When is a Planetary Nebula not a Planetary Nebula ?
Abell 35 while initially classified as a planetary nebula is according to recent research likely to be a Stromgren sphere. The object is ionized by an unseen hot white dwarf companion of BD – 22º 3467, as BD – 22º 3467 is not hot enough to ionize the nebula.
There is a powerful parabolic bow-shock wave structure around the bright star BD – 22º 3467 which is very evident in the OIII narrowband component of the image. The nebula itself is estimated to be moving through the interstellar medium at Mach 10 which is causing a shock wave and the resulting linear structures of the nebula.
Imaged in H alpha, Oxygen III and RGB on our Planewave CDK 700 at Observatorio El Sauce, Chile.
Image Processing: Mike Selby