The elegant, delicate Cat's Eye is one of the most processed nebulas in the archive. With that in mind, the data was surprisingly a pain to get, being apparently available only as exposures and requiring a DADS request. It was strangely clean for uncombined images, though, and I suspect something got misplaced somewhere along the line.

Anyway, I decided I didn't want to go overboard on the processing. The concentric rings are meant to be faint. Intricate knots of Hα are highlighted and sharpened in red and yellow while OIII glows brightly in blue, my favorite colors for both of those filters.

I do wish I understood the nuances of the filters better. Both f656n and f658n are listed as Hα and I somehow managed to put the longer wavelength in the green channel instead of the red but it seems to look good like that anyway. Or maybe I mislabeled it. The data was kind of a mess.

It should be noted that a lot of the nebula is <a href="http://apod.nasa.gov/apod/ap070629.html" rel="nofollow">only visible in a wider field</a>. This is only the inner portion or iris of the Cat's Eye.

Red: f656n Green: f658n