Long-term Spectroscopic Survey of the Pleiades Cluster: The Binary Population

Abstract

We present the results of a spectroscopic monitoring program of the Pleiades region aimed at completing the census of spectroscopic binaries in the cluster, extending it to longer periods than previously reachable. We gathered 6104 spectra of 377 stars between 1981 and 2021, and merged our radial velocities with 1151 measurements from an independent survey by others started three years earlier. With the combined data spanning more than 43 yr we have determined orbits for some 30 new binary and multiple systems, more than doubling the number previously known in the Pleiades. The longest period is 36.5 yr. A dozen additional objects display long-term trends in their velocities, implying even longer periods. We examine the collection of orbital elements for cluster members, and find that the shape of the incompleteness-corrected distribution of periods (up to $10^4$ days) is similar to that of solar-type binaries in the field, while that of the eccentricities is different. The mass-ratio distribution is consistent with being flat. The binary frequency in the Pleiades for periods up to $10^4$ days is $25\pm 3$%, after corrections for undetected binaries, which is nearly double that of the field up to the same period. The total binary frequency including known astrometric binaries is at least 57%. We estimate the internal radial velocity dispersion in the cluster to be $0.48\pm 0.04$ km s${}^{-1}$. We revisit the determination of the tidal circularization period, and confirm its value to be $7.2\pm 1.0$ days, with an improved precision compared to an earlier estimate.

40 pages in emulateapj format, including figures, tables, and appendix. Accepted for publication in The Astrophysical Journal

References in corpus (28)

• The Gaia mission
• Improving PARSEC models for very low mass stars
• The High Angular Resolution Multiplicity of Massive Stars
• The Radial Velocity Experiment (RAVE): Fifth Data Release
• Gaia Data Release 1: Catalogue validation
• High-Dispersion Optical Spectra of Nearby Stars Younger Than The Sun
• A VLBI Resolution of the Pleiades Distance Controversy
• Near and Mid-IR Photometry of the Pleiades, and a New List of Substellar Candidate Members
• Observational Evidence for Tidal Interaction in Close Binary Systems
• Close companions around young stars
• Variability Properties of 4 Million Sources in the $TESS$ Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey
• WIYN Open Cluster Study. LX. Spectroscopic Binary Orbits in NGC 6819
• The Seven Sisters DANCe. I. Empirical isochrones, Luminosity and Mass Functions of the Pleiades cluster
• A Multi-Membership Catalogue for 1876 Open Clusters using UCAC4 data
• Orbital Motion in Pre-Main Sequence Binaries
• Wide binaries are rare in open clusters
• Stellar Radial Velocities in the Old Open Cluster M67 (NGC 2682). II. The Spectroscopic Binary Population
• Variability in stellar granulation and convective blueshift with spectral type and magnetic activity. II. From young to old main-sequence K-G-F stars
• The Distribution of Stellar Mass in the Pleiades
• New BVIc Photometry of Low-mass Pleiades Stars: Exploring the Effects of Rotation on Broadband Colors
• A revised moving cluster distance to the Pleiades open cluster
• On the Motion of Stars in the Pleiades according to Gaia DR2 Data
• Study of the mass-ratio distribution of spectroscopic binaries. I. A novel algorithm
• Spectroscopic monitoring of rapidly-rotating early-type stars in the Pleiades cluster
• Robo-AO Discovery and Basic Characterization of Wide Multiple Star Systems in the Pleiades, Praesepe, and NGC 2264 Clusters
• Dynamical masses for the Pleiades binary system HII-2147
• A method to deconvolve mass ratio distribution from binary stars
• A Substellar Companion to Pleiades HII 3441

Cited by in corpus (19)

• Gaia Data Release 3: Catalogue Validation
• Revisiting the mass of open clusters with \emph{Gaia} data
• The multiplicity fraction in 202 open clusters from Gaia
• TESS observations of the Pleiades cluster: a nursery for delta Scuti stars
• Features of Gaia DR3 Spectroscopic Binaries I. Tidal circularization of Main-Sequence Stars
• Spectroscopic Orbits of Subsystems in Multiple Stars. X (Summary)
• Photometric Determination of Unresolved Main-sequence Binaries in the Pleiades: Binary Fraction and Mass Ratio Distribution
• The cosmic waltz of Coma Berenices and Latyshev 2 (Group X). Membership, phase-space structure, mass, and energy distributions
• LAMOST medium-resolution observations of the Pleiades
• $\delta$ Scuti pulsations in the bright Pleiades eclipsing binary HD 23642
• The Radcliffe Wave as traced by young open clusters: Stellar parameters, activity indicators, and abundances of solar-type members of eight young clusters
• An ALMA 1.3 millimeter Search for Debris Disks around Solar-type Stars in the Pleiades
• Orbital Modeling of HII 1348B: An Eccentric Young Substellar Companion in the Pleiades
• Resolving Pleiades binary stars with Gaia and speckle interferometric observations
• Polarization position angle standard stars: a reassessment of $\theta$ and its variability for seventeen stars based on a decade of observations
• Tidal Synchronization of Binaries in Pleiades
• Stellar masses and mass ratios for Gaia open cluster members
• Photometric Identification of Unresolved Binary Stars in Nearby Open Star Clusters
• Are there really some eccentric eclipsing binaries having orbital periods below 1 d?