The partial star cluster in the upper left is M52. It is a large and bright open cluster in Cassiopeia. Below are links to an images that shows the entire cluster and the nebula.
I had originally intended to collect RGB data to make a full color image. But excessive smoke from extensive forest fires that summer prevented me from finishing the project. The smoke was relentless and continued almost until September. Then it rained and snowed for most of September.
By the time the weather cleared in October, the Bubble nebula was well out of reach for imaging. So what you see is all I got: 11 hours of H-alpha. I did actually try RGB one night during the smoke. The data was bad. No surprise there but I had to try it at least once just to make sure.
