The Metallicity of Stars with Close Companions

Abstract

We examine the relationship between the frequency of close companions (stellar and planetary companions with orbital periods < 5 years) and the metallicity of their Sun-like (~ FGK) hosts. We confirm and quantify a ~4 sigma positive correlation between host metallicity and planetary companions. We find little or no dependence on spectral type or distance in this correlation. In contrast to the metallicity dependence of planetary companions, stellar companions tend to be more abundant around low metallicity hosts. At the ~2 sigma level we find an anti-correlation between host metallicity and the presence of a stellar companion. Upon dividing our sample into FG and K sub-samples, we find a negligible anti-correlation in the FG sub-sample and a 3 sigma anti-correlation in the K sub-sample. A kinematic analysis suggests that this anti-correlation is produced by a combination of low-metallicity, high-binarity thick disk stars and higher-metallicity, lower-binarity thin disk stars.

arXiv commentConforms to version accepted by ApJ. 15 pages formatted with emulateapj.cls

References in corpus (18)

• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation
• Elemental Abundance Survey of The Galactic Thick Disk
• Kinematics of Metal-Poor Stars in the Galaxy. III. Formation of the Stellar Halo and Thick Disk as Revealed from a Large Sample of Non-Kinematically Selected Stars
• How Dry is the Brown Dwarf Desert?: Quantifying the Relative Number of Planets, Brown Dwarfs and Stellar Companions around Nearby Sun-like Stars
• Parent Stars of Extrasolar Planets VI: Abundance Analyses of 20 New Systems
• Catalogue of [Fe/H] determinations for FGK stars : 2001 edition
• Spectroscopic metallicities for planet-host stars: extending the samples
• The N2K Consortium. IV. New temperatures and metallicities for 100,000+ FGK dwarfs
• Parent Stars of Extrasolar Planets VII: New Abundance Analyses of 30 Systems
• High eccentricity planets from the Anglo-Australian Planet Search
• On the Nature of Stars with Planets
• Extra-solar planets around HD196050, HD216437 and HD160691
• What Fraction of Sun-like Stars have Planets?
• Binarity, activity and metallicity among late-type stars I. Methodology and application to HD 27536 and HD 216803
• A Survey of Proper Motion Stars. XVII. A Deficiency of Binary Stars on Retrograde Galactic Orbits and the Possibility that omega Centauri is Related to the Effect
• Luminosity-metallicity relation for stars on the lower main sequence
• Stellar Activity and the Stromgren Photometric Metallicity Calibration of Intermediate-Type Dwarf Stars

Cited by in corpus (27)

• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• The Occurrence and Architecture of Exoplanetary Systems
• The Close Binary Fraction of Solar-type Stars is Strongly Anti-correlated with Metallicity
• The statistical properties of stars and their dependence on metallicity
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• A Model of Habitability Within the Milky Way Galaxy
• The Close Binary Fraction as a Function of Stellar Parameters in APOGEE: A Strong Anti-Correlation With $\alpha$ Abundances
• Stellar loci II. a model-free estimate of the binary fraction for field FGK stars
• The SOPHIE search for northern extrasolar planets. IV. Massive companions in the planet-brown dwarf boundary
• Robo-AO Kepler Survey V: The effect of physically associated stellar companions on planetary systems
• Lifetime of short-period binaries measured from their Galactic kinematics
• Emission lines in the atmosphere of the irradiated brown dwarf WD0137-349B
• The non-monotonic, strong metallicity dependence of the wide-binary fraction
• Multiplicity and period distribution of Population II field stars in solar vicinity
• A comprehensive comparison of the Sun to other stars: searching for self-selection effects
• Cool Subdwarf Investigations II: Multiplicity
• The Gaia-ESO Survey: detection and characterization of single line spectroscopic binaries
• Signs of accretion in the white dwarf + brown dwarf binary NLTT5306
• Two New Long-Period Hot Subdwarf Binaries with Dwarf Companions
• Multiplicity of the Galactic Senior Citizens: A high-resolution search for cool subdwarf companions
• The statistical properties of stars at redshift, z=5, compared with the present epoch
• The Cosmological Constant in the Quantum Multiverse
• Binary Contamination in the SEGUE sample: Effects on SSPP Determinations of Stellar Atmospheric Parameters
• ExELS: an exoplanet legacy science proposal for the ESA Euclid mission. II. Hot exoplanets and sub-stellar systems
• Evolutionary Constraints on the Long-period Subdwarf B Binary PG 1018-047
• Not that simple: the metallicity dependence of the wide binary fraction changes with separation and stellar mass
• Stellar masses and mass ratios for Gaia open cluster members