Helix Nebula. Optical photograph of the Helix Nebula (NGC 7293),a planetary nebula located approximately 450 light years away in the constellation of Aquarius. The bright ring of emission is an expanding shell of ionised gas which was ejected by the dying,central star. Most low-mass stars,including our own Sun,are expected to expel planetary nebulae towards the end of their lives. The unusual helical structure of NGC 7293 may be due to the central star orbiting an invisible companion star. The Helix Nebula is the nearest known planetary nebula to Earth | |
Licence : | Droits gérés |
Crédit: | Science Photo Library |
Taille de l’image : | 4736 px × 3774 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |