  We study the dynamics of a homogeneous granular gas heated by a stochastic
thermostat, in the low density limit. It is found that, before reaching the
stationary regime, the system quickly "forgets" the initial condition and then
evolves through a universal state that does not only depend on the
dimensionless velocity, but also on the instantaneous temperature, suitably
renormalized by its steady state value. We find excellent agreement between the
theoretical predictions at Boltzmann equation level for the one-particle
distribution function, and Direct Monte Carlo simulations. We conclude that at
variance with the homogeneous cooling phenomenology, the velocity statistics
should not be envisioned as a single-parameter, but as a two-parameter scaling
form, keeping track of the distance to stationarity.
