Common Proper Motion Companions to Nearby Stars: Ages and Evolution
arXiv:0808.3414 · doi:10.1086/591638
Abstract
A set of 41 nearby stars (closer than 25 pc) is investigated which have very wide binary and common proper motion (CPM) companions at projected separations between 1000 and AU. These companions are identified by astrometric positions and proper motions from the NOMAD catalog. Based mainly on measures of chromospheric and X-ray activity, age estimation is obtained for most of 85 identified companions. Color -- absolute magnitude diagrams are constructed to test if CPM companions are physically related to the primary nearby stars and have the same age. Our carefully selected sample includes three remote white dwarf companions to main sequence stars and two systems (55 Cnc and GJ 777A) of multiple planets and distant stellar companions. Ten new CPM companions, including three of extreme separations, are found. Multiple hierarchical systems are abundant; more than 25% of CPM components are spectroscopic or astrometric binaries or multiples themselves. Two new astrometric binaries are discovered among nearby CPM companions, GJ 264 and HIP 59000 and preliminary orbital solutions are presented. The Hyades kinematic group (or stream) is presented broadly in the sample, but we find few possible thick disk objects and none halo stars. It follows from our investigation that moderately young (age Gyr) thin disk dwarfs are the dominating species in the near CPM systems, in general agreement with the premises of the dynamical survival paradigm. Some of the multiple stellar systems with remote CPM companions probably undergo the dynamical evolution on non-coplanar orbits, known as the Kozai cycle.
Accepted in ApJ
References in corpus (11)
- Constraining the Age-Activity Relation for Cool Stars: The SDSS DR5 Low-Mass Star Spectroscopic Sample
- Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
- Tertiary companions to close spectroscopic binaries
- Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems
- The minimum mass for star formation, and the origin of binary brown dwarfs
- New Distant Companions to Known Nearby Stars. II. Faint companions of Hipparcos stars and the frequency of wide binary systems
- Using the Galactic Dynamics of M7 Dwarfs to Infer the Evolution of Their Magnetic Activity
- Ca II H and K Chromospheric Emission Lines in Late K and M Dwarfs
- Rotation and activity of pre-main-sequence stars
- A Search for Planets Transiting the M Dwarf Debris Disk Host, AU Microscopii
- The nearby young visual binary HIP 115147 and its common proper motion companion LSPM J2322+7847
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