Schönberg–Chandrasekhar limit

In stellar astrophysics, the Schönberg–Chandrasekhar limit is the maximum mass of a non-fusing, isothermal core that can support an enclosing envelope. It is expressed as the ratio of the core mass to the total mass of the core and envelope.

Source: Wikipedia — Schönberg–Chandrasekhar limit (CC BY-SA 4.0)