Here are RGB, O III & H-Alpha images using my new filter wheel. It is at a distance of approximately 3300 light years ( Very uncertain )

https://en.wikipedia.org/wiki/Cat%27s_Eye_Nebula

It was discovered by William Herschel on February 15, 1786
https://en.wikipedia.org/wiki/William_Herschel

Time: 00:29UT 2026-05-09 Filter & Exp. R(31x30) G(9x65) B(11x65) Sec

Time: 00:29UT 2026-05-09 Filter & Exp. H-Alpha(19x245) O-III(21x245) Sec
Tel: C14 @ f/4.1 ST-7 CCD @ -25°C 1.28"/pix Paramount GT-1100S
Odd Trondal Obs.code 238 (Uranium). Oslo Norway.

And remember O-III is O++. And as Don Lincoln say "Physics is everything"

https://en.wikipedia.org/wiki/Doubly_ionized_oxygen