I had a few hour window of clear weather the other night before cloud came over.
I am planning to do more on this one but I was surprised at how well "only" 3 hours of data turned out. I guess that is the big advantage of aperture - the light gathering power. I am used to requiring more like 10 hours to get this level of signal. This could be handy given the vagaries of clouds and weather.
Planewave CDK 17, FLI Proline 16803 at -39C, Astrodon Gen 11 LRGB filters,
Paramount ME mount. I am continuing to tweak polar alignment using TPoint and it must be pretty close now after several runs through that and drift aligning. TPoint is a cool program and can be used with any mount and camera.
I also suspect there is a largish star tidal stream going from that yellowish bottom galaxy back to the main spiral arms. Longer exposure may prove it to be there or not.
Meeeeh.. so, so....be nice to remove those gradients of course but as you say the light gathering capability shows promise for sure! The image scale is showing its advantage too, both this and the NGC 253 show real fine body. I assume that's the full field? If so the correction is perfect and any image tilt is insignificant, nice!
Hmmmm..you look to have just lassood that outer arm and the galaxy and brightened them though, this is always tempting to do but it isn't real. No way of telling what might be a tidal stream and what is just gradient, would be hard to remove the gradients without removing the tidal stream though..?
There definitely were some gradients. My home observatory is reasonably dark but not as dark as at Bigga.
Perhaps the larger aperture also picks up the light pollution more as well? Or it probably was there anyway for the APOs
but it takes longer to get the signal? Not sure.
I'll be adding more to this one as its in a good position early in the evening whilst waiting for other targets to rise.
As you say the correction seems perfect which is always a worry with a large chipped camera.
The tidal stream I think may be there (as you say it may not be due to some light pollution) is the bottom right down to the yellowish galaxy.
The tidal stream to the left was enhanced a bit but not by lasso.
I have a feeling that yellowish galaxy is nowhere near NGC6744. That tidal stream is just a matter of juxtaposition. But then again, I maybe wrong as I don't know how far away that small galaxy is.
There is a tidal stream there, though. See the companion above the main spiral (the "bar" running perpendicular to the spiral...it's a Magellanic Class barred irregular), there's a definite trail of stars and (most likely) gas there. As a matter of fact, if you look closely, you can see very faint OB associations in the stream. There's most likely also a degree of very distorted spiral arm from the main galaxy mixed in there as well.
However, there's definitely distortion of the main spiral from its companion and some faint trailers there. Poor little galaxy is getting the life sucked out of it!!!
Here is 3hrs 40min worth and again enhanced but this time taken from pristene dark skies at 1000m elevation, once again lots of faint cirrus everywhere but nothing else really..?
I've been watching with interest how this new scope will perform, the detail within the core is pretty much on a par with mikes much longer exposure certainly at a quick look at a lower res. However being as mike has put up his as a comparison....... The colors in the two are very different, if I had to make a choice I'd say his were on the money, and I cant see that all that extra exposure would make that much difference in the color dept..... Smoother yes, push it harder for faint detail yes but color ........ Hmmmm.
On a positive note I myself haven't done an image which in retrospect couldn't be improved. I get to a point after a couple hours of processing where you've got so many versions Im not sure just what it should look like.
However being as mike has put up his as a comparison.......
Just to clarify, I wasn't putting mine up as comparison at all, rather just referencing a deep enhanced negative and B&W version to show there was no tidal stream, that was all. I wasn't directly comparing my colour image to Gregs at all and didn't link to that version .
Here is 3hrs 40min worth and again enhanced but this time taken from pristene dark skies at 1000m elevation, once again lots of faint cirrus everywhere but nothing else really..?
Mike
There's no tidal stream to where Greg mentioned...it's the cirrus, but there is one if you look at the NGC6744A and the distorted spiral arm and stream of stars from the main galaxy. It's faint and you have to know what to look for, but it's there
There's no tidal stream to where Greg mentioned...it's the cirrus, but there is one if you look at the NGC6744A and the distorted spiral arm and stream of stars from the main galaxy. It's faint and you have to know what to look for, but it's there
Yeeeeeeh.... but, tidal steams are more commonly noticed around more edge on galaxies, they tend to get a bit lost when looking down on a galaxy.
