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Description
Selecting the best quality data, I find that nearly all 0.5 to 1.2M_{sun}_ main sequence stars converge to a single rotational mass dependent sequence after 750Myr; when the mass is larger than 0.8M_{sun}_, most of them converge in ~120Myr. If stars rotate as rigid bodies, the angular momentum of the vast majority is within clearly outlined bounds. The lower boundary defines a terminal main sequence rotational isochrone, the upper one coincides with slow rotators from the Pleiades and stars from Praesepe delineate a third one. Mass dependent exponential relationships between angular momentum and age are determined from these isochrones. Age estimates based on the angular momentum, are acceptable in middle aged stars older than 750Myr and more massive than 0.6-0.7M_{sun}_. The evolution of the Rossby number indicates that the Parker dynamo may cease early on in stars where M/M_{sun}_>=1.1. An empirical formula for the torque, an idealized model for it and a relation between rotational period and magnetic field, lead to a formula for the evolution of the mass loss rate, predicting that the present solar rate is close to a minimum and that it was around five times more vigorous when life on Earth started.
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