This is M27, AKA the Dumbbell Nebula. It’s a planetary nebula. They are called planetary nebula because many of them in early telescopes looked like fuzzy little planets. It was once thought they were planets still forming.
They are actually made when a red giant star explodes and throws off a large part of its mass into the surrounding space. What makes these especially neat is they are only visible for a few ten thousand years or so. Relatively short in the scale of the universe.
This is one of the largest and brightest in the night sky.
This is a narrowband image made up of 2 channels. Red is the Hydrogen-alpha and the green/blue is Oxygen III. Looking closely at these two channels allows one to see the specific structures for each ionized gases.
This is made up of 25.8 total hours of exposure.
3nm OIII: 69×600″ (gain: 139.00) -15C bin 1×1
Ha 7nm: 86×600″ (gain: 139.00) -15C bin 1×1
Integration: 25.8 hours
RA center: 299.905 degrees
DEC center: 22.720 degrees
Pixel scale: 0.679 arcsec/pixel
Orientation: 269.108 degrees
Field radius: 0.537 degrees
I took several passes at processing this. The dynamic range is huge. The outer halo is very faint, while the inner parts of the core, by contrast, are fairly bright. This required layering various image and blending them together in addition to carefully blending the two primary channels to ensure the structural details were preserved and well represented.