Stellar radius response exponent
= Stellar radius response exponent
{title2=$\zeta=d\log R/d\log M$}
The stellar radius response exponent measures how a star's radius changes as it loses mass. The adiabatic exponent $\zeta_{\rm ad}$ describes loss too rapid for thermal adjustment; the equilibrium exponent $\zeta_{\rm eq}$ follows a sequence of thermally relaxed stars. Compare $\zeta_{\rm ad}$ with the <Roche-lobe radius response exponent> to test dynamical stability.