M27, the Dumbbell Nebula

Planetary nebulae are the outer layers of defunct stars, puffed off into space as they become unstable at the end of their lives as normal stars. The remnant star is a white dwarf whose intense ultraviolet radiation excites the dispersing gas to glow. The Dumbbell is one of the most prominent of these and is located in the obscure constellation Vulpecula. Their blue-green color is often intense enough to see through a telescope. The red colors are a lot harder to pick up.

This was made with my 155mm refractor on a windless night, which is critical to success when using that big telescope on my relatively small mount.