Nebulae

[peter]

If you go over to wikipedia and type in the word 'Nebulae' the resulting search brings up astrophotographic images of the most staggering beauty and delicacy. The very first two on the page alone (the so called 'Pillars of Creation' and the 'Triangulum Emission Garren Nebula') are enough to take your breath away when you enlarge them to the size of the full screen. Now what I want to know is this. If you were able to see these actual nebulae from a much closer vantage point in space with the naked eye, would all those colours that lend the photographic images such incredible beauty still be there - or are they colours that are only introduced to the photographic image but not truly visible to the human eye were it able to view the nebulae directly. If the colors are 'artificial' are they so by virtue of screening out certain wavelengths of light so that only certain other coloured ones remain to be seen, or is it by adding false colour - as if you were covering the colour of the metal of a car's body by spraying colour on to it's surface. Does anyone know the answer to this. (Nb. there is a follow up to this that is dependant on the answer to the above - but that will have to wait for a while.)
(ps. If anybody wants to add a link to the page please feel free to do so - I have no idea how this is done!)

[Lord Zombiac]

hmmm. Recently viewed nebulae at a star party in white sands. Some of these modest telescopes produce images nearing hubble quality.
Colors seemed pretty much the same.
Saw a cool globular cluster too.
My own refractor lost the tripod and the got stolen.
My reflector couldn't resolve anything until recently, and now the bushings are so worn out that you can't keep the bloody thing stable enough to find anything.
By far, the best thing I ever viewed was Saturn occulted by the moon.

[peter]

Hi LZ. Very jealous that you have gotten to see some of these things for yourself through telescopes. If I'm right a telescope on it's own is just bringing that distant object closer, not altering it's apearence as such - and so the implication of what you have seen is that the nebulae do indeed display these colours of themselves. re the globular cluster - is that a cluster of galaxies or stars. Or indeed can the term refer to either type (if both types do exist).
I've seen Haleys Comet, Hale-Bop (of course), but beyond doubt best of all, the Total Eclipse of the Sun seen in the UK at the end of the Millenium. God, that was just unreal!

[CovenantJr]

A year or two ago, Lurch posted a link to Astronomy Picture of the Day in the little-used Haven Farm area of Kevin's Watch. There are some breathtaking pictures there. kevinswatch.ihugny.com/phpBB2/viewtopic.php?t=15726

(ps. If anybody wants to add a link to the page please feel free to do so - I have no idea how this is done!)

Certainly: en.wikipedia.org/wiki/Nebulae

[lurch]

to answer the question...no..color is assigned to elements..that is to say..sulfur= yellow..red= hydrogen..etc etc..This assignment of color to element is arbitrary..Hydrogen could be green or blue,,it matters little as long as no other element is assigned the same color.

As delicate as things may appear...please remember you are looking a structures that are as little as 5 LIGHT YEARS across to things hundreds of LIGHT YEARS across (galaxies for example). So delicate has to be also connected to Massive.

[Lord Zombiac]

Ah Peter! I'm the one who's jealous!
I've never seen a total eclipse. My first chance to see one is April 2024 in my old home town, Austin Texas...
If it is rainy or overcast I will probably never see one!
Some say that the coincidence of our moon being exactly the right size for a total eclipse, as opposed to an annular, is the factor from which the human's great curiosity for knowledge sprung.
A globular cluster is a collection of stars, too small to be a galaxy. They are often found just outside of galaxies, and sometimes have an astonishingly even distribution of stars, forming a "globe."

[Vraith]

with the naked eye, would all those colours that lend the photographic images such incredible beauty still be there - or are they colours that are only introduced to the photographic image but not truly visible to the human eye were it able to view the nebulae directly. If the colors are 'artificial' are they so by virtue of screening out certain wavelengths of light so that only certain other coloured ones remain to be seen, or is it by adding false colour - as if you were covering the colour of the metal of a car's body by spraying colour on to it's surface. Does anyone know the answer to this. (Nb. there is a follow up to this that is dependant on the answer to the above - but that will have to wait for a while.)
(ps. If anybody wants to add a link to the page please feel free to do so - I have no idea how this is done!)

Lurch's answer is correct, colors are assigned...it brings out details, too, to do this. But also, don't be misled about your naked eye question if you were closer, or used a telescope [those two won't match each other, either, telescope everything would be redder compared to closer]...they wouldn't be the same colors, but you might see a misty cloud of singular color, or white, or spotty, or wisps, or swaths of colors, or bands or splotches, or lots of things depending on which elements are present, whether they're distributed basically uniformly, or with concentrations, and how much energy is in the system [hydrogen can emit 4 widely spaced and distinct colors across the spectrum, depending on energy...iron has at least 10x more, IIRC, some widely spaced distinct, some clumped together in slight variations of same color. [when I say distinct here, I mean distinct to the human eye...to the scientist, every one is an exact wavelenth, and every element can only emit certain exact wavelengths and not others.]

