A SURVEY OF STELLAR FAMILIES: MULTIPLICITY OF SOLAR-TYPE STARS

By D. Raghavan, H. Mcalister, T. Henry, D. Latham, G. Marcy, B. Mason, D. Gies, Russel J. White, T. T. ten Brummelaar. 2009

1,471 citations recorded by the source corpus.

We present the results of a comprehensive assessment of companions to solar-type stars. A sample of 454 stars, including the Sun, was selected from the Hipparcos catalog with π>40 mas, σπ/π < 0.05, 0.5 ⩽ B − V ⩽ 1.0 (∼F6–K3), and constrained by absolute magnitude and color to exclude evolved stars. These criteria are equivalent to selecting all dwarf and subdwarf stars within 25 pc with V-band flux between 0.1 and 10 times that of the Sun, giving us a physical basis for the term “solar-type.” New observational aspects of this work include surveys for (1) very close companions with long-baseline interferometry at the Center for High Angular Resolution Astronomy Array, (2) close companions with speckle interferometry, and (3) wide proper-motion companions identified by blinking multi-epoch archival images. In addition, we include the results from extensive radial-velocity monitoring programs and evaluate companion information from various catalogs covering many different techniques. The results presented here include four new common proper-motion companions discovered by blinking archival images. Additionally, the spectroscopic data searched reveal five new stellar companions. Our synthesis of results from many methods and sources results in a thorough evaluation of stellar and brown dwarf companions to nearby Sun-like stars. The overall observed fractions of single, double, triple, and higher-order systems are 56% ± 2%, 33% ± 2%, 8% ± 1%, and 3% ± 1%, respectively, counting all confirmed stellar and brown dwarf companions. If all candidate, i.e., unconfirmed, companions identified are found to be real, the percentages would change to 54% ± 2%, 34% ± 2%, 9% ± 2%, and 3% ± 1%, respectively. Our completeness analysis indicates that only a few undiscovered companions remain in this well-studied sample, implying that the majority (54% ± 2%) of solar-type stars are single, in contrast to the results of prior multiplicity studies. Our sample is large enough to enable a check of the multiplicity dependence on various physical parameters by analyzing appropriate subsamples. Bluer, more massive stars are seen as more likely to have companions than redder, less massive ones, consistent with the trend seen over the entire spectral range. Systems with larger interaction cross sections, i.e., those with more than two components or long orbital periods, are preferentially younger, suggesting that companions may be stripped over time by dynamical interactions. We confirm the planet–metallicity correlation (i.e., higher metallicity stars are more likely to host planets), but are unable to check it for brown dwarfs due to the paucity of such companions, implying that the brown dwarf desert extends over all separation regimes. We find no correlation between stellar companions and metallicity for B − V < 0.625, but among the redder subset, metal-poor stars ([Fe/H] <−0.3) are more likely to have companions with a 2.4σ significance. The orbital-period distribution of companions is unimodal and roughly log normal with a peak and median of about 300 years. The period–eccentricity relation shows the expected circularization for periods below 12 days, caused by tidal forces over the age of the Galaxy, followed by a roughly flat distribution. The mass-ratio distribution shows a preference for like-mass pairs, which occur more frequently in relatively close pairs. The fraction of planet hosts among single, binary, and multiple systems are statistically indistinguishable, suggesting that planets are as likely to form around single stars as they are around components of binary or multiple systems with sufficiently wide separations. This, along with the preference of long orbital periods among stellar systems, increases the space around stars conducive for planet formation, and perhaps life.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/8d0c16b72a48d90786a4e1f09a2b7462765d260e

