The properties of the central star of NGC 6543.

Abstract

The nucleus of NGC 6543 has been classified as a WR+Of star. From low dispersion ultraviolet spectra taken with the IUE, the authors determined its temperature (T = 80,000K) and luminosity (log L/L_sun; = 4.18). High solution spectra, also taken with the IUE, were used to study in detail the mass loss from the nucleus. The wind velocity was found to be 1900 km/s, and the mass loss rate dM/dt = 3.2×10^-7M_sun;/yr. The authors briefly discuss evolutionary aspects that might have led to the present nucleus and the surrounding nebula.