IC 1396 (Elephant's Trunk Region)

[steppenwolf]

IC 1396 (centred on The Elephant's Trunk Nebula region)

Introduction

The nebula is part of a rich area of emission nebulosity catalogued as IC 1396 in the constellation of Cepheus and lies about 2,450 light years away. In this image, only the ‘trunk’ region is shown but the object gets its name from the extended region to the north that forms the Elephant’s head, ears and the base of the trunk that then curves down and then up again in the typical poise of an elephant placing food in its mouth with its trunk! However, this fascinating and to me, slightly eerie feature reminds me less of an elephant's trunk and more of an alien apparition walking out of the mist!

The bright edge to the trunk itself is the compressed ridge of a dense ionized cloud that is being illuminated by the magnitude +5.7 star (HD 206267A) to its east whose powerful stellar wind is driving the formation of new stars. This massive star is part of the Trumpler 37 (Tr 37) star cluster. These same stellar winds are sculpting the wonderful shapes and filaments that are visible throughout the globular head of the nebula. The darker clouds are silhouetted against the backdrop of glowing hydrogen gas from the surrounding nebula, IC 1396.

Not visible in this image but worthy of note as it is just on the edge of IC 1396, is a bright red star named The Garnet Star by Sir William Herschel although it was originally discovered by Johann Bayer. Mag. +4.23 Mu Cephei to give it it’s Bayer identification, is a red supergiant believed to be the largest star visible to the naked eye, with a diameter of 3.86 billion miles across. That’s much further than here to the pub ......

The Elephant’s Trunk Nebula is wonderfully rich in Ha emissions and previously I have been content to produce a mono image using this filter but this time round I was determined to capture some OIII and SII data to produce a colour rendition. The OIII and SII proved to be very thin and the poor weather conditions resulted in a meagre amount of SII but I went for it anyway! I use Astrodon 3nm Ha and OIII filters but simply cannot afford the additional cost of an SII filter at this bandwidth so I used my 7nm Baader SII filter to complete this image. This bandwidth disparity introduces problems of its own with regard to star sizes so I had some fun and games removing halos caused by the SII data but finally came up with an image that I liked and present here. I also show the OIII and SII data for comparison so that you can see what I had to contend with when it came to processing. The Ha data was collected while the Moon was too prominent for any other filter and the other channels were captured whenever there was a break in the September clouds.

Image Stats

Mount: Mesu 200
Telescope: Sky-Watcher Esprit 150
Flattener: Sky-Watcher Esprit specific
Camera: QSI 683 WSG-8
Filter: Astrodon 3nm Ha, 3nm OIII and Baader 7nm
Subframes: 42 x 1800 sec Ha, 39 x 1800 sec OIII, 10x 1800 sec SII
Integration: 45.5 hours
Control: CCD Commander
Capture: MaxIm DL
Calibration, Stacking and Deconvolution: PixInsight
Post-Processing: PhotoShop PS3

Location

Constellation	Cepheus
RA	21° 35' 0.76"
DEC	+57° 29' 48.50"
Distance	2450ly

 

 

 

[Grant]

Wowsers Steve! That's absolutely stunning! 45+ hours! Wow, with our clear skies that must have taken ages!

I really like the way you've written it up and presented it, that must have taken a lot of effort but it's well worth it - thank you

[MartinFransson]

That´s an excellent image! The detail is awesome!

I see you found the same problems as I did - the amount of O3 and S2 in this region 🙂
And you also use the same filters as I do - Astrodon 3nm for Ha and O3 and Baader 7nm for S2. I had the exact same problems with star sizes and halos on the S2 data. I also had problems with haze in quite a lot of my O3 subs so I actually made two stacks. One with the cleanest data for better star shapes and one with all the data for the faint nebulosity. I then made a starless version of the full dataset and blended it into the stack with better stars.

[Kinch]

Great finish and a colouring I really like. It is 4 years since I did the 'trunk'.....must try it again soon.

