The spindown of solar-type stars

Rotation periods of G-type stars as a function of their age, all data from the literature. Blue symbols: G-type field stars from the Mt. Wilson survey, as listed in Barnes (2007), size of the symbol scaled with spectral type (G9 smallest size, G0 largest size). Green symbol: Sun (spectral type G2). Red symbol: Average value for G2 stars in the Hyades (Radick et al. 1987). Overplotted is the empirical 'Skumanich law' (Skumanich 1972) - rotation period proportional to the squareroot of age - scaled to match the solar value.