A 3-D model of the Helix Nebula shows a structure much more complex than suspected. The Helix Nebula is a planetary nebula, created when gas is expelled by a dying, Sun-sized star. The star becomes a white dwarf — look for it in the center of the Helix.
Find out more on HubbleSite: http://hubblesite.org/newscenter/archive/releases/2004/32/