NGC 7293: The Helix Nebula . ... Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula , typical of this final phase of stellar evolution. ... It shows details of the Helix's brighter inner region , about 3 light-years across, but also follows fainter outer halo features that give the nebula a span of well over six light-years. The white dot at the Helix's center is this Planetary Nebula's hot, central star . ...