A one hour integration of 100-second shots. Stacked in Deep Sky Stacker. Finished in Photoshop

The Bubble nebula (NGC 7635) in Casseopia is such an amazing target! Its bubble is formed by a super hot star emitting radiation outward in the HII region. It is a magnitude 10 target (rather dim) and so I was not sure if I could get much data from it, but I am pleased that the bubble was so well-formed in the result! The light pollution filter under dark skies allows for longer exposures and more HII data to get through without blowing out the exposure from skyglow.