In the Shadow of the Horsehead

[SkyViking]

Hi All,

Despite the intermittent clear skies lately I have now managed to finish the first proper image with my new 12.5" scope.
In order to assess the new scope's capabilities I chose a target slightly less obscure than normal: The Horsehead Nebula and NGC2023. Oh well, I guess one is not really an astrophotographer without an image of this classic under one's belt. :lol::P

Link to full resolution image (3MB) (http://www.rolfolsenastrophotography.com/Astrophotography/Nebulae/i-68QBqR4/O)

About the image:
The Horsehead Nebula (also known as Barnard 33) is without doubt one of the most recognized and fascinating objects in the sky. This iconic feature is formed by the sharp outline of a dark dust cloud, with a remarkable likeness to a horse's head, silhouetted against a brightly glowing patch of ionized Hydrogen (IC434) that is being energized by the hard ultraviolet radiation from nearby Sigma Orionis, a quintuplet star system lying just outside the top of the image.

I sought to process this image to show not only the Horsehead silhouette but also the details of the dense dust cloud (Lynds 1630 molecular cloud) from which it emerges.
The background behind the Horsehead glows with a soft diffuse reddish/pinkish light because of strong emission by spectral lines from ionized Hydrogen. Visible in the foreground is the large looming shadow being cast by the Horsehead's tower of dust, appearing as a dark fan-shape down towards the bottom centre-left, intercepted on its left edge by the intricate bright blue reflection nebula NGC2023. In contrast to the red emission glow, the reflection nebula is caused by light from the nebula's bright blue central stars which is being reflected off the surrounding dust.The brightest member of the central cluster is the B star HD 37903, a very young star with intense ultraviolet radiation that has carved a four light years wide cavity in the dust that we see as the reflection nebula.

Throughout the dark cloud, both in and below the Horsehead, are several small glowing reddish patches. These are the feeble lights from new stars being born in the cloud. Some of these are Herbig-Haro objects; the result of plasma jets ejected from young protostars which collide with the sourrounding gas and dust and cause the glowing emission. Inside the bright blue nebula NGC2023 are also several brightly coloured wisps of emission patches, further hints of young stellar objects and the regions' overall complexity and beauty.

The Horsehead Nebula is located around 1,500 light years distant towards the constellation of Orion. It was discovered in 1888 by Williamina Fleming on a photographic plate (#B2312) taken at Harvard College Observatory. She described the bright emission nebula later designated IC434 as having “a semicircular indentation 5 minutes in diameter 30 minutes south of Zeta [Orionis].”
She was never credited with the discovery though because Dreyer did not include her name when he compiled the Index Catalogue (IC) in 1895 and 1908.

Image details:
Date: 7th, 8th, 9th, 20th, 26th, 27th, 28th, 31st December 2013 and 2nd, 5th, 6th, 9th January 2014
Exposure: LRGB: 460:65:65:60 mins, total 10 hours 50 mins @ -25C
Telescope: 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

I'm very happy with how the scope is performing. There are considerable improvements over the 10" in most areas. Light gathering power is fantastic and resolution is markedly improved. This particular image was taken in average seeing conditions, most nights were rather humid and stars were not as crisp as I have seen them at times with the new scope back in November. But once the weather gets a bit more settled here I'd expect more steady imaging conditions, like last summer which was great here.:thumbsup:

All comments and critique welcome.

Regards,
Rolf

[strongmanmike]

Congratulations You are now an astrophotographer :prey: :bowdown:

Nice result indeed Rolf with lots to see :thumbsup: the 7hrs of Lum has allowed you to reveal lots of dust too (nice pink neb BTW :whistle: ). You have controlled that flare from the left very well and the detail is great but perhaps the general processing/sharpening(?) is a tad obvious at full size :question: but it looks great at size X3-Large and smaller :thumbsup:

Onwards and upwards with the new mini Hale now :thumbsup:

Mike

[gregbradley]

Beautiful!

Greg.

