14,000 years ago the small, blue star in the heart of this image began to puff off its outer surface. The star still glows blue because it is a high mass end PNe star. Note the “lopsided” appearance of the expanding shell of material. The density of space is different on either side of the star – thicker to the left side where the material is piling up like a traffic jam, and thinner to the right where the shell has mostly dissipated.
12 1/2″ Ritchey-Chretien Telescope with an ST10XE/CFW8. F/6 RRGB (19/7minR,5/5min2x2RGB scaled on MaximDL at 1.3R,1.0G, and 1.7B.