Dumbbell Nebula

Messier 27 (NGC 6853), the Dumbbell Nebula, holds the distinction of being the first planetary nebula ever discovered. Charles Messier found it on July 12, 1764, and described it as an oval nebula without stars — puzzling, since planetary nebulae were not yet understood as a class. It was William Herschel who later gave them their misleading name, because in a small telescope their round, disk-like glow reminded him of the planets Uranus and Uranus. The Dumbbell lies approximately 1,360 light-years away in the small constellation Vulpecula, the Fox, and is the brightest planetary nebula in the sky, easily visible in binoculars.

NGC 6853 is the expanding shell of gas shed by a dying Sun-like star as it exhausted its nuclear fuel and collapsed into a white dwarf — the dense stellar remnant visible at the nebula's center. The white dwarf's intense ultraviolet radiation ionizes the surrounding gas, causing it to glow. The classic "dumbbell" shape — two lobes of brighter emission bridged by a fainter waist — is a product of the geometry of the ejection: material was shed preferentially along an equatorial belt, making the nebula appear lobed when viewed from our particular vantage point. The full extent of NGC 6853 is larger than its bright core suggests; long exposures reveal a much fainter outer envelope extending well beyond the familiar bright hourglass.

In binoculars the Dumbbell appears as a clearly non-stellar, oval glow; a small telescope at moderate power reveals the double-lobed silhouette that gives the nebula its name, and the central white dwarf becomes visible in a 200 mm aperture. This approximately true-color image was taken in July 2000 at the Kitt Peak National Observatory 2.1-meter telescope during the Research Experiences for Undergraduates (REU) program supported by the National Science Foundation; dynamic range was stretched to reveal the faint outer regions alongside the bright core.