Peeking Through Orion's Dust

[SkyViking (Rolf)]

Hi All,

Here is my latest image, an infrared view of the Orion Nebula. Thanks to the NIR filter I was able to grab this even though the bright Moon was high in the sky.

Link to large image (2.45MB)

About the image:
Traditional images of the Orion Nebula taken in visible light primarily display the familiar and striking magenta colour from H-Alpha emission, as well as large dark obscuring clouds of dust. But infrared light penetrates these clouds better and allows for a peek deep into the heart of the nebula, revealing complex details and hundreds of bright young stars that are otherwise completely invisible.
These stars shine primarily in the infrared and appear as golden red in this image. Only a minority of these are even visible in traditional images.
The infrared region seems largely unexplored by amateur astronomers. But using a filter that only allows infrared light (>700nm) to pass through allows obtaining an image of these hidden features. Effectively the band observed is 700-1100nm since the sillicon CCD chip is not responsive to wavelengths longer than that, and this band is called NIR (Near Infrared).
One issue arising from this technique is that the NIR band does not have a colour as such, since it lies outside the visible light spectrum. So I thought for a while about how to best produce a colour image that whould emphasize the NIR data. I decided to substitute the R channel with NIR which nicely brings out the contrast between the nebula itself and all the young obscured stars that shine primarily in infrared.
I used a NIR filter together with G and B filters to create this colour composite. The resulting images were assigned to the different channels as NIR->Luminance, NIR->Red, G->Green and B->Blue.
The CCD sensor (KAF-8300) is no where near as sensitive in the NIR band as it is in visible light so I gathered a lot longer exposure time in NIR than in G an B. Still, the Orion Nebula is so bright that overall integration time was just 1 hour and 21 minutes.
The Orion Nebula lies 1350 light-years away in the constellation Orion and is the closest stellar factory to us. Here new stars are born out of the dense clouds of gas and dust. The nebula is lit up by the four bright young stars in the centre called the Trapezium. These stars form a small cluster and many more are in fact present, as can be seen in this infrared view.

Image details:
Date: 24th and 27th November 2012
Exposure: NIR(Luminance) 72m, NIR(red) 72m, G(green) 4.5m, B(blue) 4.5m, total 1hr 21mins @ -30C
Telescope: 10" Serrurier Truss Newtonian f/5
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

Hope you enjoy this unorthodox view of the Orion Nebula. Comments and critique is welcome as always,

Regards.
Rolf

[tilbrook@rbe.ne (Justin Tilbrook)]

Great image Rolf!

Never seen orion like this before, very interesting to see the stars pop out of that mass of nebulosity.

Cheers,

Justin.

[multiweb (Marc)]

Great shot and assorted blurb. Always something new and interesting to show.

[CoolhandJo (Paul)]

nice - colours lovely

[Stevec35 (Steve)]

Nicely done Rolf. I always find IR images interesting. I did M42 with my IR filters a while back but I think your rendition is more aesthetically pleasing than mine. Good write-up too.

My NIR M42 is here:

http://members.pcug.org.au/~stevec/M42_IR_STL11K_RC.htm

Cheers

Steve

[ourkind (Carlos)]

I thoroughly enjoyed the writeup and your image, APOD for sure! Thank you so much for sharing it.

If I may ask, are all the red stars within the nebula or withinANDbehind at varying distances across our galaxy. Is it possible with your gear and longer exposures to also capture galaxies behind these obscuring dust clouds?

[RickS (Rick)]

Very interesting view, Rolf!

[cometcatcher (Kevin)]

Fascinating image. I always like to see different views of old favourites.

[Larryp (Laurie)]

Very nice-certainly a different take on it!

[strongmanmike (Michael)]

Great shot Rolf, like Steve C's it's a slightly different perspective, love all the stars.

Had another surf of your web site while I was looking at this image, it's a great collection you are massing mate.

The 12.5" is looking great too

MIke

[SkyViking (Rolf)]

Originally Posted by tilbrook@rbe.ne

Great image Rolf!

Never seen orion like this before, very interesting to see the stars pop out of that mass of nebulosity.

Cheers,

Justin.

Thank you Justin I was surprised by the amount of hidden stars too, it was fascinating to see how they pop out compared to a visual image.

