ABSTRACT
The advantage of this equation is that when we use the adiabatic equation of state it becomes an equation for one variable only, p. This treatment is historically important because Emden obtained the first concepts of stellar structure in this way in 1907. But its importance is not solely historical. Even today, when we want to get a first approximation of a stellar model, this method will yield reasonable results by the use of a suitable adiabatic exponent or of multizone models with different adiabatic exponents for each zone.
