NGC 6820 is a small reflection nebula that includes some impressive gas pillars only a little less spectacular than the Pillars of Creation in the Eagle Nebula made famous by Hubble. The pillars themselves lie near the open cluster NGC 6823, which is about 50 light years across at a distance of about 6,000 ly. The cluster contains a number of bright, young blue stars. This whole region is embedded in Sh 2-186, a large faint emission nebula that is too big to be seen in this narrow field image. In the sky, M27 the Dumbbell nebula lies only a few degrees away.

I found this to be a really tough object to image and it's taken me over a year to finally release the results. This image contains some of the last data that I took from Bend in the spring of 2017 before I moved my scope down to New Mexico. During that time, the seeing was spectacular and I snagged some of the best data that I've ever taken. FWHM in one frame bumped up against 1.0" arc-sec. Of course that never happens when I point the scope at a small galaxy!

After collecting this data, I took multiple runs at processing it but I could never reach a point that made me happy so I kept putting it aside. The problem with this region is that the Ha signal far exceeds anything else--particularly the OIII emission, which is VERY weak. I quickly learned that this is NOT an easy narrowband target to process! I figured that out fairly early during the run and that's why I took so much SII and OIII data. Still, every now and again, I've returned to this data set to see if I could process it and I never got it "right"--until now--and even then, it's just not a region that's easy to present in a very "eye-popping" way. It's a delicate act to balance the signal strength in the three channels against noise, which often leads to chasing down remedies for minor artifacts. I'm reasonably satisfied with this result and I think that I've hit a point of diminishing returns so it's time to set it free.

As always, C&C is welcome and appreciated so let me know what you think.

John

Version E: I finally had a little time to try to "punch up" this image a bit. Saturation and "clarity" have been tweaked a bit. Ultimately, this object might need another 20 hours of data to really get it where I'd like it. I've probably pushed it right up to (and maybe a bit beyond) the edge with this amount of data.