• Constraining the difference in convective blueshift between the components of alpha Cen with precise radial velocities
• Radial Velocity Studies of Close Binary Stars.IV
• New neighbours. III. 21 new companions to nearby dwarfs, discovered with adaptive optics
• The Hyades stream: evaporated cluster or intrusion from the inner disk?
• On the age heterogeneity of the Pleiades, Hyades and Sirius moving groups
• Astrometric orbits of SB9 stars
• The PHASES Differential Astrometry Data Archive. V. Candidate Substellar Companions to Binary Systems
• High precision orbital and physical parameters of double-lined spectroscopic binary stars - HD78418, HD123999, HD160922, HD200077 and HD210027
• Chemically tagging the Hyades stream: Does it partly originate from the Hyades cluster?
• Masses, Luminosities, and Orbital Coplanarities of the mu Orionis Quadruple Star System from PHASES Differential Astrometry
• Analysis of 70 Ophiuchi AB including seismic constraints
• Precise Masses for Wolf 1062 AB from Hubble Space Telescope Interferometric Astrometry and McDonald Observatory Radial Velocities
• Precision Masses of the low-mass binary system GJ 623
• Establishing Alpha Oph as a Prototype Rotator: Improved Astrometric Orbit
• Studies of multiple stellar systems - IV. The triple-lined spectroscopic system Gliese 644
• Alignment of the Angular Momentum Vectors of Planetary Nebulae in the Galactic Bulge
• The PHASES Differential Astrometry Data Archive. III. Limits to Tertiary Companions

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