Radiation driven atmospheres of O-type stars: constraints on the mass–luminosity relation of central stars of planetary nebulae

Recent advances in the modelling of stellar winds driven by radiation pressure make it possible to fit many wind-sensitive features in the UV spectra of hot stars, opening the way for a hydrodynamically consistent determination of stellar radii, masses, and luminosities from the UV spectrum alone. It is thus no longer necessary to assume a theoretical mass–luminosity relation. As the method has been shown to work for massive O stars, we are now able to test predictions from the postAGB evolutionary calculations quantitatively for the first time. Here we present the first rather surprising consequences of using the new generation of model atmospheres for the analysis of a sample of central stars of planetary nebulae.