NGC 6543 The Cat's Eye Nebula - 68 hours

[Petergoodhew]

A very bright planetary nebula in the constellation of Draco.

68h30m total integration (52x1800s OIII, 75x1800s Ha, RGB all 20x300s). Captured on my dual rig APM TMB 152 setup.

The core was captured on my Celestron C11 in London (500x10s luminance)

e-Eye, Spain 15/3-28/4/2019.

 

 

Edited May 21, 2019 by Petergoodhew
Stars tightened as proposed by Olly, remove dust bunnies

[Allinthehead]

Wonderful, and 68 hrs? That would take me a full season of imaging.

[Ibbo!]

Lovely image.

Thanks for posting the details.

I have started this again the other night to go with the data from last year and did wonder how you managed the core.

[Petergoodhew]

2 minutes ago, Ibbo! said:

and did wonder how you managed the core

I found the core the most difficult part. It is extremely bright and also very small.  I tried several techniques for trying to capture it using the 6" refractors, including very short Ha exposures - but I just couldn't get the resolution I wanted - hence resorting to my C11 in light poluuted London - but the brightness of the core was sufficient to get through the light pollution.  I used Registax to process the core, using planetary imaging techniques, and then combined in Photoshop.  Good luck. It's a very beautiful target.

[PhotoGav]

This is a wonderful piece of work with impressive dedication to get those integration hours! How strong is the signal in Ha and in OIII? Which is stronger? I’m guessing OIII from the colour.

[mikey2000]

When I saw 68hours, I just had to take a look (I normally only manage 68 minutes...!)   A remarkable result with splendid detail in that tiny little core

[wornish]

68 Hours !  Wow.  My max to date is 2.5 hours, being in cloudy, rainy, windy, Cheshire.

Your image is amazing well done.

[Petergoodhew]

2 minutes ago, wornish said:

68 Hours !  Wow.  My max to date is 2.5 hours, being in cloudy, rainy, windy, Cheshire.

Your image is amazing well done.

Thanks Dave. I know the feeling - here in London I also have light pollution and the Heatrow approach path to contend with!  Decent Spanish weather and dark skies do make a massive difference.

[Petergoodhew]

2 hours ago, PhotoGav said:

This is a wonderful piece of work with impressive dedication to get those integration hours! How strong is the signal in Ha and in OIII? Which is stronger? I’m guessing OIII from the colour.

Thanks Gav.  Both are strong - but the OIII is by far the stronger.  They tend to have the same structure - so the OIII sits on top of the Ha.  With 37 hours of Ha I had hoped for more from it!

[ollypenrice]

The core is bright but the outer shells not so and in this rendition the outer shells are lovely and clean while still being bold. You put my own 15 hours of integration to shame! This really is clean and bright.

Since the image is close to perfect I'll be really picky and say that, using layers, you could tighten up the brighter stars in the starfield.  Please take this as a compliment because I'm driven to nit-picking here!!! What a truly classy image!

Olly

Edited May 19, 2019 by ollypenrice

[Petergoodhew]

1 minute ago, ollypenrice said:

The core is bright but the outer shells not so and in this rendition the outer shells are lovely and clean while still being bold. You put my own 15 hours of integration to shame! This really is clean and bright.

Since the image is close to perfect I'll be really picky and say that, using layers, you could tighten up the brighter stars in the starfield.  Please take this as a compliment because I'm driven to nit-picking here!!!

Olly

Thanks Olly. Please do nit-pick away! Your guidance and constructive criticism over the years has been invaluable to me, and I still feel that I've a lot to learn.  I'll have a go at tightening them up.

Peter

[MarsG76]

That looks great but 68 hours??? WOW.... what focal length is that imaged at??? Native C11 FL or Hyper star?

 

[Petergoodhew]

6 minutes ago, MarsG76 said:

what focal length is that imaged at??? Native C11 FL or Hyper star?

Most was captured at 1200mm FL on the APM TMB 152 refractors. The core was captured on the C11 native at 2880 FL.

[MarsG76]

1 minute ago, Petergoodhew said:

Most was captured at 1200mm FL on the APM TMB 152 refractors. The core was captured on the C11 native at 2880 FL.

