Slashdot Mirror
New Galactic Neighbor
Dan Yocum writes "The Sloan Digital Sky Survey reveals a new Milky Way neighbor: a galaxy so big we couldn't see it before. A huge but very faint structure, containing hundreds of thousands of stars spread over an area nearly 5,000 times the size of a full moon, has been discovered and mapped by astronomers of the Sloan Digital Sky Survey."
Can't see the galaxy for the stars, eh?
Great minds think alike; fools seldom differ.
"What happens if a black hole eats another black hole?"
It becomes Congress?
--- Grow a pair, liberals... stop letting the Republicans bully you!
Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.
Could this be what's warping the Milky Way, previously thought to be Dark Matter?
Why is it that when you believe something it's an opinion, but when I believe something it's a manifesto?
Windows in 6 Bytes (IA-32) : 90 90 90 90 CD 19
It's a trap!!!!
Quite frankly this is the kind of science that the Hubble cannot do. For one, the Hubble is designed for a finer spatial clarity, hence its field of view is so tiny that surveying the entire sky would literally takes decades (if not a century).
This work instead shows how invaluable ground observatories (esp the small ones) are. It's not a super-flashy job; it's a long, time-consuming, and slow-rewarding job. But once you've done it, you get your 15 minutes of fame (actually, in this case, you may make it into the history book).
"spread over an area nearly 5,000 times the size of a full moon,"
.5 degree
Interesting wording.
So that must mean 5000 full moons in the sky?
Moon = 1800 arc seconds
or 1800/60 = 30 arc minutes.
or 30/60 =
So what is that in degree of sky?
A fist at arms length is roughly 10 degrees.
I was a graduate student at the Astrophysical Sciences deptarment at Princeton when they were planning and starting to build the SDSS. A few interesting facts:
Some very clever optics (designed by James Gunn) went into the telescope. Normal telescopes do not produce the large field of view required. There were existing specialized telescopes which did (Schmidt cameras) but they have the imaging plane in the wrong place.
The main camera uses 30 2k x 2k CCDs, cooled by liquid nitrogen. At the time (early '90s) these cost on the order of $200k per chip.
The camera works in "drift scan" mode: the telescope moves such that the images of the stars drift along the columns of detectors in the CCDs. The packets of charge are shifted along the CCDs at the same rate - so instead of producing distinct individual frames, it continuously outputs data along an ever-lengthening strip along the sky. As I recall, the data rate is about 8Mbyte/s.
The camera spends rather more time on spectroscopy than imaging. (The imaging is primarily about selecting targets for the spectroscopy.) The spectrograph does 640 objects at a time. A computer-drilled plate is (manually) plugged with fibre optic cables in the right positions for that field of sky.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
I wonder where he got 3d glasses that make stuff look 3d in real life? I could use some of them to stop walking into walls so much!
Ah, a parliament or congress.
We've been here a while now. We did the Veni, Vidi, Vici thing, you just don't know it yet, but, yea, all your base are belong to us.
Well, now we know. Little did we know that we knew all along.
And the brethren went away edified.
That's right. It's a dwarf galaxy because its actual size is small (compared to other galaxies) but its apparent size is 5,000 times that of the Full Moon because it's so close, as galaxies go.
In case that's not enough to explain it to you, consider that the Moon is much smaller than Jupiter, but appears to be larger because it's much nearer.
Good, inexpensive web hosting
What's the humidity inside your room? It's not completely dry, right? So, why don't you see a white patchy cloud in your room? Not even in summers?
Why?
Well, it has to do with the density. Even if there is a galaxy nearby, if the content of a galaxy is sparcely populated by ordinary stars (and they are, I RTFA), you ain't gonna see them. Just like you don't see "humidity" (water molecules) in your room.
Actually, things at that distance are far less 3D to your eyes than the molecules making up the things in the picture on a flat piece of paper on the table in front of you.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
This is like that part in the movie or the comic book, where the guy is tripping out or whatever, and he's staring into the dark void of space, and then slowly he realizes he's staring into a GIANT FUCKING EYE!
Computers are useless. They can only give you answers.
-- Pablo Picasso
"before they invade us,"
Optimistic, aren't you?
Even worse, if you consider that we are the aliens, and our species has simply invaded and conquered this planet an aen ago. We adapted, survived, and destroyed our own history. If you don't understand the destroyed part of that, go to a library and read some 6,000 year old books. Assuming you knew the language, you wouldn't find the books. They're lost, damaged, and/or intentionally destroyed over the years.
We are the aliens, and our brothern have forgotten about us. We will be stuck here, alone, for a long time.
Serious? Seriousness is well above my pay grade.
Black hole collisions are theoretically possible, and has been simulated on a Cray
Yes, this is offtopic, but what is really wild is that they simulated that in 1994 on a Cray C90, which has a floating point speed of 16 gigaflops. Back here in 2006: the Playstation 3, a TOY, has a floating point speed of 2 teraflops.
Sounds an awful lot like witchcraft, if you ask me. I think we should burn you and the moon, just to be sure.
You better watch out, there may be dogs about . .
They know you're lying when you tell them "You can't see it because it's so big".
Actually, on an intergalactic scale, this thing is freakishly close. According to TFA this dwarf galaxy is 30,000 light years from Earth. The distance from Earth to the center of the Milky Way galaxy is roughly 27,700 light years (according to Wikipedia). This thing is nearly right on top of us.
BTW, if you're preparing to shoot it, the quote you're looking for is "It's coming right for us!"
Apparently they're now called vertically challenged galaxy overlords.
Think of the little people...