Starship Asterisk*

geckzilla wrote:Sure, but they are mixed with all the pure wavelengths so only with careful filtering and processing does it come out looking so vibrant. Any wideband images of glowing gas tend to be rather drab. Anyway, I don't think there is any way to explain it in a way that is easy to understand.

geckzilla wrote:Ot's also important to know that these colors are representative. The wavelengths coming out of the gas are not pure enough to have such vivid colors.

Rusty Brown in Cda wrote:Can anyone explain why the sky in the background is blue instead of the usual black?

rstevenson wrote:

Freemind wrote:Who's to say the pillars are not living creatures except people whose minds are dwarfed through lack of imagination, which, Einstein said, was more important than knowledge.

So you're starting a conversation by saying that anyone who disagrees with the idea that "the pillars are ... living creatures" has a mind "dwarfed through lack of imagination"? It's going to be a very short conversation.

Rob

Freemind wrote:Who's to say the pillars are not living creatures except people whose minds are dwarfed through lack of imagination, which, Einstein said, was more important than knowledge.

Rules For wrote:But when I look through a telescope at the Moon, it seems both larger and brighter...?

JohnD wrote:You mean like the one from NASA, published in todays Guardian and linked to in my posts above?
John

another poster wrote:

I'm actually putting together a visible + IR image

It's already done: here.

I'm actually putting together a visible + IR image

WickedLad wrote:

geckzilla wrote:

WickedLad wrote:I've often wondered as I look at APOD photos whether the apparent light and shadows are what my eyes tell me they are. (And the "Pillars of Creation" seem the most extreme example.) Are there really bright light sources where they appear to be, in this case, behind and above the subject structure? Do they really cast what look like shadows in the photo? Are there no bright light sources in front of or below the structure to cast light where there those shadows appear?

What you are actually seeing is a complex set of glowing gases. Instead of thinking of what you see as light and shadows coming from the nearby stars, think of the structures themselves glowing gently. There are shadows in a sense because the energy of the stars is what is causing the gas to be energized and emit light so places where the gas does not receive enough energy are not glowing or are glowing more dimly.

Very interesting! Thank you, Geck!

Rules For wrote:But when I look through a telescope at the Moon, it seems both larger and brighter...?

Chris Peterson wrote:But our eyes? No. It doesn't matter how big a telescope you use, what you see will never be brighter than your naked eye sees the same thing. Only larger.

Rules For wrote:But wouldn't we see the color emerge through a sufficiently long-exposure photograph? And if so, couldn't we theoretically (though impractically!) also see the color if only we could look through a sufficiently enormous telescope that was able to collect and concentrate enough photons at once?

Chris Peterson wrote:Indeed, this is true for all nebulas. None can appear to our eyes as anything other than a vague grayish fog with bit of subtle structure visible (think of the Milky Way). Doesn't matter where we observe from, or what kind of purely optical instruments we use. These things are all extremely dim.

Visual_Astronomer wrote:Narrow-band filters, color-mapping and other manipulations allow one to create beautiful works of art, but I constantly have to explain to people that there is no vantage point out in space where you could actually see a scene like this with your eye.

Chris Peterson wrote:

geckzilla wrote:[What you are actually seeing is a complex set of glowing gases. Instead of thinking of what you see as light and shadows coming from the nearby stars, think of the structures themselves glowing gently. There are shadows in a sense because the energy of the stars is what is causing the gas to be energized and emit light so places where the gas does not receive enough energy are not glowing or are glowing more dimly.

I'd say that the dominant thing we are seeing is dust structures, not glowing gases. The dust structures are directly illuminated by stars, and are also seen against a background of ionized gas. The dust casts shadows. I think it's perfectly proper to say that we're seeing light and shadows from nearby stars, just that most of it is stimulated, not reflected or scattered.

Chris Peterson wrote:
Maybe not. When you follow the Fast Facts link for this image it suggests (strongly) otherwise. But I think that the little image at the bottom describes what they're actually trying to say. Badly. Very, very badly.

About this Image

This image is a composite of separate exposures acquired by the WFC3 instrument on the Hubble Space Telescope. Several filters were used to sample and narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are:

Code: Select all

WFC3/UVIS Image of M16

     F502N ([O III]) 	    blue
     F657N (Hα + [N II]) 	green
     F673N ([S II]) 	     red

Chris Peterson wrote:

geckzilla wrote:I find the image at the bottom says it perfectly. This press release includes not one but two new images. The fast facts page very clearly states what colors were assigned to each filter for each image even without the picture to help explain.

Yeah, once you figure it out you can tell what they're trying to say. But it's extremely unclear. One of the worst written explanations I've encountered.

blastoff wrote:Is it possible to see any movement over the 25 year interval (a mere instant indeed) at this scale? of the gasses themselves or perspective shift as we float by? my guess is not much. We'll simply have to take a photo every twenty five years for the next several million, and have a pretty amazing time-lapse!

geckzilla wrote:I find the image at the bottom says it perfectly. This press release includes not one but two new images. The fast facts page very clearly states what colors were assigned to each filter for each image even without the picture to help explain.