Pelican Nebula Ionization Front

This is a false color composite image of the ionization front at the edge of the Pelican Nebula (IC5070) in the constellation Cygnus. By using narrow filters centered around the specific emission lines we expect to see from different elements in different states, we can determine exactly what physical process is responsible for the state of the nebula. In this instance, red comes from the H-alpha line at 656nm and blue-green comes from the SII line at 672nm. This image was obtained with the 2048x2048 pixel CCD (T2KA) at the 0.9 meter telescope of the Kitt Peak National Observatory near Tucson, Arizona.