Astr111 Photography Projects, Fall 2005

NGC281-PacMan Nebula Amanda Koopman

The Pacman Nebula is a diffuse emission nebula. An emission nebula absorbs ultraviolet radiation from other stars and then emits it as visible light. It lies 10 thousand light years away, is 35x30 arc minutes across, and rests near the constellation Cassiopeia. This picture is only 14x21 arc minutes across, which makes the nebula in this picture 61 light years across. The Bok globules are also noticeable in this picture. Bok globules are dense clouds of gas that do not let light through them. They are areas where stars are formed.

There are several important astronomical features in the Pacman nebula. First, there are many Bok globules. These globules indicate star forming areas, huge masses, and great sizes. Second, the brightest star in the picture is a multiple star system. It's light is used to ionize the gas in the nebula and is the cause of the red glow throughout the nebula. Third, the red color of the nebula indicates a prominence of Hydrogen gas.

References:
NGC Object List: http://www.seds.org/messier/xtra/similar/rasc-ngc.html
NASA: http://antwrp.gsfc.nasa.gov/apod/ap050823.html
Wikipedia: http://en.wikipedia.org/wiki/Pacman_Nebula AND http://en.wikipedia.org/wiki/Bok_globules