Far ultraviolet emission from NGC 7009

The high-excitation planetary nebula NGC 7009 and its central star were observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) through a 30 $\,{\times}\,$ 30 arcsec (LWRS) aperture, and with the HIRS narrow slit (1.25 $\,{\times}\,$ 20 arcsec) to isolate the inner and outer parts of the nebula from the central star. The high-resolution (15 km/s) nebular spectra (910-1187 A) show strong emission from C III] and permitted transitions of He II N II, N III, S III, S IV, S VI and O VI, with stronger emission closer to the central star. In this paper we present results obtained on the spatial variation of these tracers of highly ionized gas. The hot central star of NGC 7009 is discussed in a separate paper by Sonneborn et al.