[lurch]

I have a 16 inch light bucket. Once beyond the planets, and besides the stars, the only color seen thru that telescope using any of the eye pieces I have,,is a haunting green tinge in the heart of the Orion Nebula and some faint color in various planetary nebulea, but not all. Galaxy cores seem to show different hints of off white to faint yellow. Even molecular clouds around very large stars can reflect hints of color of the nearby star. But,,in most cases,,besides the planets and stars..the color of a web based or printed image of something out of this world,,is applied by man.

Take a pic of the Eagle Nebula with a filter in front of the lens that only allows wavelength 10 thru. Say wavelength 10 is the wavelength of sulfur. Resulting pic will have many shades ( concentrations) of sulfur, from brite to dim. Same pic with wl filter 20,,then 30..etc. Then stack the pics together making one pic out of all of them....Taa DAA!...Heck,,amateurs are even doing this these days..thats how good the equipment is getting in the " digital era".

[Avatar]

Loresraat?

--A

[peter]

Thanks a million Guys for these postings. I was kind of hoping that all those fantastic 'disney' colors were out there waiting to be seen by anyone looking out of the window of a passing spaceship but in my heart I knew this was naive. That the colors are 'assigned' does not reduce the beauty of the objects - in some sense it furthur enhances their mystery in that their profound complexity must be translated into a simpler (ie visual) form in order for us to even glimpse it's existence.

LZ, 2024 is a long time to wait my friend, but will be worth every day of it. I waited maybe 10 years for the one that occured where I live from first hearing it was going to happen. I was mortified on the day because the weather was overcast and grey and their seemed no hope whatsoever of viewing the eclipse itself. Only my wife's prompting got me into the car and out to a local clifftop where hundreds had gathered. I had heard that on occasion it has been known for the 'clouds to part' prior to totality even in the worst conditions but put this down mainly to wishful thinking. But I swear to you the impossible happened. Minutes before totality the clouds broke appart and we saw the whole event in it's entierity. It is an odd, etherial, amazingly profound experience. The diamond ring is simply the most beautiful thing I have ever seen! I know now why people follow eclipses all over the world and why hardened scientists break down and weep in the face of this, simply the Greatest Show on Earth.

(Covenant Jr. - Many thanks for posting the link)

[Starfire 152]

Peter

For this I have come.

Most Nebulae appear grey or pale green in the telescope. Our eyes are not sensitive enought to see the colors. In low light we dont see color. Cameras are much more sensitive and easily capture detail and color invisible to the eye. Many of the photos released by NASA are colored and processed for aesthetic impact. Look on the telescope box in the store and you see those color photos. People actually expect to see that!

There are video cameras available that can give a live color image when used with a telescope. These are becoming popular. But not cheap.

Stars have a variety of colors. To most folks thay all appear white. In the scope they appear bluish, yellow, orange or red with many shades and hues of these. The deep red stars are the best but rare.

Juoiter is the most colorful planet, followed by Mars and Saturn. The Moon has colors also, but these are subtle.

Whats really neat is that if you're viewing a galaxy in a telescope, the light from that galaxy may have traveled for 20 million years. You see that galaxy as it was 20 million years ago. Light from the Sun is only 8 minutes old. Distance has no meaning to such power.

You can buy a good telescope for under $500 but not from any box store. Give it a try.

[peter]

Thanks starfire 152 - and welcome to the Watch by the way. Yes, it's interesting that light thing where we only ever see a picture of the past due to the time it takes the light to get to us. Let me just stay with that and ask this question. The universe is what, 15 billion or so years old. Thus any light that has been traveling for 15 billion years to get to us pretty much started at the begining of the universe (and will bring a picture of what was going on in the universe at that time with it). That light must by definition have travelled a distance of 15 billion light years ( since a light year is the distance light will travel in one year). Does it then follow (and this is where my reasoning sort of breaks down) that the 'edge of the universe' is 15 billion light years away from us - or is it just that that is the furthest distance our telescopes will ever be able to see because the light would not have had time enough to travel to us from any distance further away than that (this seems the more likely of the two to me). And how do we deal with the problem that the universe must be the same age all over it - so therefor if the first was true then every point in the universe would be 15 billion light years from the edge and thus every point in the universe, no matter where it was would be at the center. And none of this explains how something that is supposed to be expanding and thus MUST have an edge is also supossed to be infinite and therefor can't! AAARRRGGGHHHHH!!!

[Starfire 152]

The question you pose is one of Cosmology. We have not seen light from anything more than a few billion lights years away, yet. The nice photos are of things very "close" to us, on a cosmological scale.

