LDN1622 - Dark nebula in Orion

[pietervdv]

Hello all,

 

Long time without a post...

Last week I captured some photons for this 2 panel mosaic of LDN 1622, a dark nebula against a backdrop of Barnard's loop in Orion.

I captured 17 hours worth of exposures during 3 freezing nights. Platesolving, focusing & mount flip was automated with SGP.

 

CCD: SBig st-8300 -30°C (30 minute subframes)

Filter: Astrodon 5nm h-alpha

Scope: Homemade 10" f/3.8 Astrograph with Wynne corrector

Mount: Mesu 200

 

Very minimal post processing (10 min max): Calibrated with flat frames, stretched and mosaic assembly in PS.

 

Thanks for checking it out!

Regards,

Pieter

Edited December 3, 2016 by pietervdv
Typo

[PatrickGilliland]

Super work Pieter - some lovely detail in the dark tendrils.  Well done.  Paddy

[Pompey Monkey]

That is super! It really has a 3-D feel to it. The pin-point focus is impressive too.

If you don't mind, I'll borrow your image and do a plate-solve on it to see if it's worth a stab with my modest 400 mm fl

Also, I run my STF 8300m at -20 C, even in the winter. Does it really make a huge difference to the dark current by going to -30?

[Barry-Wilson]

Very good mono image Pieter.  Are you planning to capture RGB?

[swag72]

I love this and its on my list for this year  Absolutely gorgeous

[RichLD]

Excellent capture and processing (minimal or not) of a very beautiful object that works extremely well for me in mono - your framing is spot on mate, top work! 

 

[Rodd]

Didn't know a reflection nebula would look so stunning in Ha.  Where did you get the material for that home made scope?  Is it worth a try?  Did you grind/polish the mirror or did you get that done?  

 

Rodd

[ollypenrice]

Delicacy, finesse and originality! What more could we ask for?

Olly

[pietervdv]

Thanks for the generous comments! It is a very nice object that deserves some more attention I reckon!

 

4 hours ago, Pompey Monkey said:

That is super! It really has a 3-D feel to it. The pin-point focus is impressive too.

If you don't mind, I'll borrow your image and do a plate-solve on it to see if it's worth a stab with my modest 400 mm fl

Also, I run my STF 8300m at -20 C, even in the winter. Does it really make a huge difference to the dark current by going to -30?

A shorter focal length should work great, if framed carefully you could include the bright band of Barnard's loop.

Concerning the CCD cooling, the added effect is probably minimal. But the st-8300 is such a noisy camera every bit helps.

 

3 hours ago, Barry-Wilson said:

Very good mono image Pieter.  Are you planning to capture RGB?

No colour I'm afraid, I only image in b&w. Well technically speaking, it is partly RGB since this is the Red channel.

 

1 hour ago, Rodd said:

Didn't know a reflection nebula would look so stunning in Ha.  Where did you get the material for that home made scope?  Is it worth a try?  Did you grind/polish the mirror or did you get that done?  

 

Rodd

I don't believe this is a reflection nebula? I could be wrong, but it's a dark nebula obscuring the hydrogen emission of Barnard's loop. The parts of the scope came from all around, kind of hard to put in 2 sentences. I tweaked and tinkered on the thing for 3 years before I was 100% satisfied. If you like a challenge, go for it I would say! I did not make the mirror myself, Orion Optics made it for me.

 

Pieter

 

[CraigT82]

Superb image! Can I ask, what it is the creates the 'stripey' diffraction spikes? I often see it on images from professional observatories but not often on amateur images. I expect the answer will go way over my head. 

[Pompey Monkey]

2 hours ago, CraigT82 said:

Superb image! Can I ask, what it is the creates the 'stripey' diffraction spikes? I often see it on images from professional observatories but not often on amateur images. I expect the answer will go way over my head. 

Constructive/destructive interference in in the light as it recombines after diffracting around the spider arms. Think about Young's "double-slit experiment" (Google it if you are not familiar). It only shows up in narrow band images where  light is filtered to an almost coherent source.

Broadband light (LRGB) is made up of a continuous spectrum and it all gets smeared into a continuous spike where the phases of different wavelengths of light recombine incoherently.

HTH.

[CraigT82]

Yes I think I understand!  Thanks for he explanation Paul.  

[RichLD]

12 hours ago, Pompey Monkey said:

Constructive/destructive interference in in the light as it recombines after diffracting around the spider arms. Think about Young's "double-slit experiment" (Google it if you are not familiar). It only shows up in narrow band images where  light is filtered to an almost coherent source.

Broadband light (LRGB) is made up of a continuous spectrum and it all gets smeared into a continuous spike where the phases of different wavelengths of light recombine incoherently.

HTH.

Thanks PM, now I know why my Bahtinov mask diffraction spikes are stripey when using NB filters 

[Rodd]

Not to be a stick in the mud, but slight graininess would disappear with a very small amount of noise control.  

[astrocatinfo]

Amazing detail and image Pieter. Really long exposure. Well done!!

 

Edited December 6, 2016 by astrocatinfo