Astr111 Photography Projects, Fall 2005

Little Dumbbell Nebula, Briana Cady

The Little Dumbbell is a planetary nebula in the constellation Perseus. A planetary nebula forms when a star throws off its outer layers after it has run out of fuel to burn. These outer layers of gas expand into space, forming a nebula which is often the shape of a ring or bubble. About 200 years ago, William Herschel called these spherical clouds planetary nebulae because they were round like the planets. At the center of a planetary nebula the glowing, left-over central part of the star from which it came can usually still be seen.(1) The Little Dumbbell was discovered by Pierre Mechain on September 5, 1780, but it wasn't until 1918 that is was correctly classified it as a planetary nebula for the first time by Heber D. Curtis.

The nebula is surrounded by a faint halo of material that was probably ejected from the star during its formation. This halo has a faint green tint to it, which indicates there is oxygen within the halo. This is an interesting fact because the oxygen released by this star essentially is the source of oxygen (along with many other nebulas) for our planet. There is also a slight red tint throughout the object which indicates it also contains hydrogen. The distance for the Little Dumbbell is poorly known, (which is not uncommon for planetary nebulas) with estimates around 3400 light years. The approximate linear size of the nebula is 2.97 light years.

References:

Students for the Exploration of and Development of Space

Cool Cosmos