Age-Related Observations of Low Mass Pre-Main and Young Main Sequence Stars (Invited Review)

Abstract

This overview summarizes the age dating methods available for young sub-solar mass stars. Pre-main sequence age diagnostics include the Hertzsprung-Russell (HR) diagram, spectroscopic surface gravity indicators, and lithium depletion; asteroseismology is also showing recent promise. Near and beyond the zero-age main sequence, rotation period or vsini and activity (coronal and chromospheric) diagnostics along with lithium depletion serve as age proxies. Other authors in this volume present more detail in each of the aforementioned areas. Herein, I focus on pre-main sequence HR diagrams and address the questions: Do empirical young cluster isochrones match theoretical isochrones? Do isochrones predict stellar ages consistent with those derived via other independent techniques? Do the observed apparent luminosity spreads at constant effective temperature correspond to true age spreads? While definitive answers to these questions are not provided, some methods of progression are outlined.

to appear in IAU Symposium 258, "Ages of Stars", E.E. Mamajek, D.R. Soderblom, R.F.G. Wyse, eds

References in corpus (13)

• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• The Y^2 Stellar Evolutionary Tracks
• A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages
• Astrophysics of Young Star Binaries
• Lithium Depletion of Nearby Young Stellar Associations
• A Large-Area Search for Low Mass Objects in Upper Scorpius I: The Photometric Campaign and New Brown Dwarfs
• A Large-Area Search for Low-Mass Objects in Upper Scorpius II: Age and Mass Distributions
• Age spreads in star forming regions: The lithium test in the Orion Nebula Cluster
• Lithium Depletion Boundary in a Pre-Main Sequence Binary System
• A Long-Lived Accretion Disk Around a Lithium-Depleted Binary T Tauri Star
• Can variability account for apparent age spreads in OB association colour-magnitude diagrams?
• Comparing the observational instability regions for pulsating pre-main sequence and classical $\delta$ Scuti stars
• What are the temperatures of T Tauri stars? - Constraints from coeval formation of young eclipsing binaries

Cited by in corpus (3)

• A Universal Stellar Initial Mass Function? A Critical Look at Variations
• From Birth to Death of Protoplanetary Disks: Modeling Their Formation, Evolution, and Dispersal
• Using a neural network approach and starspots dependent models to predict effective temperatures and ages of young stars