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We intent to use stellar models with and without alpha-enhancement, as wellas asteroseismic analysis, to study two alpha-enhanced stars, KIC 7976303 andKIC 8694723. For the alpha-enhanced models, we adopt [alpha/Fe] = 0.2, and 0.4.For the evolved sub-giant KIC 7976303 with mixed-modes, alpha-enhanced modelsfit the observations better than the models without alpha-enhancement, andpoint to a star with M = 1.20 $\pm$ 0.02 M_odot, t = 4.88 $\pm$ 0.08 Gyr, R =2.04 $\pm$ 0.01 R_odot, and L = 5.07 $\pm$ 0.05 L_odot. For the post turnoffstar KIC 8694723, we find that the models fit the observations well in allthree cases ([alpha/Fe] = 0.0, 0.2, 0.4). According to the observed metalabundances, only alpha- enhanced models are used to estimate the stellarparameters, which are M = 1.13 $\pm$ 0.06 M_odot, t = 5.47 $\pm$ 0.43 Gyr, R =1.55 $\pm$ 0.13 R_odot, and L = 3.18 $\pm$ 0.26 L_odot. Our alpha-enhancedmodels indicate KIC 7976303 has a larger mass and younger age than in previousworks based on standard models. Furthermore, the differences of estimated massand age between the three cases are $\sim$ 0.1 M_odot and $\sim$ 0.5 - 1.3 Gyr.These results suggest that we include alpha-enhancement in the modeling ofalpha-enhanced stars, such as members of GCs (Globular Clusters), metal-poorstars in the disc and in the halo.

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