Abell 39 is a planetary nebula in Hercules. Planetary Nebulae have nothing to do with planets but are the outer atmosphere of a star that was blown off during the last phase of it’s fusion cycle and is now being energized by the light coming from the white dwarf left after the star stops fusing material.

Planetary nebula are relatively transient phenomena. As the gas expands and becomes more diffuse it eventually disappears from view. Perhaps someday, billions of years from now, some of that gas will merge with some other gas and contribute to the formation of a new star.

This particular nebula is estimated to be about 11,000 years old and around 3,800 light years away. It’s fairly faint and probably only accessible photographically to most amateurs.

The image processing for this is slightly unusual. It’s an ORGB image. The RGB part is from the normal red-green-blue color filters. That is what provides all the color in this image. The O is from the Oxygen III filter, a narrowband filter tuned specifically for Oxygen emission. I used the O filter data as a luminance layer which helped bring out what detail there is.

For all the technical details, see astrobin.