M27 - Dumbbell Nebula

[jase (Jason)]

Need a couple dumbbells StrongmanMike?

Hi All,
Back to business after the recent CWAS posts. In an attempt to cater for different tastes, my latest efforts have leaded me down two paths of which I’m pleased to present:

M27 – Dumbbell nebula in true colour for the traditionalists.
True colour image is a Ha [Ha+R]GB composite totalling 4.7 hours (Ha:120mins;R:55mins;G:55mins;B55mi ns).

and...

M27 – Dumbbell nebula in mapped colour for the NB aficionado (Fred, Ric and others).

NB image is a SII:Ha:OIII (Hubble Palette) composite totalling 4.3 hours (SII:70mins;Ha:120mins;OIII:70mins)

About the target;
The Dumbbell nebula (M27) is a gaseous emission nebula residing in the constellation Vulpecula. Its name was derived from early astronomers who sighted it has having two distinctly shaped sides looking like a Dumbbell weight. The shape of the nebula is due to the central star expelling its layers as its core nuclear fuel supply diminishes. M27 resides 1,200 light years away.

Some words on the image (Usual bantering for those interested):

All NB data was acquired using Lightbuckets 24” RCOS (4876mm @ F/8) under the pristine dark skies of New Mexico. Attached to the business end of the scope is the Apogee Alta U42 CCD camera which is a great match for this instrument (NABG, back illuminated, high QE, good sampling, 100k well depth – enough said). The camera is deceptive – I would have thought it would bloom on the Ha filter on 600sec subs, but it didn’t. It may with a different field i.e. a bright star present but around the dumbbell this wasn’t an issue. Rather impressive to capture the outer shell in only 120mins of Ha data. I guess that's what sensitivity coupled with 600mm aperture will provide. This optical system will devour any galaxy in its sight. Big drool factor.

OK, with that rant out the way on to the more interesting side of imaging, the processing. Ha data was acquired on the Dumbbell as it crossed the meridian so was of great quality. No meridian flips - it’s an eq. fork. For the purpose of this exercise, I’m only going to explain the narrowband processing. If you want info on how I conducted the processing on the true colour data, pls PM me – it was similar to the M83 image where I used RGB data from a different focal length system to colour the high resolution luminance – a bit of star colour matching required – not fun.. Anyway, subs calibrated in MaximDL, registered in Registar and then combined using Sigma Reject back in MaximDL. Ha, SII and OIII combined files passed through 2 iterations of LR deconvolution. Proceeded to perform an initial stretch in DDP. The stretch wasn’t aggressive i.e. to fill the full bit space, but mild. This is to make the clipping masks a little easier to deal with in the next phase. I thought I’d try the Hubble palette on this target even though I knew I wouldn’t shine towards green Ha nebulosity. I’ve seen a few other renditions such as CFHT (Canada-France-Hawaii Telescope) aka HOS and also simple Ha and OIII (bi-colour mapping). So SII:Ha:OIII were mapped to R:G:B respectively. I introduced each layer into PS and began creating clipping masks. I used the same process in which Dr. Travis Rector utilises to map some of the Hubble images. I’m not going to cover the specific clipping mask process here. You’ll find a white paper by Dr. Rector under the resources section of my site titled “Creation of Presentation-Quality Astronomical images”. A worthy read if you’re looking to step up your imaging output. Further stretch images using curves (as clipping masks). Image was then flattened after clipping masks looked close to bring out each emission line. The dumbbell does not contain much SII data. Looking at the subs, the signal is rather weak. Ha and OIII (particularly OIII – raw data sample of OIII) are very strong. The SII data is shown as a yellow hue as it mixes with the green Ha data. No mixing of Ha into the other channels to provide resolution – nothing but clean emission lines here. The background noise in the NB image is due to stretching the SII rather hard – classic example of a weak signal (I should have masked it). May look at doing a Ha:OIII rendition in the future. Strangely, I’m starting to warm to the SHO palette despite the green Ha data!

Quick note on the RGB version, the RGB was acquired sometime ago (actually last year) using a TOA-150/ST10XME. I did have intentions to use the 24” RC to collect the RGB data, but with full moon around at the moment, I thought I’d try my hand a mixing different focal length data (yet again). I think some luminance data on this target would bring back the stars in a more pleasing manner. The Ha data stars were very tight and round which didn’t match well with the lower res RGB data. (Check out the star trio at top left – prime resolution as you would expect from this aperture).

