Zhishuai Ge

LITHIUM ABUNDANCE AS A PREDICTOR OF MASS AND AGE IN SOLAR-ANALOG STARS

In order to estimate the mass and age of stars, we construct a grid of stellar models for eight solar-analog stars including diffusion and rotation-induced mixing for the given ranges of stellar mass, metallicity, and rotational rate. By combining stellar models with observational data including lithium abundance, we obtain more accurate estimations of mass and age for solar-analog stars. The results indicate that stars HIP 56948, HIP 73815, and HIP 78399 are three possible solar twins. Furthermore, we find that lithium depletion due to extra-mixing in solar analogs strongly depends on mass, metallicity, and rotational history. Therefore, lithium abundance can be used as a good constraint in stellar modeling.

ASTEROSEISMIC ANALYSIS OF THE CoRoT TARGET HD 49933

The satellite CoRoT (Convection, Rotation, and planetary Transits) has provided high-quality data for almost six years. We show here the asteroseismic analysis and modeling of HD169392A, which belongs to a binary system weakly gravitationally bound as the distance between the two components is of 4250 AU. The main component, HD169392A, is a G0IV star with a magnitude of 7.50 while the second component is a G0V-G2IV star with a magnitude of 8.98. This analysis focuses on the main component, as the secondary one is too faint to measure any seismic parameters. A complete modeling has been possible thanks to the complementary spectroscopic observations from HARPS, providing Teff=5985+/-60K, log g=3.96+/-0.07, and [Fe/H]=- 0.04+/-0.10.

Asteroseismic analysis of Kepler target KIC 2837475

The ratios

EFFECTS OF MAGNETIC FIELDS ON LITHIUM EVOLUTION IN F AND G STARS

r_{01}

Mass and age of red giant branch stars observed with LAMOST and Kepler

and

Stellar parameters of main sequence turn-off star candidates observed with LAMOST and Kepler

r_{10}

Asteroseismic analysis of two α-enhanced stars KIC 7976303 and KIC 8694723

of small to large separations of KIC 2837475 primarily exhibit an increase behavior in the observed frequency range. The calculations indicate that only the models with overshooting parameter

Precise determination of fundamental parameters of six exoplanet host stars and their planets

\delta_{\rm ov}

Ages of 70 dwarfs of three populations in the solar neighborhood: considering O and C abundances in stellar models

between approximately 1.2 and 1.6 can reproduce the observed ratios

Exploring the sources of p-mode frequency shifts in the CoRoT target HD 49933

r_{01}