The SLoWPoKES Catalog of Low-mass Ultra-wide Binaries: A Cool Stars Resource for Testing Fundamental Properties and for Constraining Binary Formation Theory

• Main Authors: Dhital, Saurav, West, Andrew A, Stassun, Keivan G, Law, Nicholas M
• Format: Journal Article
• Language: English
• Published: 11-09-2012
• Subjects: Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.1209.2206

We present results from the Sloan Low-mass Wide Pairs of Kinematically
Equivalent Stars (SLoWPoKES) catalog of ultra-wide (10^3-10^5.5 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 followup spectroscopic observations to recalibrate the
metallicity-sensitive {\zeta}_(TiO/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 SLoWPoKES catalog is publicly available on a custom
data visualization portal.