Chandra Release - October 10, 2012

Visual Description: NGC 6543

 Four striking images of planetary nebulas are shown, each with a slightly different color and shape but an overall feeling of similarity. There is a similarity to looking at four snowflakes under a microscope. The dominant colors range from pink to purple and blue to gold, and the shapes vary from slightly circular to more extremely oval-shaped. These nebulae have been captured in both X-ray and optical light. X-ray emission from Chandra is colored purple and optical emission from the Hubble Space Telescope is colored red, green and blue. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. A wind from the hot core rams into the ejected atmosphere, creating the shell-like filamentary structures seen with optical telescopes. The diffuse X-ray emission is caused by shock waves as the wind collides with the ejected atmosphere. The properties of the X-ray point sources in the center of about half of the planetary nebulas suggest that many central stars responsible for ejecting planetary nebulas have companion stars.  The planetary nebulas shown here are, from top, left to right, and bottom left to right:   NGC 6543 (aka the Cat's Eye), NGC 7662, NGC 7009 and NGC 6826.