Sharpless 68 (PN G030. 6 + 06. 2 ) is a very interesting planetary nebula visible in the eastern part of the Serpens constellation.
The first surprise met me when I tried to process the RGB signal of the stars that I intended to use in this work. I couldn't find a photo to show why I was having so much trouble with color balance until I came across a description of the Great Rift as a Milky Way object.
For those interested, you can read more at
https://skyandtelescope.org/observing/a-trip-down-the-great-rift/In my work, it is clear which stars lie between the Solar System and the Milky Way's galactic disk, and which are obscured by the disk.
Additionally, Sh2-68 is located in the densest concentration of this interstellar medium.
This of course also affects the nebula's brightness, which, with a low surface brightness estimated at 10 mag, does not make it easy to photograph. This obviously increased the necessary registration time.
While searching for curiosities, I came across a discussion whether, in view of the nebula's "shining through" the dust medium, its colour should also be more orange. I assumed that the dust attenuates but does not change the emission bands of particular elements and I left a typical red-blue bi-colour for the nebula.
And finally the matter of the "cometary tail" of ionized gas extending at least 30 arc minutes from the main body of the nebula . This tail is associated with the motion of the central star and is obviously a plume of matter left by Sh 2-68 moving through the orbit of the Galactic Disc. The existence of the tail is a direct confirmation of the interaction of Sh 2-68 with the interstellar medium (ISM) and highlights the likely important role of the ISM magnetic field.
You can read more about it at
https://www.researchgate.net/publication/248879684_Sh2-68_-_A_Planetary_Nebula_Leaving_it%27s_Mark_on_the_Interstellar_Medium
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