I have a feeling that yellowish galaxy is nowhere near NGC6744. That tidal stream is just a matter of juxtaposition. But then again, I maybe wrong as I don't know how far away that small galaxy is.
There is a tidal stream there, though. See the companion above the main spiral (the "bar" running perpendicular to the spiral...it's a Magellanic Class barred irregular), there's a definite trail of stars and (most likely) gas there. As a matter of fact, if you look closely, you can see very faint OB associations in the stream. There's most likely also a degree of very distorted spiral arm from the main galaxy mixed in there as well.
Yes looking at it again I think you are right. But I just saw an R Jay Gabany 20 hour image of M83 which has been imaged to death and it had huge loopy tidal streams. I'd say these streams are pretty common but they just need super dark skies and very long exposure.
Quote:
Originally Posted by strongmanmike
Here is a contrast enhanced view of 4.5hrs worth - can't see much there other than galactic cirrus
Quote:
Originally Posted by strongmanmike
Here is 3hrs 40min worth and again enhanced but this time taken from pristene dark skies at 1000m elevation, once again lots of faint cirrus everywhere but nothing else really..?
Mike
It seems there is a very faint longish spiral arm going out the bottom part like the top half has or am I seeing something out of nothing?
Quote:
Originally Posted by Alchemy
I've been watching with interest how this new scope will perform, the detail within the core is pretty much on a par with mikes much longer exposure certainly at a quick look at a lower res. However being as mike has put up his as a comparison....... The colors in the two are very different, if I had to make a choice I'd say his were on the money, and I cant see that all that extra exposure would make that much difference in the color dept..... Smoother yes, push it harder for faint detail yes but color ........ Hmmmm.
On a positive note I myself haven't done an image which in retrospect couldn't be improved. I get to a point after a couple hours of processing where you've got so many versions Im not sure just what it should look like.
Hmm, very hard to say at this early point. So far the CDK picks up more detail compared to other images I have taken of the same thing. Looking at my image again it really does need the extra hours. Tonight is shaping up pretty well. I'll take some more exposure and see how it works out. Also my southern skies could be a tad darker here. I am picking up a bit of light pollution also. I did fight against a green bias in the colour and that usually means light pollution. Perhaps there was some high cloud as well. Tonight seems very clear so far.
I mainly put it up as a work in progress. I was happy to get that much out of 3 hours on this rather faint galaxy.
Quote:
Originally Posted by strongmanmike
Just to clarify, I wasn't putting mine up as comparison at all, rather just referencing a deep enhanced negative and B&W version to show there was no tidal stream, that was all. I wasn't directly comparing my colour image to Gregs at all and didn't link to that version .
Mike
yep I realised that.
Quote:
Originally Posted by renormalised
There's no tidal stream to where Greg mentioned...it's the cirrus, but there is one if you look at the NGC6744A and the distorted spiral arm and stream of stars from the main galaxy. It's faint and you have to know what to look for, but it's there
Also it seems to extend a bit past that irregular companion galaxy.
Just to clarify, I wasn't putting mine up as comparison at all, rather just referencing a deep enhanced negative and B&W version to show there was no tidal stream, that was all. I wasn't directly comparing my colour image to Gregs at all and didn't link to that version .
Mike
Sorry, the image I looked at was the 1 Meg when i looked at other versions of the same image, And yes poor choice of words on my part.
Perhaps I should have just said, the color doesn't quite seem there.
be nice to remove those gradients of course but as you say the light gathering capability shows promise for sure! The image scale is showing its advantage too, both this and the NGC 253 show real fine body. I assume that's the full field? If so the correction is perfect and any image tilt is insignificant, nice!