[alpal]

Hi Rolf,
that's one of the beast horse head's I've ever seen.
The detail is amazing.

cheers
Allan

[RobF]

Stunning work Rolf. Amazing to have it humming so well, so soon after finishing and installing. Congrats. You must be a very happy father :D

[graham.hobart]

Us mere mortals tremble at the hoof beats!
Amazing.
I don't know why I bother with my stuff when guys like you and Mike and Paul et al produce such stunning stuff..... Oh yeah-it's because I like it!
Great stuff. Like an APOD.
Congratulations
From cloudy hobart (again)
Graz:eyepop:

[astronobob]

1st class Image Rolf, absolutely breathtaking, ive also not seen this amount of structure revealed :eyepop:
Credits to your write-up too :thumbsup: puts a great new perspective on the Horse head through & through !
Awessomeness has been wacked up another notch :thumbsup:
Congratts with your gear and Image result.
Top Show :thumbsup:

[alistairsam]

Great stuff as always Rolf. Very nice details.
How dark are the skies at your place and do you bin rgb at all?
Have you thought of adding Ha detail as well?

Cheers
Alistair

[marco]

Excellent image in every aspect :thumbsup: I always admire the level of details you are able to achieve on your images, a great result indeed!

Cheers
Marco

[RickS]

Fantastic result, Rolf. You have injected new life into an old friend.

[cometcatcher]

Blimey. Looks like a hubble image. So much wispy detail in the dark regions.

[SkyViking]

Thanks Mike, good to know I've now earned that elusive badge of Astrophotographer :lol: Btw, I've heard of this 'Orion Nebula' which should be nearby, maybe now being a proper astrophotographer I need to have a go at it. :P

Re the pink colour yes it is indeed pink, although the emission from IC434 in particular is probably mostly red as I found the H beta emission in the blue frames to be very weak, much weaker than say the Eagle or other such nebulae. So on second thoughts I may have overdone the pink in my version, hard to know really. :shrug:

I probably tend to agree with you re the processing. I actually experimented quite a bit with this image, changing my work flow and tried some new things and learned a lot. The result might be a tad soft at high resolution, I'll see how the next one turns out :thumbsup:


Thank you Greg :)


Thanks very much Allan, I'm glad you liked it!


Thanks Rob, yes I'm certainly happy with the scope, there are no outstanding issues really. I've also just finished installing a homemade dewheater solution with Dewbuster controller - that was the last thing on my list. I'll probably post a thread with the details as it could be useful info for others.
Oh actually there is one minor issue remaining: I do need an extra Losmandy counterweight. I've temporarily beefed it up with a 6kg lead brick in a plastic bag rolled up and taped around the shaft in order to achieve optimal balance with the new OTA, but that hardly classifies as a permanent solution! :lol:


Thank you very much Graham, you're too kind :) It's all about enjoying it isn't it? That's surely my motivation too. I love the tinkering, experimenting, fine tuning and of course imaging and seeing the results. It's a great hobby.


Thank you Bob, very kind words indeed. I'm glad you found it interesting, I do try to add a bit of useful info to every subject I image.


Thanks Alistair, I have what I would probably call 'outer suburb' skies, with limiting visual magnitude around 5.5 on the best nights.
I used to bin RGB 2x2 but with the new scope I gather all data 1x1. This is because the brighter stars tend to saturate too much now with the larger aperture if binned 2x2, and it also gives me more flexibility having all data as 1x1. Another benefit is that I can create additional synthetic Luminance frames from the combined RGB data if I want to.
I don't have a Ha filter, but it's surely on my wish list. Would be good for Moonlit nights as well!


Thank you Marco, as you know I like squeezing every last bit out of the data! :thumbsup:


Thanks Rick, I'm glad I could entertain even with such a mainstream target :lol:

[dvj]

That is an A-class image. :eyepop:

I've never thought of the Horsehead itself casting a shadow in the foreground dust clouds. Guess I'll be getting rid of that Honders soon.

[Stevec35]

Top result Rolf!

