Submitting Campus

Daytona Beach


Physical Sciences

Document Type


Publication/Presentation Date



We investigate the relationship between age and chromospheric activity for 139 M dwarf stars in wide binary systems with white dwarf companions. The age of each system is determined from the cooling age of its white dwarf component. The current limit for activity-age relations found for M dwarfs in open clusters is 4 Gyr. Our unique approach to finding ages for M stars allows for the exploration of this relationship at ages older than 4 Gyr. The general trend of stars remaining active for a longer time at later spectral type is confirmed. However, our larger sample and greater age range reveals additional complexity in assigning age based on activity alone. We find that M dwarfs in wide binaries older than 4 Gyr depart from the log-linear relation for clusters and are found to have activity at magnitudes, colors and masses which are brighter, bluer and more massive than predicted by the cluster relation. In addition to our activity-age results, we present the measured radial velocities and complete space motions for 161 white dwarf stars in wide binaries.

Publication Title

The Astronomical journal



The Institute of Physics

Grant or Award Name

NASA Graduate Researchers Program Grant NGT 200415, NFS AST02-05875, NASA Grant Y701296, NSF Grant AST 0206115

Additional Information

Dr. Oswalt was not affiliated with Embry-Riddle Aeronautical University at the time this paper was published.