Institution(s): 1. Beijing Normal University
The period-age-mass (P-t-M) relationship is a recently proposition for estimating the age of stars. From the knowledge and great quantities of observations, a relation among three fundamental stellar parameters, i.e. mass, age and rotation period, has been found in low-mass stars, which could potentially be a powerful tool to determine ages of stars when the other two parameters are given. To investigate stellar angular momentum evolution, we construct a grid of stellar models including diffusion and rotation-induced mixing. The calculation is carried out in given ranges of stellar mass with various initial rotation rates. Differential rotation (DR) model with the Kawaler Wind Law is adopted for early-K-, G- and F-stars (0.80 M⊙ ≤ M ≤ 1.60 M⊙), while solid body (SB) model with the new Wind Law is applied for mid- and early-F-stars (1.25 M⊙ < M ≤ 1.60 M⊙). By comparing our models with the observational data of four open clusters, we find that the DR model can reproduce the distributions of the periods of early-K-, G- and late-F-stars (0.80 M⊙ ≤ M < 1.25 M⊙). However, only the SB model leads to good fitting for mid- and early-F-stars. Furthermore, we obtain the surface in the three-dimensional space of mass, age, and stellar rotation period on which these stars lie. Our results suggest that ages estimated by P-t-M reltaion have the potential to be the most precise chronometer for early-K-, G- and F-stars.