Before I close, I’d like to say a few words about the Lightbuckets operation. Steve and Alvin have been exceptional to deal with during the data acquisition process. They are imagers at heart and take great pride in delivering the best possible data to you. While they are just warming up, they’ve completed an amazing array of features to make it easier to image remotely. From configuring a “set and forget” fully automated acquisition session through to intricate details of a flats library for any potential imaging angle you choose, thus providing flat field accuracy. Incredible work and dedication. Again, like GRAS, I’m not associated with their operations (this is based on personal experience), I’m simply a user of their services.

Anyway, hope you enjoy them.
Hmmm (5m F/L)…Nothing like a bit of deep space in your face! YEAH!

Cheers

[leon]

Wow Jase, an other master piece as expected, although both are excellent, I do prefer the first, but that is MHO only, awesome shooting

Leon

[strongmanmike (Michael)]

Originally Posted by jase

Need a couple dumbbells StrongmanMike?

Hmm?..lets see? That star would have been at least as heavy as our Sun soooooo thats 10 to the power of 30 kg or so of expploded gasses plus a white dwarf...?...yeh! EASY!

Your posts are becoming bloody books Jase

Very nice dumbell image and yes I agree, to reveal this in such a short exposure is pretty cool...A dumbell image without the faint outer ejecta is becoming a pretty ordinary image these days

I want a high QE/well depth CCD now

MIke

[skeltz (Rob)]

I think it looks like my brain,about to explode after trying to understand all these processing techniques:
But seriously ,they look **** hot and i would say i like the real colour one best.
At least with remote imaging you can get clear skys somewhere

[renormalised (Carl)]

Great piccies, Jase. Both of them

I like both traditional and mapped colour data, they both have their place and can look as good as one another. If done correctly, they can both bring out a lot of good detail that's scientifically useful when studying nebula etc.

[Bassnut (Fred)]

Totally awesome Jase, the nebula extension and core detail is exceptional.

On zooming in (im allowed to, given the gear list ) there seems to be a bit of colour noise in the background, but that could be the upscaled RGB data you added, and given the object is pretty dim, even 4hrs odd is not a lot of time.

Interestingly star halos are stronger on the true colour image, usually the NB suffers that problem more, but you used Ha on the true colour image too, so that might explain that.

When the colour data is not the best, I find using Ha as a lumanence channel in NB (as in Ha;sII;Ha;OIII) allows detail boost, but of course colour is then somewhat washed out and the colour channels need lum added (as you seem to be good at).

All in all, a wonderfull effort Jase, its the 1st lightbuckets customer image Ive seen, ive been waiting for that, and its impressive I must say.

We live in interesting times .

[iceman (Mike)]

Wow, now that took me by surprise. I don't think i've seen anything quite like it from the ground before. A 24" scope, now that is something.

Simply amazing, Jase.

Remote imaging really delivers the goods, and at an infinitely small percentage of what it would cost to acquire that gear yourself.

[Tamtarn]

A simply stunning image Jase. Never seen such detail in M27 before the outer detail is awesome. Thanks for sharing such a fine image.
24" RCOS - 4876mm F/L - 4.7hrs

We'll have to give it a go with the Skywatcher

[Alchemy (Clive)]

everyone else seems to like the normal one, i actually prefer the mapped version.

the detail in the Ha emision is lovely within the nebula on both images... i presume its the same data.

i find the halos around the stars on the RGB one distracting to me,( i did note you could improve it with more data in your disertion at the start).
given your processing skills i think you could improve on the sky background noise too.

[jase (Jason)]

Originally Posted by leon

Wow Jase, an other master piece as expected, although both are excellent, I do prefer the first, but that is MHO only, awesome shooting

Leon

Thanks for your comments Leon. Yes, a true colour image is always a crowd pleaser. Narrowband takes some getting use to. I enjoy working with narrowband has it allows for more creative expression.

Originally Posted by strongmanmike

Hmm?..lets see? That star would have been at least as heavy as our Sun soooooo thats 10 to the power of 30 kg or so of expploded gasses plus a white dwarf...?...yeh! EASY!

Your posts are becoming bloody books Jase

Very nice dumbell image and yes I agree, to reveal this in such a short exposure is pretty cool...A dumbell image without the faint outer ejecta is becoming a pretty ordinary image these days

I want a high QE/well depth CCD now

MIke

Cheers Mike. Reading the blurb is optional mate. One day, I’ll shock you by just posting a link to the image. Agree, you know when you’ve done this target justice when you see the fainter features/ejecta. I hear you regarding high QE/well depth. The Alta U42 has a peak QE of >90% @ 550nm. Leaves the KAI-11002 for dead. Time for an upgrade?

