The Dumbbell Nebula - M27

Getting around to completing the postprocessing of a number of astro objects in my backlog. Part of my backlog of image runs, this image contains subs taken over the period August 8, 10, 11 and September 1 and 2, 2023.

The Dumbbell Nebula (M27) - Aug/Sep 2023
EdgeHD-11 / ASI2600mm Pro
Hubble Palette (HOO) - total integration time: 14h 15m

The Dumbbell Nebula, also known as Messier 27, and NGC 6853, is a planetary nebula located in the constellation Vulpecula, approximately 1360 light-years away from us. It was the first planetary nebula to be discovered by Charles Messier in 1764. It appears as an elongated spheroid from our perspective along the plane of its equator. Based on its angular expansion rate of 2.3 arcseconds per century, M27 has an estimated age of 14,600 years.  Its apparent magnitude of 7.4 makes it one of the largest and brightest planetary nebulae in the sky. (Wiki)

Planetary nebulae are clouds of gas and dust that form when a star like the Sun dies. The star's outer layers are shed, forming the nebula, while the core becomes a white dwarf. The nebula's complex chemicals glow in interesting colors when lit by the white dwarf. It is the light from this glow, mainly from excited Hydrogen gas (Hα) and Oxygen (Oiii), that my photographic filters allow through to the camera sensor - all other light is blocked. Images taken in this way are known as narrowband images since they only contain light from a very narrow band of the electromagnetic spectrum. The Hubble Palette includes Hα, Oiii and Sii (Sulphur). Since there is very little contribution from Sii in M27's light, I used a modified Hubble Palette which only captures Hα and Oiii (known as the HOO palette).

Since M27 glows very bright in normal light as well, here is the same image taken with RGB subs, 20 of each color (broadband imaging, at an exposure of only 60 seconds each for comparison.  

M27 - RGB
EdgeHD-11 / ASI2600mm Pro
20x60sec - total integration time: 1hr