1. The problem statement, all variables and given/known data The problem reads: In the core a low mass red giant the free electrons are completely degenerate. Suppose that the mass of the core is 0.5 * M_sun (Mass of the sun). Assume that the core can be described by a polytrope and calculate its radius using the mass-radius relationship. 2. Relevant equations 3. The attempt at a solution So I'm aware of the mass-radius relation found from the Lane-Emden equation, but I am not sure what value for index, n, I should use for the core of a low mass red giant--specifically one that has free electrons that are completely degenerate.