Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics

  title={Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics},
  author={Eric E. Mamajek and L. A. Hillenbrand},
  journal={The Astrophysical Journal},
While the strong anticorrelation between chromospheric activity and age has led to the common use of the Ca II H and K emission index (R'_(HK) = L_(HK)/L_(bol)) as an empirical age estimator for solar-type dwarfs, existing activity-age relations produce implausible ages at both high and low activity levels.We have compiled R'_(HK) HK data from the literature for young stellar clusters, richly populating for the first time the young end of the activity-age relation. Combining the cluster… 
Calibration of the Hα Age–Activity Relation for M Dwarfs
In this work, we calibrate the relationship between Hα emission and M dwarf ages. We compile a sample of 892 M dwarfs with Hα equivalent width (Hα EW) measurements from the literature that are either
How accurately can we age-date solar-type dwarfs using activity/rotation diagnostics?
  • E. Mamajek
  • Physics
    Proceedings of the International Astronomical Union
  • 2008
Abstract It is well established that activity and rotation diminishes during the life of sun-like main sequence (~F7-K2V) stars. Indeed, the evolution of rotation and activity among these stars
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We present a spectroscopic analysis of over 38,000 low-mass stars from the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5). Analysis of this unprecedentedly large sample confirms the previously
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A Survey of Chromospheric Activity in the Solar-Type Stars in the Open Cluster M67*
We present the results of a spectroscopic survey of the Ca II H and K core strengths in a sample of 60 solar-type stars that are members of the solar-age and solar-metallicity open cluster M67. We
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The Hyades constitute a homogeneous sample of stars ideal for investigating the dependence of planet formation on the mass of the central star. Because of their youth, Hyades members are much more
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The available spectral type and color data for late-type Pleiades members have been reanalyzed, and new reddening estimates are obtained. New photometry for a small number of stars and a compilation
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Utilizing Hipparcos parallaxes, original radial velocities and recent literature values, new Ca ii H and K emission measurements, literature-based abundance estimates, and updated photometry
Ages for illustrative field stars using gyrochronology: viability, limitations and errors
We here develop an improved way of using a rotating star as a clock, set it using the Sun, and demonstrate that it keeps time well. This technique, called gyrochronology, derives ages for low-mass
The Evolution of X-Ray Emission in Young Stars
The evolution of magnetic activity in late-type stars is part of the intertwined rotation-age-activity relation which provides an empirical foundation to the theory of magnetic dynamos. We study the