The Bubble Nebula is the result of a hot, massive star blowing out a fierce wind, as well as ionizing the material in the molecular cloud surrounding it. By using several narrow band filters, ttsounis was able to pick out the various flavors of elements making up the gas, including hydrogen, oxygen, and sulfur. "Fingers" of material, towers being eroded by the stellar wind (as in the famous Pillars of Creation M16 image), are obvious in the picture as well.