We extend the scaling relations of stably stratified turbulence from geophysical regime unity Prandtl number to astrophysical extremely small applicable regions stars and gas giants. A transition a new turbulent is found occur when drops below inverse buoyancy Reynolds number, i.e. $PrRb<1$, which signals shift dominant balance in equation. Application critical arguments then derives prediction...

(abridged) Context: The ratio of kinematic viscosity to thermal diffusivity, the Prandtl number, is much smaller than unity in stellar convection zones. Aims: To study statistics convective flows and energy transport as functions number. Methods: Three-dimensional numerical simulations Cartesian geometry are used. zone (CZ) embedded between two stably stratified layers. Statistics properties up...