The global kinematics of the Dumbbell planetary nebula (NGC 6853, M27, PN G060.8-03.6)

Spatially resolved profiles of the HeII 6560 A, Halpha and [N II] 6548 & 6584 A nebular emission lines have been obtained in two orthogonal long cuts over the Dumbbell planetary nebula. The central HeII 6560 A emitting volume of the bright dumbbell structure is shown to be particularly inert with an expansion velocity of <= 7 km/s. This is enveloped by an inner [O III] 5007 A emitting shell expanding at 13 km/s, an outer [O III] 5007 A shell expanding at 31 km/s which is on the inside of the outer [N II] 6584 A emitting shell expanding at 35 km/s. A new Halpha + [N II] 6548 & 6584 A continuum-subtracted image of the 15' diameter halo has also been compared with recent proper motion measurements of the central star and the present line profiles from the halo's inner edge. Interaction with the ambient interstellar medium is suggested. The bright [N II] 6584 A emitting shell must be running into this relatively inert halo with a differential velocity of >= 25 km/s. The present results are compared with currents models for the creation of planetary nebulae.