On the discovery of an enormous ionized halo around the hot DO white dwarf PG 1034 + 001

Very recently, the discovery of the largest known planetary nebula on the sky surrounding the DO white dwarf PG 1034+001 with an apparent diameter of about 2 • , corresponding to a linear diameter of 3.5-7.0 pc at the likely distance of 100-200 pc, has been reported by Hewett et al. (2003). A careful inspection of available sky survey data has now shown that this planetary nebula, Hewett 1, is surrounded by an elliptical emission shell with an apparent diameter of 6 • × 9 • (16.2 +58 −43 pc). A further emission structure, detected northeast of the central star may indicate another shell with a size of 10 • × 16 •. ¿From presently available observational data we do not have indications whether the emission arises from material which was ejected from PG 1034+001 or from ionized ambient ISM. Improved proper motion data combined with radial velocity and distance from the literature have enabled us to derive a Galactic orbit for the central star PG 1034+001. Its thin disk orbit and the morphology of the first halo suggest that the nebula is in an advanced stage of interaction with the interstellar medium.