Far-UV Temperature Diagnostics for Hot Central Stars of Planetary Nebulae

We report on an analysis and modeling of the FUSE spectrum of HD 200516, the central star of NGC 7009, and find strong evidence that the effective temperature is close to 95,000K. This is significantly hotter than the 82,000K found from the analysis of optical He II lines. This determination used the numerous lines of highly ionized abundant elements (O, Fe, Ni) that are located in the far-UV spectrum of hot post-AGB stars. There is also evidence that the fluorine abundance in HD 200S16 may be significantly enhanced.