M27, the Dumbbell Nebula

This nebula was formed when the star at the center of it aged and grew in size until its outer laters blew off into space. When a star of a certain size ages, its hydrogen spent, its core begins to collapse. As it does so, it grows hotter, and the helium and oxygen created earlier through hydrogen fusion then begin to fuse into heavier elements, such as carbon. In this stage, radiation from the shrinking center of the star pushes out on the outer layers of the star, which expands outward to become what we call a red giant. Eventually, the pressure in the center will be so great, the temperatures there so hot, the radiation outward so energetic, and the other layers so far away from the fusing core that the outer layers will be blown by the radiation out into space, forming a planetary nebula. The Dumbbell nebula is a fine example, as is M57, the Ring Nebula. The Dumbbell gained its name because, when seen visually through a telescope, the brighter parts of the nebula look like two attached lobes.

This image was taken with the Atik 16 through the AT66ED, guided with the DSI Pro through the 100mm f/6 on the Tak EM-10. The 99x90" subframes were processed first in Nebulosity and then in PSE7. Thanks to tips from the Spark labs forum, autoguiding is getting better. Every frame in this over-two-hour set was excellent. It could be better still.