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Very Large Telescope Captures New 27-Megapixel Deep Field
Posted by
Soulskill
on Sun Nov 09, 2008 09:22 AM
from the awesome dept.
from the awesome dept.
xyz writes "European Southern Observatory's Very Large Telescope has captured the deepest ground based U-band image of the universe yet. The image contains more than 27 million pixels and is the result of 55 hours of observations with the VIMOS instrument. 'Galaxies were detected that are a billion times fainter than the unaided eye can see and over a range of colours not directly observable by the eye. This deep image has been essential to the discovery of a large number of new galaxies that are so far away that they are seen as they were when the Universe was only 2 billion years old.'"
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Hmm... (Score:5, Funny)
Oh my god. It's full of pixels!
Re: (Score:2, Informative)
not all at once, 78.6MB file could cause the slashdot effect
Re:Hmm... (Score:4, Interesting)
What's the deal with TIFF anyways? I convert that 80mb file losslessly to PNG, and it brings it down to 47mb. Almost 50%!
Parent
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Shortages? (Score:4, Insightful)
Re:Shortages? (Score:4, Insightful)
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Time (Score:5, Insightful)
And here I am wasting it on Slashdot
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Re: (Score:2, Insightful)
It's the same principle as ever, when awestruck in the face of beauty: "you can look, but you cannot touch".
That thought process... (Score:2)
It's exactly that thought process which leads to running out of (or destroying) resources.
That's what they said on Easter Island... (Score:3, Insightful)
And that's what most of the world is saying today.
80 MB TIFF (Score:4, Insightful)
Seriously, Slashdot, pointing to an article that contains a link to the 80 MB TIFF image at full resolution. Feeling a bit sadistic today, are we? Oh well, I'm rather early so I clicked it nonetheless. Feeling like a bit of a egocentric sadist myself today.
It works without a hitch in the AlternaTIFF TIFF Image Viewer. You can clearly see the galaxies, but otherwise it is a large sheet of colored dots (as expected I suppose).
Re:80 MB TIFF (Score:4, Interesting)
don't feel sorry for them... feel sorry for the poor schmucks that actually CLICK on the image link and expect their browser to render it before the wheels grind to a halt.
Parent
Fantastic (Score:2, Insightful)
Context vs Hubble Deep Field (Score:5, Interesting)
Just to give a sense of perspective in case you read the title and went so what?
Re: (Score:3, Interesting)
And how fast are we moving relative to the source of the big bang?
All points equally in the entire universe are "the source of the big bang". The big bang isn't just the origin point for all matter, it's the origin point for the entire universe and all space and time. If you want to "see" the big bang, or as close as we can see, look at the CMB [wikipedia.org].
Only 27 megapixels? (Score:2)
Considering that there are commercial cameras [wired.com] on the market that have resolutions of 50+ megapixels for "just" $40,000 (not much for professional scientists or astronomers). It seems like a fairly simple thing to modify for use in the UV spectrum (maybe that's the part we are supposed to be impressed with?).
Perhaps they meant gigapixels?
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then one has to wonder why they bothered mentioning it...is there no way to measure the capability of optics, if that is what is important?
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Filament-like structures (Score:2)
What are these?
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I see a duckie
and a vase
and a cow rendered in an obscure encryption method
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How much area does this cover? (Score:5, Interesting)
Yeah, I know..... a lot....
What I mean is, if I look up in the sky, how big of a patch of the sky does this picture cover? The size of the full moon? Bigger? Smaller than a grain of sand at arms length?
Re:How much area does this cover? (Score:5, Informative)
The image is 14.1 x 26.1 arcminutes according to ESO website. For reference, the moon is about 30 arcminutes.
Parent
Re:How much area does this cover? (Score:4, Informative)
I think you, like a lot of people, have wildly overestimated the angular diameter of the full moon. It's about 30 arcminutes (0.5 degrees). It's a lot smaller than you think. It's one of the first things we were told in my astrophysics lectures, and it's stuck with me.
An angle of 0.5 degrees at arms length (~70cm) gives you approximately 70cm * tan(0.5 degrees) = 6.1mm (i.e. a circle of paper 6.1mm in diameter held 70cm from your eye would 'cover' the full moon). Try it.
3cm at arms length equates to an angle of about 2.5 degrees.
Parent
Re: (Score:3, Interesting)
I just tried it by holding a ruler at arms length up at the moon. The moon isn't quite full tonight, but it's pretty close, so I can guesstimate where the rest of it is from the curvature of what's there.
I found the moon to be about 1.2cm with the ruler held at arms length - about twice what you're suggesting. Perhaps I have very short arms?
I don't dispute your maths, but I would like to know where the discrepancy in my experimental evidence is coming from...
"Very Large Telescope" (Score:5, Funny)
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At least they didn't follow the Wisker's cat food advert and call it the 'largest *ever* telescope'.
Yeah, short-sighted names bug me too.
