This Sharpless nebula was one of the most difficult objects I ever tried to shoot. On the one hand the object (classified as an emission nebula - whether it is a planetary nebula? There are different opinions on that...) is very faint, on the other hand the object was located below Polaris during my shootings, which confused the mount a bit and always hit SH2-174 on the wrong side of the meridian. Extra difficult and I had to take care that my Epsilon did not collide with the mounting base.
In 12 nights I could gain exactly 50 hours of usable image material. Enough to make the even weaker extensions visible. My version of SH2-174 looks a bit untypical because of its depth and reminds me more of the shape of an eye, which you look at from the side.
Enclosed is an excerpt from the Sharpless catalogue (
http://www.sharplesscatalog.com/):
SH2-174 ranks as the most northern Sharpless objects at 81 degrees north. SH2-178 very close to Polaris is most likely part of the galactic dust cloud above is just to the north of SH2-174. The brighter area picks up well with a hydrogen-alpha filter or standard red filter. However the fainter area around the bright part really works well with only the H-Alpha filter. You will need a very long exposure to pick that part of it up. Large telescopes will not only show more structure, but show more detail in the reflection part of this area. The Oxygen III did not do well at all so SH2-174 does not make for a good narrowband color image. You will need a great deal of RGB data or the color will come out weak. In addition, the H-Alpha is fairly strong where the reflection part of this image is seen so a composite is needed to retain it.
I hope you like it! :-)
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