NGC 2392, located about 4,200 light years from Earth, is a dying star nicknamed the Eskimo Nebula -- what astronomers call a planetary nebula. Planetary nebulas actually have nothing to do with planets, but the objects looked like planetary disks to earlier astronomers looking through small optical telescopes.
Planetary nebulas form when a star uses up all of the hydrogen in its core -- an event our sun will go through in about five billion years.
When this happens, the star begins to cool and expand, increasing its radius by tens to hundreds of times its original size. Outer layers of the star are carried away by a 50,000 kilometer per hour wind, leaving behind a hot core.
This core has a surface temperature of about 50,000 degrees Celsius, and is ejecting its outer layers in a wind traveling six million kilometers per hour. The radiation from the star and the interaction of its fast wind with the slower wind creates the complex shell of a planetary nebula.
Eventually the remnant star will collapse to form a white dwarf star.
This composite image of NGC 2392 contains X-ray data from Chandra in purple showing the location of million-degree gas near the center of the planetary nebula.
Data from the Hubble Space Telescope show the intricate pattern of the outer layers of the star that have been ejected in red, green and blue.
The comet-shaped filaments form when the faster wind and radiation from the central star interact with cooler shells of dust and gas that were already ejected by the star.