Coverage by Bad Astronomer here (Score:5, Informative)
Phil Plait has quite a bit to say about this image:
http://blogs.discovermagazine.com/badastronomy/2008/11/07/voyaging-deep-into-the-universe/ [discovermagazine.com]
"Scanning the full-res image is incredible. There's so much to see! Each dot, each smudge, is a full-blown galaxy, a collection of billions of stars. They're very, very far away; some of these galaxies are estimated to be 10 billion light years distant; you're seeing them as they were just a couple of billion years after the Universe itself began, and the faintest are one-billionth as bright as objects you can see with your own eye."
He also talks quite a bit about his favorite astronomical event - gamma-ray bursts.
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So we're just a motion-capture system away from the Total Perspective Vortex...
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Actually, for perspective, this image is approximately 1/500000th of the sky.
According to my calculations (Score:2, Interesting)
errors in the calculations, and fixes: (Score:4, Informative)
Some corrections, because the GP confused linear and solid angles:
14 linear arcminutes * 21 linear arcminutes = 294 sqare arcminutes
1 square degree = (60 linear arcminutes)^2 = 3600 sqare arcminutes
294 square arcminutes / 3600 sqare arcminutes ~= .08167 square degrees
there are ~41253 square degrees in a sphere, only this fraction of a sphere is subtended by the picture:
(294 square arcminutes) / (41253 square degrees) ~= 1.980*10^-6
As someone stated elsewhere, this is about 1/500,000 of the sky (i.e. the celestial sphere).
So we count the number of galaxies encountered in this secion, then divide by the fraction subtended; using GP's estimate:
16,800 / (1.980*10^-6) gives ~8.49*10^9 galaxies
However, about 2 orders of magnitude more galaxies are in the field, though only ~16,800 galaxies are detected in this particular image of the field. The number of galaxies in the *observable* universe is at least on the order of 100 billion (10^11), per other, more sensitive surveys with more rigorous counting methods than a quick subsampling as performed by a human examining an image visually.
Next:
...with an average of 40 billion stars in a galaxy...
This is lower than I've encountered. The average galactic mass is about 100 billion solar masses, and the average stellar mass is about .5 solar masses*, so the the average number of stars in a galaxy is is on the order of 100~200 billion.
...it is conjectured that there are some very small galaxies, making the average much smaller than our own Milky Way...
Actually, it is fairly well established that there are indeed many such "small" galaxies. But though the number of "extremely large" (trillions to tens of trillions, versus hundred billions for the Milky Way) galaxies is small, the contribution to the mean ("average") number of stars per galaxy is disproportionately large because they themselves are disproportionately large. This is the nature of the arithmetic mean: a few highly weighted outliers skew the mean more than the median, and the median more than the mode. That's precisely why the "average" number of stars per galaxy is actually on the order of the Milky Way.
(* Note that the "average" stellar mass is skewed upward by the few but extremely massive stars just as galactic mass is. A "typical" star is smaller than the .5-solar mass "average" star; the vast majority of stars are smallish red dwarfs, with the sun being more massive than at least ~90% of stars, if only by a little in the range of stellar masses from ~.04 to ~150.)
So:
~(10^11 galaxies) * ~(10^11 stars/galaxy) = ~10^22 stars
The highest *reasonable* estimates I've seen yield a little over 5*10^22 stars, so on the order of 10^23 stars is still conceivable.
Parent
Determined nominatively? (Score:3, Interesting)
Did anyone notice the name of the press officer?
Dr. Henri Boffin.
Nominative determinism [wikipedia.org] in action.
Re:Determined nominatively? (Score:5, Funny)
Parent
Re:article image (Score:4, Informative)
The second link provides a 78MB TIFF (and a more modest but same-resolution 30MB JPEG) image.
Parent
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Oh cool I didn't see those links
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I don't know about your system, but with mine all I have to do is mouse over the pic to see the pointer change into a little hand. Tells me there is a link.
Re:article image (Score:5, Informative)
However, it's a dinky low-resolution image one could have captured with a CCTV camera. Come on, you can do better than that.
I'm sorry, but what? The second link in the story has links to 6480 x 4236 JPGs and TIFs, which calculates to 27MP, the file sizes are 31MB and 79MB, respectively.
Normally, I would agree that web stories normally fall short with photos and multimedia, but it's just not true here.
Parent
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Is it just me or is that 76mb tif sadly lacking in quality? Looks like a lossy jpeg. Here's something off the cuff from my wallpapers folder, redstar [vftp.net] that has more detail and is under 1mb.
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If an image is sharp, then you weren't pushing the limits of the instrument in the first place.
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I'm guessing you missed the link that was included [eso.org] in both the slashdot summary and the article!
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How about just filtering any post that uses a lot of big words yet has indications of brain damage like abbreviating every other "and" to "&" (or "you" to "u")?
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I wouldn't know - I never take a bath.
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Refraction flares caused by the crystalline pattern of molecules in the glass of the lenses.
Um, no. The spikes are caused by the diffraction of light around the struts supporting the secondary mirror in the telescope. The wave nature of light ensures that no matter how large you build your telescope, you cannot focues stars to a perfect point.