Astronomy and Astrophysics – Astrophysics
Scientific paper
Dec 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009a%26a...508..849g&link_type=abstract
Astronomy and Astrophysics, Volume 508, Issue 2, 2009, pp.849-854
Astronomy and Astrophysics
Astrophysics
4
Stars: Evolution, Stars: Interiors, Stars: Oscillations
Scientific paper
Aims. Element diffusion is a basic physical element transport mechanism which induces the redistribution of chemical elements. Using the asteroseismic method, we study the effects of helium and heavy element diffusion on the internal structure and stellar evolution of solar-type stars. We also provide asteroseismic parameters for a grid of models which would be useful for direct comparison with the Kepler mission observations. Methods: We construct a grid of solar-type stellar models with various masses (from 0.8 M&sun; to 1.2 M&sun;) and metallicities (Zi = 0.03, 0.025, 0.02, 0.015, 0.01, 0.005) with and without helium and heavy element diffusion. We compute “second differences” and “small separations” of the solar-metallicity models (Zi = 0.02) to analyze the effects of diffusion on the convection zone, helium abundance and the evolutionary sequence of the star. In order to study the asteroseismic property of models with and without diffusion, we compute the p-mode oscillation frequencies of low-degree modes for a grid of models and construct the (< Δν0 >, < d02 >) asteroseismic diagram. Results: We find that the element diffusion could speed up the evolution of the star, especially in the main sequence. The results show that it could enlarge the convective core and change the base of the convection envelope. In addition, the helium and heavy element diffusion make the models evolve to lower large and small separations in the asteroseismic diagram. This effect is more efficient at lower metallicity.
Tables [see full textsee full textsee full textsee full textsee full text]-[see full textsee full textsee full textsee full textsee full text] are only available in electronic form at http://www.aanda.org
Bi Shao-Lan
Gai Ning
Li Ling-Huai
Tang Yan-Ke
No associations
LandOfFree
Asteroseismic study of helium and heavy element diffusion in solar-type stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Asteroseismic study of helium and heavy element diffusion in solar-type stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Asteroseismic study of helium and heavy element diffusion in solar-type stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1764889