Echelle observations of the giant halo of the planetary nebula NGC 6543 - II. Kinematics

Spatially resolved observations at high spectral resolution of the [O III]5007-Å line profiles from the faint, giant halo of the planetary nebula NGC 6543 have been obtained with the Manchester echelle spectrometer combined with the Isaac Newton Telescope. These show that the halo is relatively kinematically inert, having FWHM of the turbulent components (including bulk motions) of the observed profiles of only $$6.7 \pm 0.8\,\text{km}\,\text{s}^{-1}$$. An upper limit on any possible systematic expansion of the halo was found to be $$4.5 \,\text{km}\,\text{s}^{-1}$$. This is less than the anticipated expansion velocity of 10 km s^–1 in a red giant ‘superwind’.