Constraining the evolution of stellar rotation using solar twins

Abstract

The stellar rotation versus age relation is commonly considered a useful tool to derive reliable ages for Sun-like stars. However, in the light of Kepler data, the presence of apparently old and fast rotators that do not obey the usual gyrochronology relations led to the hypothesis of weakened magnetic breaking in some stars. In this letter, we constrain the solar rotation evolutionary track using solar twins. Predicted rotational periods as a function of mass, age, [Fe/H], and given critical Rossby number (Rocrit) were estimated for the entire rotational sample. Our analysis favours the smooth rotational evolution scenario and suggests that if the magnetic weakened breaking scenario takes place at all, it should arise after Rocrit ≳ 2.29 or ages ≳5.3 Gyr (at 95 per cent confidence level). Show more