Cheers

Steve

[alistairsam]

I've never thought of that either. you've brought out the dust details really well and the shadow really stands out. really cool especially from outer suburbs seeing. Was there any Light pollution to contend with?

Cheers
Alistair

[DJT]

Stunning picture, Rolf. Well done :eyepop:

[David Fitz-Henr]

Well done Rolf, a brilliant first image with your new scope! Nice colours and you have brought out a wealth of fine detail with 7 hours of luminance data :thumbsup::thumbsup: My only suggestion would be that there does appear to be some sharpening artefacts in some of the dim regions in the nebula, but a minor observation on a great image.

[iceman]

Stunning image, Rolf. Congratulations.

This is now IOTW (http://www.iceinspace.com.au).

[Paul Haese]

Nice work Rolf, Like I said on FB, there is plenty to like in this image. The full size image presents pretty well overall. Like the colour and detail. All these images of the Horse Head are making me impatient to finish the data collection for my image. Been months since I started, but I have a goal. Lovely work again Rolf. Top shelf.

[John Hothersall]

You've achieved great depth, the reflection neb has comes out extremely well, love the highlights on the horse. Very powerful image.

John.

[Rod771]

Fantastic image Rolf! Incredible detail in the Horse itself - amazing!

Well done :thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

[SkyViking]

Thanks John, you can send the Honders my way if you want, I can always use an extra finderscope :P:lol:
Seriously though, I love the efficiency and simplicity of a large Newtonian, and IMHO with a decent corrector they produce images rivalling any other system.


Thank you Steve, I just went for an easy target to stretch the wings of the new scope, but it did turn out nicely.


Cheers Alistair, yes that shadow caught my eye during processing so decided to show as much of the structures in the dust as I could.
Re light pollution, I have the light dome of Auckland to the NE where Orion was positioned during all the data gathering, so theoretically it will have interfered with the image, but I didn't notice any strong gradients or similar in the data.


Thanks David! :)


Glad you liked it David. It was a joy to play with the data and see what could be brought out. As mentioned earlier I did experiment with my processing flow and tried some new things, and the result probably shows some artefacts at full resolution. I plan to refine my technique so stay tuned :)


Thank you very much Mike, that's an honour! The new scope certainly passed the test :lol::thumbsup:


Thanks Paul, it was fun to try imaging this one as I've never done it before. I haven't even seen it visually although I have tried a couple of times but with no success. I suppose the new scope with its fresh coatings and larger aperture might give me a glimpse visually, I must try that.


Cheers John, I'm glad you liked NGC2023 too. Was it not for the Horsehead this would be a popular nebula in its own right, but alas it lies in the shadow of its more famous neighbour, literally! :lol:

[SkyViking]

Thank you Rod! :D

[Peter Ward]

What's not to like?

Beautiful optics. Excellent guiding.

I'm hard pushed to find any processing artifacts.

None really.

Stars are well resolved and tight (something you can only get with a long FL :thumbsup: ).

More data would smooth out the continuum, but so what.

A benchmark HH for sure :thumbsup::thumbsup:

[alpal]

Rolf,
Hi Rolf,
I had a look at all your pics & noted this one:
http://www.rolfolsenastrophotography.com/Category/125-inch-Serrurier-Truss/i-pnZShqQ/A

I can't quite understand how the guitar string collimation system works
& also why it doesn't cause multiple diffraction spikes?

The collimation you have achieved is obviously superb.
An RC or classical Cassegrain would have better spot sizes further off axis
but the KAF8300 is not such a large sensor where it would be apparent.

Still - I have learnt a lot from your thread about building this scope:
http://www.iceinspace.com.au/forum/showthread.php?t=98823&page=2

I am thinking of ideas on how to improve my own setup.

Congratulations on the IOTW.

cheers
Allan

[Octane]

What an outstanding image, my friend. :)

H

[marc4darkskies]

Yes indeed ... outstanding Rolf! :thumbsup::thumbsup: Congrats!

