In this article we present some results in existence and uniqueness of strong and classical solutions of the hydrodynamic equations modeling solar and stellar winds. The system of Navier-Stokes equations for solar and stellar winds is considered in its corresponding differential evolution equation form (d/dt+A)υ(t) = F(υ(t), t), where F is a given non-linear function and-A is the infinitesimal generator of the analytic semigroup arising from the hydrodynamic Stokes operator.