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APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 5:08 am
by APOD Robot
Image M42: The Great Orion Nebula

Explanation: Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula. The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Many of the filamentary structures visible in the featured image are actually shock waves - fronts where fast moving material encounters slow moving gas. The Orion Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our Galaxy as the Sun. The Great Nebula in Orion can be found with the unaided eye just below and to the left of the easily identifiable belt of three stars in the popular constellation Orion. The featured image, taken last month, shows a two-hour exposure of the nebula in three colors. The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years.

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Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 9:57 am
by heehaw
Looks like abstract art!

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 10:54 am
by Boomer12k
What can you say but....WOW.... my favorite DSO....here are TWO shots from a few nights ago with my new Meade 8" LX 90 and my Celestron Evolution 6" ....not quite as spectacular...but closer up...just the Trapezium area....

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Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 10:59 am
by Boomer12k
At this angle...as I look at "The Running Man Nebula"...it looks like a WOMAN, sitting with a child in her lap.... but the child looks like EMPEROR PALPATINE!!!!!! Thought he died on the Death Star 2....hmmmmm...

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Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 11:01 am
by Boomer12k
You could almost call The Great Nebula...."The Pierced Heart Nebula"...it looks like a heart shape, and is being pierced from the lower left....

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Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 12:47 pm
by Ann
Boomer12k wrote:What can you say but....WOW.... my favorite DSO....here are TWO shots from a few nights ago with my new Meade 8" LX 90 and my Celestron Evolution 6" ....not quite as spectacular...but closer up...just the Trapezium area....

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Glad to see your Orion Nebula pictures, Boomer! :D

When I observed the Trapezium region through a telescope, the nebulosity looked almost exactly as it does in your top picture. Perhaps it was a tad greener. The ridge wasn't red, but its color was different from the rest of the nebula.

Great to see "Trapezium region through a telescope" revisited! :D

Ann

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 4:36 pm
by BobStein-VisiBone
I've always thought of this nebula as Orion's Kneecap

Image

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 5:33 pm
by pgp566
Sorry but this is horribly over processed; how did such a wretched image get on to APOD? This is what M42 actually looks like, in natural RGB colours:
http://www.astrocruise.com/milky_way/M42_0712.jpg

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 6:03 pm
by Chris Peterson
pgp566 wrote:Sorry but this is horribly over processed; how did such a wretched image get on to APOD? This is what M42 actually looks like, in natural RGB colours:
http://www.astrocruise.com/milky_way/M42_0712.jpg
In natural colors, M42 looks gray. Any image that shows color is unnatural.

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 6:35 pm
by pgp566
[quote=In natural colors, M42 looks gray. Any image that shows color is unnatural.[/quote]
Perhaps to the naked eye, but using _any_ imaging device (which accumulates light) you'd have to grossly under-expose to get M42 to look grey . M42 has _very_ strong emissions in Ha and OIII, and a very large amount of broadband light. Going right back to film days, any correctly exposed, correctly filtered, RGB image will most certainly show colours. If in doubt why not try it?

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Wed Nov 29, 2017 6:41 pm
by Chris Peterson
pgp566 wrote:
In natural colors, M42 looks gray. Any image that shows color is unnatural.
Perhaps to the naked eye, but using _any_ imaging device (which accumulates light) you'd have to grossly under-expose to get M42 to look grey . M42 has _very_ strong emissions in Ha and OIII, and a very large amount of broadband light. Going right back to film days, any correctly exposed, correctly filtered, RGB image will most certainly show colours. If in doubt why not try it?
An imaging device means you don't have natural color.

In an image, the color represented is useful for telling us about the physical properties of that thing. It isn't very useful for describing what is "natural". Film, of course, is even worse than digital for representing colors.

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Thu Nov 30, 2017 9:31 pm
by Visual_Astronomer
Gotta agree with Chris on this. Color is created in the brain. When I look at M42, even through a big scope, it's "natural color" remains grey.

Re: APOD: M42: The Great Orion Nebula (2017 Nov 29)

Posted: Thu Nov 30, 2017 11:10 pm
by geckzilla
You all are too caught up on colors. They're not what give it the over-processed look. It's all the high pass filters and localized value adjustments that flatten out the nebula to a nearly uniform brightness everywhere in an effort to make the faintest parts just as bright as the brightest parts.