New Clues to the Most Amazing Shapes in Space

[mickw]

The term "planetary nebula" has always been a misnomer, but these spectacular clouds of dust and gas may actually have something to do with planets after all, astronomers have found.
When astronomers discovered these celestial objects 300 years ago, they couldn't tell what they were and so named them for the resemblance they had to the planet Uranus as seen through early, relatively crude telescopes. But by the mid-19th century, it was realized that they were actually great clouds of dust emitted by dying stars

More:  http://www.space.com/scienceastronomy/080318-st-planetary-nebulae.html