Submitting Campus

Daytona Beach

Department

Physical Sciences

Document Type

Article

Publication/Presentation Date

2-14-2011

Abstract/Description

We present the chromospheric activity (CA) levels, metallicities, and full space motions for 41 F, G, K, and M dwarf stars in 36 wide binary systems. Thirty-one of the binaries contain a white dwarf (WD) component. In such binaries, the total age can be estimated by adding the cooling age of the WD to an estimate of the progenitor’s main-sequence lifetime. To better understand how CA correlates to stellar age, 14 cluster member stars were also observed. Our observations demonstrate for the first time that, in general, CA decays with age from 50 Myr to at least 8 Gyr for stars with 1.0 < V − I < 2.4. However, little change occurs in the CA level for stars with V − I < 1.0 between 1 Gyr and 5 Gyr, consistent with the results of Pace et al. Our sample also exhibits a negative correlation between the stellar age and metallicity, a positive correlation between the stellar age and W space velocity component, and the W velocity dispersion increases with age. Finally, the population membership of these wide binaries is examined based upon their U, V, W kinematics, metallicity, and CA. We conclude that wide binaries are similar to field and cluster stars in these respects. More importantly, they span a much more continuous range in age and metallicity than is afforded by nearby clusters.

Publication Title

The Astronomical Journal

DOI

https://doi.org/10.1088/0004-6256/141/4/107

Publisher

IOP Publishing

Grant or Award Name

NSF grant AST-0807919, NSFC grant Nos. 10821061, 11073026, and 11078019

Additional Information

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

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