Revisiting Wolf-Rayet Masses Through the Photogravitational Parameter Φ

This work introduces a surface-anchored mass diagnostic for Wolf-Rayet (WR) stars using the photogravitational parameter Φ = L/(Mg), which combines bolometric luminosity, mass, and surface gravity into a single observable. We calibrate subtype-dependent scale factors on 12 WR+O binaries with dynamical masses, achieving 9% RMS accuracy via leave-one-out cross-validation. Applied to 10 isolated WR stars with internally consistent atmospheric parameters, the method yields photogravitational masses 42% below evolutionary track predictions (median), with 25-35% uncertainties from Monte Carlo error propagation (N=10⁴). The systematic offset suggests enhanced mass loss near the Eddington limit, envelope inflation, and/or binary interaction histories among apparently single WR stars. The framework provides a falsifiable, observation-based mass scale for ~60 Galactic WR objects lacking dynamical constraints, with direct implications for supernova progenitor masses and gravitational wave source populations.