NGC 6543: A planetary nebula, also known as the Cat's Eye.
Caption: The Chandra X-ray Observatory image on the left shows a bright central star surrounded by a cloud of multimillion-degree gas in the planetary nebula known as the Cat's Eye. The central star is expected to collapse into a white dwarf in a few million years. In the right panel, a composite image by Chandra (purple) and by the Hubble Space Telescope (red and green) shows where the hot, X-ray emitting gas appears in relation to the cooler material seen in optical wavelengths. A planetary nebula (so called because it looks like a planet when viewed with a small telescope) is formed when a dying red giant star puffs off its outer layer, leaving behind a hot central core.
Scale: Image is 30 arcsec on a side.
Chandra X-ray Observatory ACIS /ACIS Image