[alan potts]

Incredible image Steve,  45 hours, I don't think I did that amount of time outside when we have just had 43 clear night on the bounce. Always wish I had got a 150mm when I have the chance to pick one up from the local dealer at 3500e, he was being kind to me as I was a good customer before he stopped trading.

Alan

[tomato]

Superb result, and as usual a very well presented and informative post, 45 hrs under a UK sky, nice one! 

That’s just 3 nights with a dual rig?

 

[steppenwolf]

16 hours ago, Grant said:

Wowsers Steve! That's absolutely stunning! 45+ hours! Wow, with our clear skies that must have taken ages!

Thanks, Grant, there was a spell of clear skies around the most recent full Moon (now there's a surprise!) so I captured all the Ha then, collected the OIII over 6 nights in August and the SII in one night (26th August) - in the UK, you have to take your chances when they appear!

16 hours ago, MartinFransson said:

That´s an excellent image! The detail is awesome!

I see you found the same problems as I did - the amount of O3 and S2 in this region 🙂

Thanks, Martin, yes, the OIII and SII seem very poor and despite the number of OIII subframes I was disappointed by the noise levels. This took a lot of processing and several notable failures!!

16 hours ago, Kinch said:

Great finish and a colouring I really like. It is 4 years since I did the 'trunk'.....must try it again soon.

Get back on it, it is a lovely object from close in and in a widefield view as MartinFransson has recently demonstrated.

16 hours ago, alan potts said:

Incredible image Steve,  45 hours, I don't think I did that amount of time outside when we have just had 43 clear night on the bounce. Always wish I had got a 150mm when I have the chance to pick one up from the local dealer at 3500e

Thanks, Alan - I do have the advantage of an observatory so I don't have to worry about sleep deprivation! The Esprit 150 is an amazing telescope, what a shame you missed this opportunity.

13 hours ago, tomato said:

Superb result, and as usual a very well presented and informative post, 45 hrs under a UK sky, nice one! 

That’s just 3 nights with a dual rig?

Thank you - hmmm 3 nights with your dual rig, I HATE YOU!! 🤣

[Rodd]

Very good data and processing--We all have opinions and likes/dislikes.....for me, I think a smidgen more saturation would add depth.

Rodd

[tomato]

On 27/09/2019 at 08:53, steppenwolf said:

 

Thank you - hmmm 3 nights with your dual rig, I HATE YOU!! 🤣

I think there is an old AP saying, “an Esprit 150 on the mount in the dome is worth two in their flight cases.” October is nearly upon us and the dome is still not up, but... it should get moved from the storage location at Tomatobro’s tomorrow.👍

[steppenwolf]

16 hours ago, Rodd said:

Very good data and processing--We all have opinions and likes/dislikes.....for me, I think a smidgen more saturation would add depth.

Here you go Rodd, just for you! 😁 I tend to slightly under-saturate this type of object to make it look more 'dusty'' but I like stronger colours too:-

14 hours ago, tomato said:

I think there is an old AP saying, “an Esprit 150 on the mount in the dome is worth two in their flight cases.” 

So true!!

[Laurin Dave]

That's fabulous Steve (not that the first wasn't!)..   excellent separation between the double star on the trunk, you don't often see that. Esprit150s..  don't you just love them.

Dave

[Rodd]

6 hours ago, steppenwolf said:

Here you go Rodd, just for you! 😁 I tend to slightly under-saturate this type of object to make it look more 'dusty'' but I like stronger colours too:-

WOW!!!--yes....what a shot.  And i agree about the double star--perfect.  BUT...why not post the full sized image?  i assume you down sampled as when I try full resolution it does not get bigger.  Let me tell you--this image DESRVES full resolution if I ever saw one that did!

Rodd

[jjosefsen]

Amazing image, and a great wealth of information to go with it. 👍

 

Is there somewhere I can pixel peep at 1:1 scale?

Edited September 28, 2019 by jjosefsen

[steppenwolf]

3 hours ago, Rodd said:

BUT...why not post the full sized image?  i assume you down sampled as when I try full resolution it does not get bigger.  Let me tell you--this image DESRVES full resolution if I ever saw one that did!

