* Astronomy

Born-again planetary nebula

Although nuclear burning of hydrogen and helium had ceased in the core of the dying star, causing it to collapse under its own weight and its envelope to expand into a bubble, some of the stars outer layers became so dense that fusion of helium resumed there. 
The renewed nuclear activity triggered another, much faster wind, blowing more material away. The interplay between old and new outflows has shaped the clouds complex structure, including the radial filaments that can be seen streaming from the collapsing star at the centre.
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