Originally Posted by rpsastronomy

I think it looks like my brain,about to explode after trying to understand all these processing techniques:
But seriously ,they look **** hot and i would say i like the real colour one best.
At least with remote imaging you can get clear skys somewhere

Thanks Rob. Providing you know the principles of processing, that’s all that counts. I have a few routines I use. I’m still learning the ropes. Yes, the joys of remote imaging. Though its not always clear, but you do increase your chances of acquiring data.

Originally Posted by renormalised

Great piccies, Jase. Both of them

I like both traditional and mapped colour data, they both have their place and can look as good as one another. If done correctly, they can both bring out a lot of good detail that's scientifically useful when studying nebula etc.

Thanks Renormalised. I still feel NB imaging is rather artistic over scientific. You still strive for something aesthetic. Takes a while warm to pink stars for example. I don’t think the SHO palette is ideal for this target, hence may rework the data another time.

Originally Posted by Bassnut

Totally awesome Jase, the nebula extension and core detail is exceptional.

On zooming in (im allowed to, given the gear list ) there seems to be a bit of colour noise in the background, but that could be the upscaled RGB data you added, and given the object is pretty dim, even 4hrs odd is not a lot of time.

Interestingly star halos are stronger on the true colour image, usually the NB suffers that problem more, but you used Ha on the true colour image too, so that might explain that.

When the colour data is not the best, I find using Ha as a lumanence channel in NB (as in Ha;sII;Ha;OIII) allows detail boost, but of course colour is then somewhat washed out and the colour channels need lum added (as you seem to be good at).

All in all, a wonderfull effort Jase, its the 1st lightbuckets customer image Ive seen, ive been waiting for that, and its impressive I must say.

We live in interesting times .

Hey Fred, thanks for your comments. Yes, the background colour noise is the upscaled RGB. What do you expect when trying to match 1050mm data to 4876mm! A much better option was to acquire RGB on the 24”, but with the moon still bright, I thought I’d use some data previously acquired. Again the star halos are due to the upscaled RGB. As mentioned in the original post, I need luminance data to make the stars look normal. The Ha data stars are very tight/small. I did think about blending the Ha data into other emission lines i.e. make the blue channel a blended combination of OIII + .2 Ha to simulate H-beta. However, I decided on the cleanest emission lines possible. May rework the data in due time. Thanks again.

Originally Posted by iceman

Wow, now that took me by surprise. I don't think i've seen anything quite like it from the ground before. A 24" scope, now that is something.

Simply amazing, Jase.

Remote imaging really delivers the goods, and at an infinitely small percentage of what it would cost to acquire that gear yourself.

Cheers Mike. Yes, the 24” RCOS @ Lightbuckets is a killer set up. You’re right, remote imaging continues to mature. I feel many people are still somewhat overwhelmed by the prospects of taking an image remotely. It’s actually no different to acquiring data on your own equipment; it still needs to be processed in a similar manner. A great image is not handed to you on a silver platter, that’s for sure. You still need to work for it.

Originally Posted by Tamtarn

A simply stunning image Jase. Never seen such detail in M27 before the outer detail is awesome. Thanks for sharing such a fine image.
24" RCOS - 4876mm F/L - 4.7hrs

We'll have to give it a go with the Skywatcher

Thanks Barb and David. Pleased you liked it. Its good to see a comparison of both true and mapped colour I guess. I was originally only going to post the mapped colour.

Originally Posted by Alchemy

everyone else seems to like the normal one, i actually prefer the mapped version.

the detail in the Ha emision is lovely within the nebula on both images... i presume its the same data.

i find the halos around the stars on the RGB one distracting to me,( i did note you could improve it with more data in your disertion at the start).
given your processing skills i think you could improve on the sky background noise too.

Cheers Clive. Each to their own regarding true or mapped colour preferences. I don’t think SHO palette is the best for this target. Yes, the halos and background noise are from the upscaled RGB. It is complex to match the different FL data, especially if it’s mediocre (which was the case with the RGB). I’ll be looking to take RGB from the 24” assuming I don’t lose interest on this target. Thanks again.

[Ric]

Woo Hoo Jase, two superb images I love them both with a slight tendency towards the colour mapped image, of course.

I have never seen that much detail in any other image of M27 and I do enjoy reading your write ups and processing details.

As you mentioned colour mapping can be a great artistic release at times and I will be interested to see your variations on the SHO palette.

