The 'Bubble Nebula is aptly named.The nebula (NGC7635) is one of three shells of gas surrounding the massive star BD+602522, the bright star near the center of the bubble. Energetic radiation from the star ionizes the shell, causing it to glow. About six light-years in diameter, the Bubble Nebula is located in the direction of the constellation Cassiopeia. This is a 3 hour image taken on October 21, 2009. It has 3 hours exposed through a hydrogen-alpha filter, and one hour through RGB filters. The Hyperion Astrograph is attached to an SBIG-STL11000M ccd camera.