Astr110 Photography Projects, Fall 2005

Cocoon Nebula, Tyler Boyd & Katie Landan

The Cocoon Nebula was named for its faint, hazy, nebulosity around a main nebula in a cocoon-like form. The Cocoon Nebula consists of the open star cluster IC5146 in the Cygnus constellation in our Milky Way galaxy. An open star cluster is defined as a group of forming stars located in the disk of a galaxy. Stars in a open cluster typically have a common distance, age, and chemical composition but conversely, different masses. At the center of the nebula are new stars. Nebulae like this are deemed "stellar nurseries" making for emission, reflection, and absorption nebula.

The cocoon nebula boasts red spectral lines indicating the prevalence of hydrogen gas. As a developing nebula, the vibrant, swirling colors come from clouds of gas and dust; the raw materials for star formation. The exquisite colors are also a result of the unique combinations of emission and absorption nebulae.

This image was taken November 6, 2005. The most prominent features in this image are emission and absorption. The darker parts of the nebula is a result of the dust absorbing light. In contrast, the brighter, more colorful features of the nebula are characterized by emission. Recent research has yielded discussion that energy providing bright, center star opened a molecular cloud which thematerial passes through. In this medium, near the center star, Hydrogen gas is excited and emits light. The linear size of the nebula is about 9 LY across.

References:
http://www.paulandliz.org/Nebulae/Default.htm

The Cosmic Perspective, Bennet 3rd Edition (p. 536)

http://www.starrywonders.com/cocoon.html