Originally Posted by multiweb

Great shot and assorted blurb. Always something new and interesting to show.

Thank you Marc, I'm glad you enjoyed it

Originally Posted by CoolhandJo

nice - colours lovely

Thanks Paul, I worked quite a bit to achieve a sensible combine that would highlight the NIR details while preserving some pleasing colours.

Originally Posted by Stevec35

Nicely done Rolf. I always find IR images interesting. I did M42 with my IR filters a while back but I think your rendition is more aesthetically pleasing than mine. Good write-up too.

My NIR M42 is here:

http://members.pcug.org.au/~stevec/M42_IR_STL11K_RC.htm

Cheers

Steve

Thanks Steve, that's a great shot of the core you've got there. The seeing was not super when I took this so I didn't make a large crop of the Trapezium area, but it's on the bucket list

Originally Posted by ourkind

I thoroughly enjoyed the writeup and your image, APOD for sure! Thank you so much for sharing it.

If I may ask, are all the red stars within the nebula or withinANDbehind at varying distances across our galaxy. Is it possible with your gear and longer exposures to also capture galaxies behind these obscuring dust clouds?

Thank you Carlos The golden/red stars are mostly confied to the nebula, but I suppose some are slightly in front and others slightly behind, in relation to the centre. They are probably all recently condensed out of the core area and share proper motion so cannot have wandered too far off yet I assume.
Capturing galaxies behind the nebula might be tricky, but some might be poking through in the outskirts given long enough exposure.

Originally Posted by RickS

Very interesting view, Rolf!

Thank you Rick

Originally Posted by cometcatcher

Fascinating image. I always like to see different views of old favourites.

Thanks Kevin, yes it's always fun to put a new angle on these things.

Originally Posted by Larryp

Very nice-certainly a different take on it!

Thank you Larry, I was surprised by how different and yet very familiar it looks, glad you liked it

Originally Posted by strongmanmike

Great shot Rolf, like Steve C's it's a slightly different perspective, love all the stars.

Had another surf of your web site while I was looking at this image, it's a great collection you are massing mate.

The 12.5" is looking great too

MIke

Thanks very much for your kind words Mike. The 12.5" build is going well (I've recently updated the build thread) and I'm looking forward to the final result. Hopefully the mirror will get here in Jan/Feb, so not too far off now!

[Ross G]

Amazing view Rolf.

Something different.....Thank you.


Ross.

[Paul Haese]

Unique view and impressive looking image Rolf. Once again you have taken us through another view not normally seen.

[madbadgalaxyman (Robert)]

What a remarkable concentration of stars is revealed in this uncommonly interesting image!

I am not sure whether the overall large-scale concentration of stars behind the nebula is actually a star cluster or an association; stellar associations are defined as being gravitationally unbound groups (overdensities) of stars which have a common physical origin (associations of stars are therefore expected to disperse rapidly)

I wonder to what extent the apparent (observed) two-dimensional density of stars falls off, just outside of Rolf's frame?

The Orion Nebula Star Cluster is a recognized star cluster that is plainly revealed in infrared images, but I have no info yet as to the angular size of the bound star cluster

[SkyViking (Rolf)]

Originally Posted by Ross G

Amazing view Rolf.

Something different.....Thank you.


Ross.

Originally Posted by Paul Haese

Unique view and impressive looking image Rolf. Once again you have taken us through another view not normally seen.

Thank you very much Ross and Paul, it's always fun to view things in a different light - literally!

Originally Posted by madbadgalaxyman

What a remarkable concentration of stars is revealed in this uncommonly interesting image!

I am not sure whether the overall large-scale concentration of stars behind the nebula is actually a star cluster or an association; stellar associations are defined as being gravitationally unbound groups (overdensities) of stars which have a common physical origin (associations of stars are therefore expected to disperse rapidly)

I wonder to what extent the apparent (observed) two-dimensional density of stars falls off, just outside of Rolf's frame?

The Orion Nebula Star Cluster is a recognized star cluster that is plainly revealed in infrared images, but I have no info yet as to the angular size of the bound star cluster

Thanks for your informative comments Robert, much appreciated. I would like to eventually do a mosaic of this area in NIR and see what shows up. Something on the todo-list!

[venus (Lydia)]

So many stars great image...
yours Steve too