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Early-type Wolf-Rayet(WR) stellar models harbor a super-Eddington layer intheir outer envelopes due to a prominent iron opacity bump. In the past fewdecades, one-dimensional hydrostatic and time-steady hydrodynamic models havesuggested a variety of WR responses to a super-Eddington force includingenvelope inflation and optically thick winds. In this paper, I study theseresponses using semianalytical estimates and WR models from both MESA and Ro &Matzner; four conclusions are present. First, early-type WR stars do not harborinflated envelopes because they have either strong winds or insufficientluminosities. Second, the condition for an opacity bump to harbor a sonic pointis expressible as a minimum mass-loss rate, $\dot{M}_{\rm sp}(L_*)$. Inagreement with Grassitelli et al. and Ro, the majority of galactic early-typeWR stars can harbor sonic points at the iron opacity bump. However, about halfof those in the Large Magellanic Cloud cannot given typical wind parameters.Third, WR winds driven by the iron opacity bump must have mass-loss rates thatexceed a global minimum of $10^{-5.8}-10^{-6}M_\odot\,{\rm yr}^{-1}$. Lastly,the observed early-type WR distribution follows a simple mass-loss relationderived here if the radiation-to-gas pressure ratio is approximately $p_r/p_g\sim 145$ in the wind; a value consistent with studies by Grafener et al. andNakauchi & Saio.

The Wolf-Rayet Stellar Response To The Iron Opacity Bump: Envelope Inflation, Winds, and Microturbulence