The Dumbbell Nebula (Expanding Planetary Nebula)

In 1764, Charles Messier discovered the first planetary nebula - the Dumbbell Nebula (M27 or NGC 6853). Located in the constellation Vulpecula, the Dumbbell, being a very bright planetary nebula, is easily visible when viewed through binoculars or amateur telescopes. This is the type of nebula that will be produced by our Sun when it runs out of the nuclear fuel that makes up its core, estimated to occur in 5-8 billion years.

Photo Credit: Joe & Gail Metcalf, Adam Block, NOAO, AURA, NSF

Planetary nebulae, unrelated to our solar system's planets, were designated as such due to the similarities they appear to share with the giant planets when seen through smaller telescopes. These nebulae have a relatively short life span; only in the tens of thousands of years as compared to the typical lifetime of a star, generally several billions of years. The estimated age of the Dumbbell Nebula is somewhere between 3,000 and 4,000 years, just a baby in space time.

The Dumbbell was formed when its central star, similar to our own Sun, began running low on the hydrogen that is necessary to fuel its life. As the hydrogen is depleted, the star begins burning other gases within its nuclei, including oxygen, helium and carbon. The stellar core is compacted and the outer layers begin to expand. During unstable periods, the star may eject these layers completely. What is left in place of the original core is a white dwarf star. The white dwarf in the Dumbbell is the largest known white dwarf in the solar system.

The newly-formed white dwarf star is small but extremely hot due to nuclear burning. The energy from this nuclear burning radiates away from the star, causing the ejected layers, or shells, to fluoresce. The Dumbbell's shell is expanding outward at roughly 17 miles per second, as found by Bohuski, Smith and Weedman in 1970. This expansion will continue for billions of years until all of the energy has been depleted, leaving a black dwarf in place of the star.

For Help Locating This Object in the Sky: Use the Interactive Messier Map in the upper right hand corner. Objects are listed numerically. Click on the object you wish to locate (ex. The Crab Nebula is M1) and a map will be displayed showing that object's location.

Author Resource: Written by Starr Hendon