We last shot this one several years ago, with the STL-11000M. This is 3 hours each R,G,B using an Aspen CG16M on a 20" PlaneWave, taken on the only two decent nights in a month.
Notice the wizened figure of Master Yoda emerging from under a mist of reflection nebulosity. He is wearing a shapeless dark cloak, and holding a yellow walking stick in his twisted, arthritic, reddened hand. The red blob beyond the bottom of the walking stick is part of HH100.
Also of interest is the face-on spiral at the bottom edge, surprising given all the crowding and dust.
A pity is what we think is streaks from distant Gamma CrA, far out of field to the left. They converge to the right spot.
An awesome image Mike. Those red Ha areas actually in the blue reflection neb are they real? I have never seen those before. I see a few areas of red neb which I have seen before but your image is showing them in several areas.
Is this your 20 inch and dark skies picking up what is usually not seen or is it Ha noise from a Ha sub? I imaged this last week with the Trius on the CDK17 and it gave much the same FOV. Unfortunately in my case I think I may need to recollimate my CDK or at least get the camera really square and also the filter wheel acted up.
Echoing others, a beautiful image, lovely colours and detail. Just not sure about those red areas that Greg has mentioned, and maybe satellite trail could go away? Sorry for being picky, but I just loved soaking in detail in your photo and thus I spotted presence of the dark side...
Greg, I suspect that there are at least four small red blobs in the blue reflection nebula that are artifact. I'll try to see where they snuck in, and how they got past data rejection. Meanwhile, the big intense red blob at the bottom of the thumbnail of the walking stick is definitely real. Hope your filter wheel behaves better than my outlier rejection algorithm.
Just been going over the red spots mentioned by Greg and Slawomir. They are in every single red sub, just barely there but definite in the green subs, and totally absent from the blue subs. The filters are cycled R, G, B, R, G, B ... and across two nights, so it seems unlikely to be residual image "ghosting", because that would affect the first sub or two, but not subsequent ones. It's something that knows what filter is there. BUT, they don't look real. On the raw subs, they look like out of focus stars. I'm only using monochrome one-size-fits-all flats, so it's not a dodgy red flat. Some speck of grease on the red filter that spreads the light, but somehow has a hint in the same spot on the green filter ? Aaaugh! What a nightmare! Will have to look at images of other objects at the same spot.
Slawomir, there were FOUR satellites that went through the image. Most got automatically rejected. One incredibly bright, tumbling thing went through the very first sub just after Trish clicked "Expose". We saw it in the guide scope. That one missed the blender. I'll have a go at manually removing it from the particular sub.
Absolutely stunning! I hope to get to that level someday.
Here is a close 100% crop of the same region I took as a widefield of the whole cloud on Monday if it helps with your blobs. (Yours is still inverted I think?) I didn't even realise the biggest one here was actually an emission region and thought it was an artifact myself!
Greg and Slawomir, I found This APOD shot by University of North Carolina using a 32" scope at extreme altitude at Cerro Tololo. It's the "Answer in the Back of the Book". There are two faint but intensely red star-blobs towards ten o'clock from Yoda's head, and a few other smaller red splotches around Yoda's scone, which prove to be real, and are possibly HH related. In M&T's image, there are three red blobs more or less along the line of the horizontal diffraction spike from the top ultrabright star. These are artifact. (We notice they're not in Mike Sidonio's or Dylan's shots either). We'll seek them out and destroy them utterly in the next version. Destroy them, we will.
Nicely done M&T. Detail level is feathery and tight. Stars are very round. That galaxy in the right hand lower corner is pretty interesting to look at too.
I think you should look at the dark rings around the stars though.
Thanks for chasing it up Mike. So those spots either side of the bright stars in the blue neb are real? Someone else's image is not conclusive as they may have though they were artifacts and deleted them using the healing brush. But they are perfectly round unlike the other patches of red.
I wonder if a Ha exposure of this area would clear it up. If I get my filter wheel sorted quickly enough I think I will image this on my CDK and see what comes up. Its worth adding a Ha layer as there is more there than I think most of us thought.
What's HH stand for?
Greg.
Quote:
Originally Posted by Placidus
Jase and Dylan, thanks muchly.
Greg and Slawomir, I found This APOD shot by University of North Carolina using a 32" scope at extreme altitude at Cerro Tololo. It's the "Answer in the Back of the Book". There are two faint but intensely red star-blobs towards ten o'clock from Yoda's head, and a few other smaller red splotches around Yoda's scone, which prove to be real, and are possibly HH related. In M&T's image, there are three red blobs more or less along the line of the horizontal diffraction spike from the top ultrabright star. These are artifact. (We notice they're not in Mike Sidonio's or Dylan's shots either). We'll seek them out and destroy them utterly in the next version. Destroy them, we will.
Nicely done M&T. Detail level is feathery and tight. Stars are very round. That galaxy in the right hand lower corner is pretty interesting to look at too.
I think you should look at the dark rings around the stars though.
Thanks Paul. Your point about the dark rings is especially important because one or two of the stars really do have a little clear lacuna around them, presumably as a result of radiation pressure or stellar wind, and having sharpening artifact panda eyes around the others detracts from that.
Independently of all that, we're wondering whether it is worth doing some really deep subs in narrowband. We finally found an annotated ESO VLT shot that shows where the Herbig-Haro jets and objects are. Very different to what we thought, based on useless text descriptions by everyone from AAO to APOD, and well worth a glimpse.
Thank you for looking up the relevant APOD image and for confirming the nature of red areas. I really like exteriorisation of stellar influences on cosmic dust surrounding the central bright star - I have never seen that before.
Stunning image Mike and Trish, and a great story to go along with it. The detail in the whisps of nebulosity are very beautiful, and the little red nebs add another point of interest. Great job guys!