Cheers

[jase (Jason)]

Cheers Ric. Pleased you liked them. Indeed, I do intend to perform some variations to the NB palette. I suspect I'll go with a bi-colour composite - just Ha and OIII for this target assuming I can get the stars to look ok. Never easy. Thanks again.

[renormalised (Carl)]

Thing is, Jase, with SHO colour mapping is that, when done well, you're tracing the distribution of HII (as Ha), SII and OIII in the object you're looking at. That way, you can tell the chemical evolution of the nebula plus any stars/remnants which maybe linked to that nebula. Yes, they are artistic, but I wouldn't expect nature to be anything otherwise. NB pics just bring that out...and so do traditional RGB when done well.

[zipdrive (Dave)]

wow! fantastic work jase.

[Robert_T]

Hey Jase, what a fabulous insight into this nebula...my favourite is the mapped colour, looks like a giant inter-steller orchid bursting into bloom

[dcalleja]

Jase
Amazing work - I never knew PN's could have such huge extensions like that - It almost doesn't look like the same target.

I prefer the true colour version - but thats just me

[Garyh]

Wow factor plus some alright!
Love that true color rendition Jase!
Don`t think I have ever seen the shell quiet like that before!
Might have to use that as some wallpaper!
cheers Gary

[seeker372011 (Narayan)]

wow.

I vote with those who seem to prefer the RGB version...just so much detail.

with these deep images someone is going to have to rename the object ..hardly just a dumbell or an apple core anymore
Narayan

[gregbradley]

Amazing RGB image Jase. One of the very best I have seen of this object.

I for one like the blurb on the processing details as I find Photoshop and image processing is such a diverse and deep subject I like to find out more about it as I see the images I like. So thanks for the data.

Greg.

[jase (Jason)]

Originally Posted by renormalised

Thing is, Jase, with SHO colour mapping is that, when done well, you're tracing the distribution of HII (as Ha), SII and OIII in the object you're looking at. That way, you can tell the chemical evolution of the nebula plus any stars/remnants which maybe linked to that nebula. Yes, they are artistic, but I wouldn't expect nature to be anything otherwise. NB pics just bring that out...and so do traditional RGB when done well.

I hear you Renormalised. Though I think the SHO mapping doesn’t work well for every target…as is the case in this example. HOS or Bi colour appears to be the way to go for the dumbbell. Stay tuned, have started reworking the NB data set to come up with a Ha, OIII version. Thanks for your comments.

Originally Posted by zipdrive

wow! fantastic work jase.

Thanks Dave. Pleased you liked them.

Originally Posted by Robert_T

Hey Jase, what a fabulous insight into this nebula...my favourite is the mapped colour, looks like a giant inter-steller orchid bursting into bloom

Cheers Rob. Never thought of it as an interstellar flower, but the analogy works!

Originally Posted by dcalleja

Jase
Amazing work - I never knew PN's could have such huge extensions like that - It almost doesn't look like the same target.

I prefer the true colour version - but thats just me

Thanks Dan. The nebulous shock waves certainly add an extra dimension. I pushed the data rather hard to get the extension out with only 600s subs. I hope to add 2hrs of Ha data using 900s to see what that will bring to the image.

Originally Posted by Garyh

Wow factor plus some alright!
Love that true color rendition Jase!
Don`t think I have ever seen the shell quiet like that before!
Might have to use that as some wallpaper!
cheers Gary

Cheers Gary. I’ve found it interesting to gauge the forum’s reaction between the true colour and narrowband. I did this before with IC1848 in true colour and mapped colour. Hold off on the wallpaper, I hope to have a better rendition coming.

Originally Posted by seeker372011

wow.

I vote with those who seem to prefer the RGB version...just so much detail.

with these deep images someone is going to have to rename the object ..hardly just a dumbell or an apple core anymore
Narayan

Thanks Narayan. Typically, people associate going deep with mega data. However, I feel this image goes to show that you don’t need mega data when you’ve got aperture and more importantly sensitivity. The Alta U42 is an excellent camera. It certainly not large format, but comes with some breath taking stats and price - http://www.bigbangastro.com/apogeeu4...ra-p-2812.html
The guys at Lightbuckets certainly have a remarkable set up.

Originally Posted by gregbradley

Amazing RGB image Jase. One of the very best I have seen of this object.

I for one like the blurb on the processing details as I find Photoshop and image processing is such a diverse and deep subject I like to find out more about it as I see the images I like. So thanks for the data.

Greg.

Thanks Greg. Pleased you don’t mind reading up on some of the techniques of used. More than happy to share the information/knowledge to benefit others.

========

Thanks again to all those who have made comment. Appreciate the feedback and kind words.