Wow, Ive never seen M42 like this.

[Stonius (Markus)]

Stumbled across this amazing image of the Orion Nebula here

Check out all that dusty goodness!

Markus

[dimithri86 (Dimithri)]

Mind blowing

[Retrograde (Pete)]

Yes amazing. Very similar depth to (although a wider field than) this Malin Award winning image by IIS member Paul Haese: http://www.iceinspace.com.au/forum/s...d.php?t=118119

[Stonius (Markus)]

Interesting to note that the dust lane between M42 and NGC 1977 looks like it is being gently illuminated by M42 itself, though it is not the typical blue of a reflection nebula. I wonder what the difference is?

[ZeroID (Brent)]

Originally Posted by Stonius

Interesting to note that the dust lane between M42 and NGC 1977 looks like it is being gently illuminated by M42 itself, though it is not the typical blue of a reflection nebula. I wonder what the difference is?

Depends on how he processed it. It's a bit over the top for me. just a personal thing. I like it a bit more natural and softer although I have to say I'm impressed with the amount of detail he has pulled out of it. I imagine there is a lot of exposure time invested in it.

[Stonius (Markus)]

I think there's a spectrum. At one end you have an image that depicts pretty much what you'd see visually. At the other, you have the sort of detail that can only be brought out by the special techniques of astrophotography and post processing.

Most lie somewhere on that spectrum I guess. I think this example is notable because it lies so far on the heavily processed end of the spectrum. I find the extra details fascinating. I love to imagine the 3-dimensional structure of nebulea and the extra details given here only add to my enjoyment of what I can already see with my eye.

By way of contrast, I was looking for a good shot of the Tarantula nebula recently, to examine some details I'd seen when observing. But they were all so heavily processed for the 'beauty shot' that the dust lane I was looking for was all but invisible in most because it had been processed out of existence!

-Markus

[Stonius (Markus)]

Originally Posted by Stonius

Interesting to note that the dust lane between M42 and NGC 1977 looks like it is being gently illuminated by M42 itself, though it is not the typical blue of a reflection nebula. I wonder what the difference is?

It's a curious thing - a reflection nebula is typically blue, Supposedly because as the light travels through the dust cloud it absorbs the red end of the spectrum more.

This relies on the light source being embedded in the cloud (ie, Pleiades) which is not the case here. If the light comes from outside the cloud and is reflected back off the surface of the cloud (as in the photo), is it still called a reflection nebula? The point being, we can see the dust cloud because it is reflecting light, rather than obscuring / absorbing it, which is the typical idea of a dust cloud (ie, coal sack).

To extend upon that idea, is any dust cloud potentially a reflection nebula if you expose long enough?

Confused.

Markus

[ZeroID (Brent)]

Remember, a 'cloud' is not a solid object. Light transmission, illumination through the cloud which is made up of microscopic particles or molecules even will colour the result.
And the colour is whatever the imager liked at the time. Try playing with the hue controls in any imaging software, you can make anything you like.

[Stonius (Markus)]

Thanks Brent. What I'm trying to ask (albeit with a poorly worded question) is whether it's still classified as a reflection nebula if it's not hazy and blue. And if it is, where does the distinction lie?

As an analogy - compare the sun shining on bright puffly clouds with headlights shining through fog. The latter is the standard reflection nebula. The former is what I assume is going on in the photograph (externally lit puffy clouds).

-Markus