Synestia

[1] In computer simulations of giant impacts of rotating objects, a synestia can form if the total angular momentum is greater than the co-rotational limit.

[3] In the case of a synestia, the result is an inner region rotating at a single rate with a loosely connected torus orbiting beyond it.

[4] Synestias also have differences in the mantles, both thermally and in their composition, from previous terrestrial evolution models due partially to a lower interior pressure.

The temperature gradient is created by the mixture of hot vapor from the inner regions with colder condensed material from farther out.

This transitions into the disk-like region whose appearance can vary dramatically with different initial conditions for angular momentum, mass, and entropy.