Well, another unplanned excursion with my dog in the wee hours, this time at 0200 hours. I gotta start getting up early, but with work it's kind of hard to do. So, what to look at? I had no plan. So, again, I decided just to revisit some Messier objects I was familiar with but had not seen in a few years. I always wanted to sketch Messier 108, so I decided to go look at it. But, I was not really dark adapted just yet, so I hopped up to the Owl for a quick look. I put in the Orion Ultrablock and it just jumped out at me.
So, before moving back to M108, I decided to see if I could detect the eyes. Always an elusive target. So, I stayed with it until I could determine where they are. Turns out, 67x was not enough, so I risked 100x and 120x and began to see some "sparkles" embedded in the nebula and I thought one of them was the central star, which I have not seen before. Still having some difficulty, I hit it with 150x trying to tease out those sparkles. Anyway, this was getting interesting, so I stayed with it as my dark adaption set in under the hood.
Turns out 150x was right at the edge where the nebula begin to loose too much surface brightness, and I would not risk any higher magnification. I know some folks have reported one eye is easier to see than the other. I guess this was true for me, too, as the smaller and higher contrast southern eye was more readily seen. But, I could make out the northern eye. Neither eye was held for long periods, just enough to determine they were oriented basically north and south with the more prominent eye to the south. The northern eye was more elusive and it turns out a little larger with less contrast. So, to me, the smaller southern eye was a bit easier.
All the while, though, I kept spotting the central star as it winked in and out of view. It did seem to be surrounded by a small dark area. I also caught one sparkle toward the western edge of the nebula, maybe another faint one just south, and a scattering of pretty faint stars just outside the nebula. It turns out, there are three stars, including the central star embedded, so I was reasonably sure I had caught two of them and maybe the third. They were visible, I dunno, maybe 30% of the time, along with the other brighter one, and the dimmer one less often seen. (The term "sparkle" is best because that was the thought that came to mind when I saw them).
Now, it also turns out there is what looks to be a very faint star trailing on the eastern edge of the nebula. I did catch an unmistakable sparkle there, too, a couple of times. But, that star (seen in images) appears to be much fainter than the already fleeting central star, so I don't think I saw it. Now, in some images (upon verification) there does seem to be a bright knot in the nebula also near the eastern limb. I do not know which detail I saw, it was a tiny and very fleeting sparkle. But I like to think I may have seen that nebulous knot, I've seen them before in other planetary nebulae like NGC 2022. So, maybe.
All the while observing the nebula for nearly an hour, I could not escape the impression or appearance the nebula was slightly brighter in the central regions. Some views with extreme averted vision showed the nebula to be very large with a well defined edge. But, normal observing it did appear slightly brighter toward the center. Not all the time, but sometimes the bright areas would "swirl" around the center then fade.
Now, make no mistake, the nebula is pretty bright itself, but the detail embedded within it is fairly tough with low contrast. It did not jump out at you like the a static sketch with somewhat embellished contrast to make it easier to see. But, when I put it all together in the sketch, it almost looks like an image. I was shocked. So much so, I almost did not Post it without toning it down a little. But, I felt that would be an injustice and you only live once. So, here it is all caution to the wind...this may be one of my better DSO sketches.
I hope the faint "sparkles" show well on your monitor, especially the strange one near the east edge of the nebula. Thanks for sharing.
Edit: Oh, by the way, I never did hit M108, but I did try Messier 51 for a while with no intent to sketch it. I mention it only because I used the Orion SkyGlow broad band filter on it. You know, I think it helped noticeably. Not significantly, but noticeably. The companion was pretty broad with a bright core, and the spiral structure was becoming evident with the filter. I could see the bridge between them at times and some dark and light interplay that were trying to show me the spiral arms. With more time on it, I am sure I would have seen them...with the filter!
Edited by Asbytec, 22 February 2020 - 10:35 PM.