The SLoWPoKES catalog of low-mass ultra–wide binaries: A cool stars resource for testing fundamental properties and for constraining binary formation theory

Authors

  • S. Dhital,

    Corresponding author
    1. Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, USA
    2. Department of Physics & Astronomy, Vanderbilt University, 6301 Stevenson Center, Nashville, TN, 37235, USA
    • Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, USA
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  • A.A. West,

    1. Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, USA
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  • K.G. Stassun,

    1. Department of Physics & Astronomy, Vanderbilt University, 6301 Stevenson Center, Nashville, TN, 37235, USA
    2. Department of Physics, Fisk University, 1000 17th Avenue N., Nashville, TN 37208, USA
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  • N.M. Law

    1. Dunlap Institute, University of Toronto, 50 St. George St, Toronto, ON, Canada
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Abstract

We present results from the Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES) catalog of ultra-wide (103–105.5 AU), low-mass (K5–M7) common proper motion binaries. We constructed a Galactic model, based on empirical stellar number density and 3D velocity distributions, to select bona fide pairs with probability of chance alignment <5 %, making SLoWPoKES an efficient sample for followup observations. Our initial catalog contains 1342 disk dwarf, subdwarf, and white dwarf-red dwarf systems and is the largest collection of low-mass, wide binaries ever assembled. The diversity – in mass, metallicity, age, and evolutionary states – of SLoWPoKES pairs makes it a valuable resource of coeval laboratories to examine and constrain the physical properties of low-mass stars. SLoWPoKES pairs show signatures of two (or more) formation modes in the distribution of the physical separation and higher-order multiplicity. Neither dynamical dissipation of primordial triples/quadruples or dynamical capture of ejected stars can explain the observed populations by itself. We use follow-up spectroscopic observations to recalibrate the metallicity-sensitive ζTiO/CaH index by assuming that both members of the binary system have the same composition. Our new formulation is a significantly better tracer of absolute metallicity, particularly for the early-type M dwarfs. The catalogs are publicly available on a custom data visualization portal. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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