Nice.... well done, looks great...

[gorann]

Great image with an ingenious combination of scopes - letting the old London scope help out by looking through the fog where the Spannish one could not reach. I like the idea of mixing FL and exposure times to tame objects like this.

[ollypenrice]

Peter, I've just realized that you used the C11 for core luminance. I found that the core revealed most of its detail in Ha. I didn't use a longer FL for the core because I don't have one available but I suspect that you'd find more detail in Ha. Just a thought.

Olly

[Petergoodhew]

6 hours ago, ollypenrice said:

Peter, I've just realized that you used the C11 for core luminance. I found that the core revealed most of its detail in Ha. I didn't use a longer FL for the core because I don't have one available but I suspect that you'd find more detail in Ha. Just a thought.

Olly

Thanks Olly.  I'll have to give that a try.  I did luminance because I don't have a filter wheel fitted yet!  But I will give it a try with Ha when fitted.  I have horrendous seeing here in London - which is very evident at 2880 focal length! So it will be interesting to see how the longer exposures in Ha come out.

PS where can I see your Cat's Eye?

Edited May 20, 2019 by Petergoodhew

[ollypenrice]

39 minutes ago, Petergoodhew said:

Thanks Olly.  I'll have to give that a try.  I did luminance because I don't have a filter wheel fitted yet!  But I will give it a try with Ha when fitted.  I have horrendous seeing here in London - which is very evident at 2880 focal length! So it will be interesting to see how the longer exposures in Ha come out.

PS where can I see your Cat's Eye?

It's on here somewhere but I can't find it! It's also on Astrobin: https://www.astrobin.com/full/365412/0/?real=&mod= I'd like to get the outer parts a bit brighter with more data. It has a murky look about it! I've tried to upload the Ha core but it won't let me for some reason.

Olly

 

[ollypenrice]

Aha, it's working now, Peter. Although we're talking tiny, the Ha found a nice little pair of propellor-like extensions just out of the inner core.

Olly

[Petergoodhew]

Olly, that’s pretty impressive. Was that on the TEC140? I failed to get anything like that with my TMBs in Ha.

[Tom OD]

Super pic Peter. I love the 68hrs, and that little galaxy on the lower left.

The background is super smooth which I like.

My only criticism is that there are 2 dust bunnies on the top right hand corner.

Tom.

[Petergoodhew]

1 hour ago, Tom OD said:

Super pic Peter. I love the 68hrs, and that little galaxy on the lower left.

The background is super smooth which I like.

My only criticism is that there are 2 dust bunnies on the top right hand corner.

Tom.

Thanks Tom - I'll take a look.  These bunnies have a knack of sneaking in when I'm not watching!

Peter

[ollypenrice]

12 hours ago, Petergoodhew said:

Olly, that’s pretty impressive. Was that on the TEC140? I failed to get anything like that with my TMBs in Ha.

Yes, TEC140 and Baader 7nm Ha filter. For the core I used 14x120 seconds. Are you sure you didn't get them? If you were using the Astrodon 3nm I suppose it's just possible that they are shining in the NII line but it seems unlikely. Maybe they were drowned in longer Ha exposures?

Olly

Edited May 22, 2019 by ollypenrice
Correction of exp. times.

[Petergoodhew]

9 minutes ago, ollypenrice said:

Are you sure you didn't get them? If you were using the Astrodon 3nm I suppose it's just possible that they are shining in the NII line but it seems unlikely.

I've no longer the data but failed to see these when I tried processing.  I'll shoot more data and give it another try. How long were your exposures for the core? I was using Astrodon 5nm for Ha so it should be ok.  It's a massively challenging target - but an invaluable learning experience.

Peter

Edited May 22, 2019 by Petergoodhew

[ollypenrice]

7 minutes ago, Petergoodhew said:

I've no longer the data but failed to see these when I tried processing.  I'll shoot more data and give it another try. How long were your exposures for the core? I was using Astrodon 5nm for Ha so it should be ok.  It's a massively challenging target - but an invaluable learning experience.

Peter

I used 120 seconds for the core in Ha. I tried longer and shorter but found that about right.

Olly