This Nasa handout shows a composite view of four planetary nebulas from the first systematic survey of such objects in the solar neighbourhood made with Nasa's Chandra X-ray Observatory. The planetary nebulas shown here are NGC 6543 (aka the Cat's Eye), NGC 7662, NGC 7009 and NGC 6826. 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. Reuters/Nasa/STScI/Handout