Stellar age and mass determinations from kinematic data

Assuming that some exchange of energy between stars in the galactic disk may be at work, I have generalized the formulae expressing the growth of the velocity variance with time by adding a mass term (M/M )^– with =0.35, which is a good fit to the kinematic data for young stars. The generalized formulae (5a) and (5b) and the evolutionary mass-age relation (Iben, 1967) were used jointly to derive mass and age values for different stellar species. The results, presented in Table IV, are followed by a discussion.