Image: Cat's Eye Halo

Description: An enormous but extremely faint halo of gaseous material surrounds the Cat's Eye Nebula and is over three light-years across. Within the past years some planetary nebulae been found to have halos like this one, likely formed of material ejected during earlier active episodes in the star's evolution - most likely some 50,000 to 90,000 years ago.
Title: Cat's Eye Halo
Credit: http://www.spacetelescope.org/images/heic0414b/
Author: Nordic Optical Telescope and Romano Corradi
Permission: http://www.spacetelescope.org/copyright/
Usage Terms: Creative Commons Attribution 3.0
License: CC BY 3.0
License Link: http://creativecommons.org/licenses/by/3.0
Attribution Required?: Yes