SLoWPoKES

Aptly coined by Andrew in deference of the extremely slow motions of low-mass, wide binary stars around each other, the SLoWPoKES project has the following aims:

To identify low-mass (mid-K to M spectral types), wide (s > 500 AU) pairs from the astrometric and photometric data of the Sloan Digital Sky Survey (SDSS).
Study the properties of wide, low-mass binaries, e.g. distribution of frequency, physical separation, and mass-ratios.
To exploit the coevality and similar evolutionary history - while being dynamically independent - of these pairs to empirically measure or constrain various properties of low-mass stars, especially the mass-age-activity-rotation relations.
To study the dynamical history and structure of the Milky Way using the disruption of wide, low-mass pairs
To identify a subset of wide, low-mass binaries that would be optimum for detection of gaseous and terrestrial planets in future astrometric missions like SIM-Lite.

Illustrated are gri composite images from SDSS for six systems identified in SLoWPoKES. The top three are examples of hierarchical triples while the last image is a probably hierarchical quadruple. We are using this sample to study a host of outstanding questions about low-mass stars, including activity lifetimes, stellar rotations, and frequency of hierarchical systems.

Paper I (Dhital, West, Stassun, & Bochanski 2009; in prep.) identifies 2675 pairs from the SDSS DR7 photometry (Abajazian et al. 2009) and the SDSS/USN0-B proper motions (Munn et al. 2004), already making SLoWPoKES one of the largest catalogs for wide binary systems. Candidates were identified based on a statistical matching of angular separation, photometric distances, and proper motion components and were vetted using a six-dimensional (3 positions & 3 velocities) Galactic Model. Rigorous and stringent selection criteria were adopted to keep the number of false positives to a minimum; all pairs were required to have (i) r-band magnitude <= 20, (ii) proper motion => 40 mas/yr, (iii) excellent quality photometry and proper motions, and (iv) probability of chance alignment <= 99%. This makes SLoWPoKES an ideal catalog for follow-up studies of low-mass star properties.

Paper II will expand the catalog with pairs identified without kinematic information.

People

Currently, Saurav Dhital (Vanderbilt), Andrew West (MIT), and Keivan Stassun (Vanderbilt) are the principal investigators for this project. In addition, to explore various science questions, we are collaborating with Sydney Barnes (Lowell), Cullen Blake (Harvard), John Bochanski (MIT), and Adam Kraus (Caltech), Nick Law (Caltech), Josh Pepper (Vanderbilt).

Publications

Paper I: Dhital, S., West A. A., Stassun, K. G., & Bochanski, J. J. 2009, in prep.
Sloan Low-Mass Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs
West, Dhital, Stassun, & Pepper, 2009, AAS 213, 455.10.
Expanding SIM Parameter Space with SLoWPoKES ADS poster (pdf)
Dhital, West, & Stassun 2009, Cool Stars XV,
SLoWPoKES: A Catalog of Very Wide, Low-Mass Binary Stars paper (pdf) poster (pdf)
Dhital, West, & Stassun 2008, AAS 211, 103.07
Search for Wide M Dwarf Binaries in the Sloan Digital Sky Survey ADS poster (pdf)

Public Data

Data will be released soon.