I posted an image of CTA 1 a little while ago. Here's it's somewhat brighter brother, CTB 1.
Supernova remnant CTB 1 in Cassiopeia is the remains of a violently exploding star. It's approximately 10,000 light-years away and occurred between 7,500 and 11,000 years ago, shortly before I went to school.
Captured at SRO California, Aug-Nov, 2017.
Scope: Ceravolo C300 @ f/4.9 = 1470mm FL
Mount: AP1100
Camera: FLI PL16803
Filters: Astrodon
Image scale: 1.26 arcsec/pixel (Drizzled to double res)
Exposures: 11x300s R, 11x300s G, 11x300s B, 49x1800s Ha, 53x1800 Oiii, 55x1800s Sii (total: 81.25 hours)
Processing: PixInsight 1.8.5
Processing credit: Rick Stevenson
Acquisition credit: Scott Johnson, Augusto Hernandez, John Kasianowicz, Daniele Malleo, Jose Mtanous and Rick Stevenson
Bigger version on Astrobin:
https://www.astrobin.com/full/334214/0/