The bright , nearby binary \alpha Centauri provides an excellent laboratory for testing stellar evolution models , as it is one of the few stellar systems for which we have high-precision classical ( mass , radius , luminosity ) and asteroseismic ( p -mode ) observations .
Stellar models are created and fit to the classical and seismic observations of both stars by allowing for the free variation of convective mixing length parameter \alpha _ { \text { MLT } } .
This system is modeled using five different sets of assumptions about the physics governing the stellar models .
There are 31 pairs of tracks ( out of { \sim } 150 , 000 generated ) which fit the classical , binary , and seismic observational constraints of the system within 3 \sigma .
Models with each tested choice of input physics are found to be viable , but the optimal mixing lengths for \alpha Cen A and \alpha Cen B remain the same regardless of the physical prescription .
The optimal mixing lengths are \alpha _ { \text { MLT,A } } / \alpha _ { \odot } = 0.932 and \alpha _ { \text { MLT,B } } / \alpha _ { \odot } = 1.095 .
That \alpha Cen A and \alpha Cen B require sub- and super-solar mixing lengths , respectively , to fit the observations is a trend consistent with recent findings , such as in , , and .
The optimal models find an age for \alpha Centauri of 5.3 \pm 0.3 Gyr .