 

3 hours ago, jjosefsen said:

Is there somewhere I can pixel peep at 1:1 scale?

OK guys, here is the full resolution image for what it is worth (cropped a little to allow for an orientation mismatch caused by having to remove the camera to review some equipment ........):-

[Ouroboros]

Cracking image, Steve! So nice to have the additional info too.  

When you've got a long term project like this on the go do you leave everything set up for the one object or do you look or image other stuff too?  

[steppenwolf]

11 minutes ago, Ouroboros said:

Cracking image, Steve! So nice to have the additional info too.  

When you've got a long term project like this on the go do you leave everything set up for the one object or do you look or image other stuff too?  

Thanks for your comments. I usually just stick with one object unless it is only visible for a short period during darkness in which case I have a secondary target set up ready to go when the first passes my chosen 'horizon'. I always aim to get the most out of any clear night as they seem pretty scarce these days!

[steppenwolf]

9 hours ago, Laurin Dave said:

That's fabulous Steve (not that the first wasn't!)..   excellent separation between the double star on the trunk, you don't often see that. Esprit150s..  don't you just love them.

Thanks, Dave. Yes, I really wanted to separate those two stars but the 3nm Ha filter and deconvolution in PixInsight made that possible. Yes, I do love my Esprit 150 and to think that I nearly let it go early on as I really wanted a widefield instrument (but there wasn't anything that suited my requirement) and thought I had made a mistake! I certainly didn't make a mistake and wouldn't part with it now.

[Rodd]

👍!   Don’t let it go, but a wide field scope is awesome as well.  I need both.  Hard to imagine you couldn’t find a worthy widefield instrument 

Rodd

[steppenwolf]

12 hours ago, Rodd said:

Don’t let it go, but a wide field scope is awesome as well.  I need both.  Hard to imagine you couldn’t find a worthy widefield instrument 

Having gone through two Tak FSQ 85's which didn't perform as promised and then found from other people's experiences that QC on several other smaller widefield instruments was just too variable, I decided not to pursue that line until the industry got itself sorted out! So, I jumped the other way and bought the Esprit 150. I do have a semi-widefield instrument in my William Optics FLT-98 (fabulous optics) combined with a William Optics FR IV to give a focal length of just 509mm and reasonably impressive flat field if I follow a very rigid assembly procedure to negate the risk of tilt and get the spacing between the focal reducer and camera tuned correctly (I have a vernier scale on the FR IV for this very purpose!).

The Esprit 150 is a keeper as is the FLT-98 ........

[sloz1664]

Tremendous amount of detail there Steve. We've had a great run of clear skies recently and you have certainly used this time to gather the data. The processing is, as always, top drawer.

Steve

[steppenwolf]

1 hour ago, sloz1664 said:

Tremendous amount of detail there Steve. We've had a great run of clear skies recently and you have certainly used this time to gather the data. The processing is, as always, top drawer.

Thanks for your comments, Steve - to be able to image under full Moon conditions certainly helped me to get the subframe count up!

[Ruud]

Hi Steve. It's amazing. I'm speechless.

[Allinthehead]

That's a wonderful image Steve. My preference is for the first version. Looks more natural.

[morimarty]

Excellent image Steve, very clean, vibrant colour, and lovely tight stars👍

[steppenwolf]

18 hours ago, Ruud said:

Hi Steve. It's amazing. I'm speechless.

Thank you Rudd, I'm pleased you like it 👍

18 hours ago, Allinthehead said:

That's a wonderful image Steve. My preference is for the first version. Looks more natural.

Thank you Richard, colour is such a variable thing. I like subdued colours as they make deep sky images look more 'dusty' which I guess is why I settled for my first rendition but the more saturated version also brings out some added depth! It is not unusual for me to do several orisons and in fact, my original is in fact two versions combined .......

16 hours ago, morimarty said:

Excellent image Steve, very clean, vibrant colour, and lovely tight stars👍

Thanks, Martyn much appreciated.