Dumbbell nebula pumps out infrared light in this image from NASA's Spitzer Space Telescope. It was discovered in 1764 by Charles Messier, who included it as the 27th member of his famous catalog of nebulous objects. Planetary nebulae, historically named for their resemblance to gas-giant planets, are now known to be the remains of stars that once looked a lot like our sun. The Dumbbell nebula is 1,360 light-years away in the Vulpecula constellation, and stretches across 4.5 light-years of space. The diffuse green glow, which is brightest near the center, is probably from hot gas atoms being heated by the ultraviolet light from the central white dwarf. A collection of clumps fill the central part of the nebula, and red-colored radial spokes extend well beyond. This image was made using data from Spitzer's infrared array camera. Blue shows infrared light with wavelengths of 3.6 microns, green represents 4.5-micron light and red, 8.0-micron light.