Crescent Nebula and the Soap Bubble

This is an emission nebula in the constellation Cygnus, about 5000 light years from Earth. It is formed by fast stellar wind from a Wolf-Rayet star colliding with and energizing slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves. In the lower left of the image you'll see the Soap Bubble nebula, a planetary nebula discovered by an amateur astronomer on Jun 19, 2007 using just a 160mm refractor. This is one of those targets I loved to capture when I first started AP. The challenge was always trying to pull out the Oiii nebulosity without mangling the fine details. This was very frustrating till I realized I just needed to get a lot more data on the target to do it correctly, especially from my Bortle 7 location.