What feature characterizes the Sedov-Taylor phase of evolution?

Answer

The growth of instabilities, specifically Rayleigh-Taylor instabilities

The Sedov-Taylor phase is marked by the slowing expansion rate as swept-up mass nears ejecta mass, facilitating the growth of Rayleigh-Taylor instabilities that mix the shocked interstellar material with the original stellar debris.

What feature characterizes the Sedov-Taylor phase of evolution?
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