Cheers, Marcus

[SkyViking]

Thanks very much for the kind words Peter! I also expect improved seeing conditions once more settled weather rolls in here. So even higher resolution should be possible :D:thumbsup:


Hi Allan and thanks. There are 8 strings attached to the mirror holder and they are arranged in a cross like traditional spider vanes. You can (faintly) see how they line up in this image from the 10" :http://www.rolfolsenastrophotography.com/Category/Serrurier-truss-newtonian#!/i-HG6cQrr/O

Each string can be tightened/loosened via its own guitar tuner, so full positioning and orientation is easy to achieve for the secondary mirror. I have found it much easier than traditional spiders where you typically have to adjust with tools and go back to the eyepiece and check. Here I can turn the guitar tuners by hand while looking in the eyepiece to see the effect. It is also really easy to make careful micro adjustments which helps getting everything aligned optimally.

The two strings that make up each 'vane' don't have to overlap each other but just need to be parallel in order to appear as a single spike in the image, if that is what you mean. They of course also need to be parallel with the two strings on the corresponding opposite side, and overall this lineup can be tricky to achieve but once adjusted I don't have to touch it again since collimation is maintained by adjusting the primary, not the secondary.

Hope that helps :)

[SkyViking]

Thanks very much H, it's a classic target that never disappoints :) I'm glad to now have an image of it.


Thank you Marcus, it's good to be back in the game again with the new and larger scope finally finished.
Looking forward to your images with your new scope too :thumbsup:

[DavidNg]

The Horsehead is pretty detailed, like to color too.
Regards
David

[alpal]

Thanks Rolf,
I'm still getting my head around string spiders.
It seems difficult to set up - for advanced telescope makers only!
I will investigate it more & thanks for the photo.

cheers
Allan

[dutch2]

I never get sick of seeing the HH nebula
Wonderful image, lots of detail, just stunning.
:thumbsup::thumbsup:

[multiweb]

Great resolution in that shot Rolf. Congrat on IOTW. Well deserved. :thumbsup:

[kinetic]

Rolf,

what can I say,

brilliant...master class

Steve

[swannies1983]

Absolutely a cracker image!

[SkyViking]

Thank you David!


Thanks Ingrid, although I have never imaged the Horsehead before it has always been one of my favourite nebulae :)


Thanks very much Marc. I'm happy with the resolution from the new scope and there should even be room for improvement so it'll be interesting to see how the next images turn out, whatever the targets may be.


Thank you Steve, I'm glad you enjoyed it :)


Thanks Dan! :)

[DavidU]

Wow, that's amazing Rolf. well done.

[Shiraz]

beaut image Rolf - top shelf from the new kit. regards Ray

[ianB]

Looks like 3D in some parts, great photo, better than what I have seen in many publications.

[allan gould]

Almost missed this one. An exquisite image in all aspects and really never thought that the HH would throw a shadow until you pointed it out.
Remarkable.
Allan

[Nicola]

Very fine details there, congrats!

[Leonardo70]

Congrats ... one of the best i've seen of this.

All the best,
Leo

[Ross G]

An amazing photo of the Horse Head Rolf.

Probably the best I have seen!

Congratulations on IOTW

Ross.

[SkyViking]

Thanks very much David!


Thank you Ray, the new scope is working beautifully, I'm very happy with it.


Thanks Ian, the 3D effect was something I particularly wanted to bring out, glad you liked it.


Thanks a lot Allan. I haven't really heard that long shadow mentioned before either, but it's pretty obvious in deep images like this. It's such a cool nebula.


Thank you Nicola!


Thanks very much Leo!


Thank you Ross, I was happy to see so much detail in the data and it was great fun to try bringing it all out in the image.

[LucasB]

What a beautiful and very detailed photo. Great work Rolf.:thumbsup:
Lucas

[John K]

Fantastic image Rolf - I visited your web site as I was keen to see what is possible with a 12.5" Reflector and you really have set a benchmark there - excellent images!