We can no more "see" the edge of the universe than point our finger in the direction of the fourth dimension. The universe does not have a boundary by its very nature, and if it did, it would be impossible to discern. Its the expansion. The further away something is, the faster its moving away from us.

The big question is: Will the universe keep expanding, or eventually contract? Or how did it begin, and how will it end? This is the basis of all philosophy.

I reccomend googling the Cosmic Background Radiation (COBE), Hubble Constant, or reading the works of Michio Kaku for better answers.

To avoid headaches, I much prefer the simple joys of the constellations and things I can see myself.

[dANdeLION]

This is a cool thread. It might fit better in the Loresraat, though.

[peter]

To avoid headaches, I much prefer the simple joys of the constellations and things I can see myself.

This I agree is the best take. Just one more 'toe dip' into the realms of potential headache stuff though - I recently saw a program on the nature of reality where a leading physisist was proposing the idea that the three dimensional experience of our reality could in fact be the equivalent of a hologram of information encoded at the two dimensional 'edge' of our universe (apparently the idea springs from the problem of how information is 'conserved' when matter et al passes into a black hole). This is an odd idea to get your head around and has all sorts of weird 'who encoded the information at the edge' conotations about it, but apparently the mathematics of the idea work and so it has to be taken seriously. Who Knows..... I think I'll just keep looking at the pictures

_____ , by all means shift this to the Loresraat if that is it's true home (though I would hang my head in shame for it to be seen among some of the exhaulted matereal there!) By the way should I be the one to shift it - I have no idea if non-moderators or tech-geeks (ie us ones that just contribute posts rather than oversee and controll the Watch) can do stuff like that. If so I will need to be led very slowly through the proceedure like a child taking his first tentative steps through the park. Trust me - you do not want me gamboling about like a bull in a china shop in the tech stuff of the Watch (not if you want it to continue in it's present seamless way that is. Be carefull of your answer ____, the Watch trembles on the very edge of Chaos.

[Vraith]

The question you pose is one of Cosmology. We have not seen light from anything more than a few billion lights years away, yet. The nice photos are of things very "close" to us, on a cosmological scale.

Fairly recently, I ran across a blurb about a picture [not what you'd call high quality] of the furthest/oldest so far...13.1billion, within the first billion years of the universe.

And peter, there's a thread about that hologram stuff around somewhere...pretty strange stuff.

[aliantha]

_____ , by all means shift this to the Loresraat if that is it's true home (though I would hang my head in shame for it to be seen among some of the exhaulted matereal there!) By the way should I be the one to shift it - I have no idea if non-moderators or tech-geeks (ie us ones that just contribute posts rather than oversee and controll the Watch) can do stuff like that. If so I will need to be led very slowly through the proceedure like a child taking his first tentative steps through the park. Trust me - you do not want me gamboling about like a bull in a china shop in the tech stuff of the Watch (not if you want it to continue in it's present seamless way that is. Be carefull of your answer ____, the Watch trembles on the very edge of Chaos.

___ has no power here.

(Mods can only do the housekeeping stuff in their own forums. Only admins can play around with that stuff in *every* forum.)

Anyway...I'll move this now.

[stonemaybe]

Thanks a million Guys for these postings. I was kind of hoping that all those fantastic 'disney' colors were out there waiting to be seen by anyone looking out of the window of a passing spaceship but in my heart I knew this was naive. That the colors are 'assigned' does not reduce the beauty of the objects - in some sense it furthur enhances their mystery in that their profound complexity must be translated into a simpler (ie visual) form in order for us to even glimpse it's existence.

LZ, 2024 is a long time to wait my friend, but will be worth every day of it. I waited maybe 10 years for the one that occured where I live from first hearing it was going to happen. I was mortified on the day because the weather was overcast and grey and their seemed no hope whatsoever of viewing the eclipse itself. Only my wife's prompting got me into the car and out to a local clifftop where hundreds had gathered. I had heard that on occasion it has been known for the 'clouds to part' prior to totality even in the worst conditions but put this down mainly to wishful thinking. But I swear to you the impossible happened. Minutes before totality the clouds broke appart and we saw the whole event in it's entierity. It is an odd, etherial, amazingly profound experience. The diamond ring is simply the most beautiful thing I have ever seen! I know now why people follow eclipses all over the world and why hardened scientists break down and weep in the face of this, simply the Greatest Show on Earth.

(Covenant Jr. - Many thanks for posting the link)

I went down to Devon for this, to be in the area of totality. The clouds did not break where I was, but it was still the most stunning experience of my life. To see a wave of darkness flowing over the landscape towards you, to be sitting in a field just after 10AM and it is as dark as night, then to see the darkness roll away from you.

I envy your diamond ring, but I still wouldn't swap it for my experience!

[wayfriend]

Some new pictures of the Helix Nebula out today.



It's also called "A Big Damn Eye Nebula."