The kidney-bean shape in the center is a shell of gas ejected by a massive, hot central star. The shell of gas hits a surrounding molecular cloud (the faint outer shells), and the radiation from the central star causes everything to glow. Litebox 15" F/5 Dobsonian, 13mm LVW eyepiece (147x) + OIII filter. Anza-Borrego desert, CA. 2008-10-31.