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Citations in the corpus

SOPHIE velocimetry of Kepler transit candidates XVII. The physical properties of giant exoplanets within 400 days of period (2015, background): “First, the circular orbit assumption is not reasonable for binaries with an orbital period longer than about 10 days (Halbwachs et al. 2003; Raghavan et al. 2010).”
HOW TO CONSTRAIN YOUR M DWARF: MEASURING EFFECTIVE TEMPERATURE, BOLOMETRIC LUMINOSITY, MASS, AND RADIUS (2015, methodology): “It has been estimated that 40% of M dwarfs in the solar neighborhood have at least one companion within 1000 AU (Fischer & Marcy 1992; Lada 2006; Raghavan et al. 2010).”
A STELLAR CENSUS OF THE TUCANA–HOROLOGIUM MOVING GROUP (2014, background): “Given a short-period binary frequency of F ∼ 10% for a < 2 AU (e.g., Raghavan et al. 2010), then our 142 members should be matched by ∼14 SBs that could have been rejected by their discrepant RVs, much as the 34 objects confirmed by Li include 5 RVdiscrepant objects that likely are SB1s.”
AN EFFICIENT AUTOMATED VALIDATION PROCEDURE FOR EXOPLANET TRANSIT CANDIDATES (2012, methodology): “There is no specific physical motivation for this procedure, but it reproduces well the observations of Raghavan et al. (2010), who observed roughly 35-40% of stars to be in binary systems and about 12% to be in triple or higher-order multiple systems, and a flat mass ratio distribution for binary…”
Timescales of Kozai-Lidov oscillations at quadrupole and octupole order in the test particle limit (2015, background): “Triple systems are common in the Galaxy, comprising ∼10% of systems in which the primary is ∼1 M⊙ (Duquennoy & Mayor 1991; Raghavan et al. 2010; Tokovinin 2014; Riddle et al. 2015).”
Individual Dynamical Masses of Ultracool Dwarfs (2017, methodology): “Compared to the extensive orbital information available for solar-type binaries spanning ≈6 orders of magnitude in period (e.g., Duquennoy & Mayor 1991; Raghavan et al. 2010), our visual binary sample covers a relatively narrow range of periods (.1 order of magnitude).”
THE IMPACT OF STELLAR MULTIPLICITY ON PLANETARY SYSTEMS. I. THE RUINOUS INFLUENCE OF CLOSE BINARY COMPANIONS (2016, methodology): “We used a log-flat prior on acut (matching the broadly logarithmic nature of the binary semimajor axis distribution; Raghavan et al. 2010) and a Beta prior on Sbin (since it is a binomial parameter; Jeffreys 1939).”
One of the closest exoplanet pairs to the 3:2 mean motion resonance: K2-19b and c (2015, methodology): “For the stellar multiplicity, we used the results from Raghavan et al. (2010) who reported an occurrence of binary star systems of 34% and an occurrence of triple systems of 9%.”
SECULAR EVOLUTION OF COMPACT BINARIES NEAR MASSIVE BLACK HOLES: GRAVITATIONAL WAVE SOURCES AND OTHER EXOTICA (2012, background): “The majority of stars reside in binary and higher multiplicity systems (Raghavan et al. 2010; Remage Evans 2011), and are observed to exist both in the field as well as in dense stellar environments such as globular clusters and galactic nuclei.”
Co-formation of the disc and the stellar halo (2018, methodology): “Assuming binary fractions of 0, 0.5 and 0.9 and a uniform mass ratio distribution (see Raghavan et al. 2010), we calculated the impact of the binaries on the measured tangential velocity dispersions.”
ACCELERATING COMPACT OBJECT MERGERS IN TRIPLE SYSTEMS WITH THE KOZAI RESONANCE: A MECHANISM FOR “PROMPT” TYPE Ia SUPERNOVAE, GAMMA-RAY BURSTS, AND OTHER EXOTICA (2010, background): “First, although only∼ 5− 10% of all solartype stars are thought to be in triple systems (Tokovinin et al. 2006; Raghavan et al. 2010), fully∼ 50% and∼ 100% of all close solar-type binaries with orbital periodP .”
THE ROLE OF MULTIPLICITY IN DISK EVOLUTION AND PLANET FORMATION (2011, background): “The binary frequency for separations of ∼4–40 AU is ∼20%, and an extrapolation 5 of the separation distribution seen for field binaries (Duquennoy & Mayor 1991; Raghavan et al. 2010) implies that there should be many more systems with separations of .3 AU.”
Searching for faint companions with VLTI/PIONIER - II. 92 main sequence stars from the Exozodi survey (2014, background): “A lot of papers were published regarding the multiplicity of solar-type stars (F-G stars), including e.g. censuses of binaries within 25 pc (Raghavan et al. 2010) and within 67 pc (Tokovinin 2014a,b).”
TWO WIDE PLANETARY-MASS COMPANIONS TO SOLAR-TYPE STARS IN UPPER SCORPIUS (2010, background): “This is now well known to be incorrect, with an approximately linearly flat distribution of companion masses for solar type primaries and ∼102AU separations (Kraus et al. 2008; Raghavan et al. 2010; Kraus et al 2010 in prep.).”
Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes (2017, background): “This is a sound assumption for massive stars of non-negligible metallicity (Raghavan et al. 2010; Chini et al. 2012; Moe & Di Stefano 2013, 2017).”
THE FALSE POSITIVE RATE OF KEPLER AND THE OCCURRENCE OF PLANETS (2013, methodology): “The frequency of stars in binaries and higher-multiplicity systems has been given by Raghavan et al. (2010) as Fbin = 44% (where we use the notation ‘bin’ to mean ‘nonsingle’).”
The Occurrence and Architecture of Exoplanetary Systems (2014, background): “Although the Sun has no stellar companion, a substantial fraction of Sun-like stars are part of multiple-star systems (Raghavan et al. 2010).”