On the discovery of an enormous ionized halo around the hot DO white   dwarf PG1034+001
  Very recently, the discovery of the largest known planetary nebula on the sky surrounding the DO white dwarf PG1034+001 with an apparent diameter of about 2 degrees, 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 times 9 degrees (16.2 +6.1/-4.5 times 24.3 +9.1/-6.8 pc at d = 155 +58/-43 pc. A further emission structure, detected northeast of the central star may indicate another shell with a size of 10 times 16 degr. From presently available observational data we do not have indications whether the emission arises from material which was ejected from PG1034+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 PG1034+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. 
Thomas Rauch (1 and 2), Florian Kerber (3) and Eva-Maria Pauli (1)   ((1) Dr.-Remeis-Sternwarte, Bamberg, Germany, (2) Insti...