http://arxiv.org/abs/1503.06690
We provide a status report on the determination of stellar ages from asteroseismology for stars of various masses and evolutionary stages. The ability to deduce the ages of stars with a relative precision of typically 10 to 20% is a unique opportunity for stellar evolution and also of great value for both galactic and exoplanet studies. Further, a major uncalibrated ingredient that makes stellar evolution models uncertain, is the stellar interior rotation frequency $\Omega(r)$ and its evolution during stellar life. We summarize the recent achievements in the derivation of $\Omega(r)$ for different types stars, offering stringent observational constraints on theoretical models. Core-to-envelope rotation rates during the red giant stage are far lower than theoretical predictions, pointing towards the need to include new physical ingredients that allow strong and efficient coupling between the core and the envelope in the models of low-mass stars in the evolutionary phase prior to the core helium burning. Stars are subject to efficient mixing phenomena, even at low rotation rates. Young massive stars with seismically determined interior rotation frequency reveal low core-to-envelope rotation values.
C. Aerts
Tue, 24 Mar 15
2/60
Comments: 10 pages, 5 figures, to appear in Astronomische Nachrichten/Astronomical Notes
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