Author Topic: nebula/ color  (Read 1258 times)

Brian Snyder

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nebula/ color
« on: December 24, 2017, 05:07:17 AM »
Do you ever see any color within nebulas if so which ones? ???



obenanus

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Re: nebula/ color
« Reply #1 on: December 24, 2017, 10:55:06 AM »
I have not.

Phil Barela

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Re: nebula/ color
« Reply #2 on: December 26, 2017, 11:35:03 PM »
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I have not.

 
So no reddish clouds or anything similar to that?  I just got a 8 inch have not had a chance to look at Any yet

ropnolini

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Re: nebula/ color
« Reply #3 on: December 27, 2017, 09:52:50 AM »
M42 (The Orion Nebula) is a frequent case of percieved color.  In smallish instruments and naked eye, there's absolutely no color to be viewed.  With medium instruments like a 3" to a 6", a strong blue color can be percieved.  With even bigger instruments such as a 8" to 12", you should start seeing more green and a little tinges of red.  With even more aperture the color begins getting richer.

It depends upon the nebula, but yes, with enough aperture, you can perceive color.  M42 is the primary object I see color on, but a few planetary nebulae give out a small sign of blue/green color.

Whatever you see in astroimages, that is not exactly what you see in the eyepiece (given your scope isn't monstrously enormous in aperture).
The reality is most DSOs will be grey (Which I'm personally fine with), unless you are able to obtain a gigantic aperture.  Look to stars and planets for color

akbrevecop

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Re: nebula/ color
« Reply #4 on: December 29, 2017, 10:57:42 PM »
In the 16", even in my location in Los Angeles, I see a very slight pink-rose coloration along the bright bar near the Trapezium in the Orion Nebula. When out at a dark site, I see greens, light blues and very light browns/tans as well, throughout the Orion Nebula. The "blue snowball" (NGC 7662) is indeed very blue-emerald in color, and the blinking planetary (NGC 6826) is nearly the same bluish color though muted; again both in the 16". Out in a very dark sky, my 80mm binocular shows the Orion nebula as a very (VERY) faint blue.

nepaletha

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Re: nebula/ color
« Reply #5 on: January 03, 2018, 07:01:50 PM »
I just bought the Orion xt8i

Tye Paez

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Re: nebula/ color
« Reply #6 on: January 10, 2018, 11:18:21 AM »
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I just bought the Orion xt8i

M42 will show blues and greens. With good enough conditions and dark skies, perhaps a sprinkle of red. Planetary nebulae will show muted blues and greens. Other than that, every other nebula is gray.

What's vital is obtaining access to a dark-sky site, driving down there, and using good quality optics. Then you must stay dark-adapted, and look in the eyepiece for quite some time to soak in all the details.

Luckily for you, M42 has just come into season, so you can see all the color you want.

Nathan Mayienda

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Re: nebula/ color
« Reply #7 on: January 10, 2018, 11:49:05 AM »
Are you using any filters? If not try an O-III or an NPB filter. It wont turn it into a picture you see from the Hubble, but it will help your views of gas nebulas.

Yung Pryor

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Re: nebula/ color
« Reply #8 on: January 11, 2018, 08:03:50 AM »
The Orion Nebula is incredibly colorful imo, in comparison to any other DSO i have seen. Ive seen several different color in the Orion Nebula. I’ve also green and orange in the ring nebula, with a 12 inch scope from a very dark site.

contiostetti

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Re: nebula/ color
« Reply #9 on: January 12, 2018, 02:17:53 AM »
A few inviolable laws of optics and vision as regards visual observation through an eyepiece (the afocal configuration) which I see are still frequently overlooked and/or misunderstood:

1) No telescope, however large, can deliver an image having surface brightness higher than seen by a smaller instrument or the unaided eye. Yes, you read that right. The eye alone actually delivers the brightest possible image of any extended object resolved as clearly larger than point-like. A telescope *only* delivers a bigger and more detailed image (and brings into visibility objects otherwise too small to register), it cannot magically boost image surface brightness.

A telescope actually provides a somewhat dimmer image simply because no optical system possesses 100% transmission efficiency.

2) A bigger image at the same--or even somewhat lower--surface brightness tends to *appear* brighter merely because of the larger area of the retina involved. More information derived from a larger image usually gives the very potent illusion both of increased brightness and contrast.

3) Image surface brightness is controlled not by the objective aperture, but rather by the exit pupil diameter. A 2" and a 20" aperture, both working at the same, say, 4mm exit pupil deliver the same surface brightness for DSO 'fuzzies' such as nebulae and galaxies, as well as the sky (which itself is the largest extended 'object.') The 10X larger image provided by the 20-incher is in *total* brightness 100X brighter than via the 2-incher because it occupies 100X more retinal area. But the unit area surface brightness is the same.

Maximum surface brightness occurs when the exit pupil is as large or larger than one's iris. Image surface brightness scales as the area of the exit pupil,vwhich is a squared function. A halving of the exit pupil results in a dimming of surface brightness (for *both* object and sky equally) by a factor of 4. Compared to a 7mm iris/exit pupil, a 1mm exit pupil makes the image 49 times, or just over 4 magnitudes dimmer.

Note, though, that point sources such as stars remain at the same total brightness; their aspect is not diminished in the way extended sources are because they remain as unresolved points. (But when getting into 'empty magnification', where a sub-1mm exit pupil is used, the resolved Airy disk now behaves as an extended object.)

4) The limit for color detection is 18-19 magnitudes per square arcsecond (MPSAS). If an object is not at least this bright (in surface brightness), NO telescope can overcome this limitation.

Objects at or not much brighter than this threshold will exhibit no perceptible color until magnified on the retina sufficiently. This is where a larger aperture comes to the fore. A small scope that cannot magnify sufficiently without going to a smaller exit pupil and hence dimming the image too much is no aid. A bigger scope can deliver a suitably sized image at a larger exit pupil and hence of higher surface brightness.

5) Our eyes are *at best* about 1/10 as sensitive to red H-alpha as for the blue-green H-beta and O-III emission lines. When dark adapted, this ratio is nearer to a factor of 20!

6) Only 2 or 3 emission nebulae are bright enough for the red H-alpha to be glimpsed. Those remaining nebulae bright enough to reveal color will exhibit a green or blue-green hue.

No reflection nebula has sufficient surface brightness for color to be seen.

7) The brightest nebulae have peak surface brightness of about 14 MPSAS. This is 4-5 magnitudes, or 40-100X brighter than a 17 MPSAS city or full Moon-lit sky. Such nebulae, clearly, can punch through strong sky glow and have their color seen; no need for a country-dark sky for these guys.

8) Galaxies and globular star clusters often have central core surface brightness in the 15-17 MPSAS range. But the subtle yellowish hue typical for these old stellar systems is mighty subtle and hence not readily perceived.

vuicapathvie

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Re: nebula/ color
« Reply #10 on: January 12, 2018, 07:34:38 AM »
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The Orion Nebula is incredibly colorful imo with a 12 inch scope. Ive seen all sorts of color in the Orion Nebula. I’ve also green and orange in the ring nebula, with a 12 inch scope.

Your color vision must be much more sensitive than most people's.

I have never seen colors in the Ring, though I do see many of the more intense planetary nebulae as strikingly bluish or greenish. NGC 2392, the Eskimo, in Gemini, is a good example.

As for the Orion Nebula, I see a subtle but pretty obvious pastel green in modest-sized scopes. In big scopes, the Huygenian region has reddish veins. Very striking, though still quite subtle.

I've never seen color in any other emission nebula.

Jack Hillian

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Re: nebula/ color
« Reply #11 on: January 13, 2018, 01:32:14 AM »
The only nebulous object I have observed has been M42. With my 10 inch Newt, I can perceive a VERY faint greenish tint, but mostly grey. My youngest son, at 24 yrs of age, can also detect some blueish color and he says he can see a slight bit of pinkish, reddish hint of coloration. I envy him...

Clear skies!

CB

Mortimer Concepcion

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Re: nebula/ color
« Reply #12 on: January 13, 2018, 07:20:11 AM »
If you're expecting the kind of color you see in pictures, forget about it right now. You won't.

You can see some coloration in nebulae of the very highest surface brightness. For me, the most obvious colors I've seen in nebulae have been blues and greensin some small intense planetary nebulae... the Saturn Nebula NGC 7009, the Eskimo Nebula NGC2392, and one in Hercules whose number escapes me may have been the most colorful of all. I've never spotted reds in nebulae... the human eye is much less sensitive to red than green.

Mortimer Concepcion

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Re: nebula/ color
« Reply #13 on: January 14, 2018, 12:39:53 AM »
Quote
Quote

The Orion Nebula is incredibly colorful imo with a 12 inch scope. Ive seen all sorts of color in the Orion Nebula. I’ve also green and orange in the ring nebula, with a 12 inch scope.

Your color vision must be much more sensitive than most people's.

I have never seen colors in the Ring, though I do see many of the more intense planetary nebulae as strikingly bluish or greenish. NGC 2392, the Eskimo, in Gemini, is a good example.

As for the Orion Nebula, I see a subtle but pretty obvious pastel green in modest-sized scopes. In big scopes, the Huygenian region has reddish veins. Very striking, though still quite subtle.

I've never seen color in any other emission nebula.
Thinking back on this, I think maybe my post was poorly worded.
Incredibly colorful, in terms of any other deep sky object i have seen, is what I should have said.
I also am pretty skeptical the accuracy of our memories, but i remember seeing enough color the first time seeing the Orion nebula through my scope that I went on CN and raved about it.
I think the colors that I was seeing, were pink, red, orange and were honestly pretty dim and difficult to make out, but were present.
The conditions were excellent as well, and I spent a long time in the dark probably a big factor as well.
The ring nebula, I definitely saw green at a very dark site in the middle of nowhere Idaho, and I felt confident I was starting to see some orange color at the edge.
Who knows though maybe my eyes\mind were playing tricks on me.

Its pretty amazing seeing color, but its pretty faint, and that in no way means that objects that have no color visible arent incredible. I personally find significant detail, like the structure and folds of the Orion nebula, detail and structure visible in galaxies and details i can readily make out in any object, more impressive then dim color, and I think many would agree.

guizietropid

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Re: nebula/ color
« Reply #14 on: January 15, 2018, 10:32:53 PM »
I blame the Orion Nebula for getting me into this.
I got interested after sitting out and shooting pictures to make Star Trails.
Then I set up my spotting scope and one night, there it was! Tiny, but I could make out some color in it.
I spent the next month debating with myself about buying a telescope, and did I really think I could take pictures of objects in space.
Orion won and I slid down the slope into Astrophotography.
I spent 3 more months grooming 'Wish Lists' toward the goal of getting images of DSO (deep space objects) and specifically Nebula.

One thing to note is that the human eye reports what it immediately sees to the brain, but it cannot build up the Photons coming in from space like a digital camera, or the old film cameras, could do.
So visual observing has those Human limitations.