Tiny Galaxy Spotted Halfway Across the Universe

Space.com

Astronomers have spotted and weighed a tiny galaxy located 6 billion light-years away, or nearly halfway across the universe.

Dubbed SDSSJ0737+3216, the just discovered galaxy is 100 times lighter than our own Milky Way and is the smallest galaxy ever identified at that distance. It is about half the size and approximately one-tenth the "weight" of typical small galaxies found closer to Earth.

The galactic lightweight was found using NASA's Hubble Space Telescope and the W.M. Keck Observatory in Hawaii. It was made visible by a phenomenon called gravity lensing, whereby light from a distant source is warped by the gravitational field of another massive object located directly in front of it.

What do they mean by "half way across the universe?" Do they mean half way across the "known" universe?

Anyways, I thought this was pretty cool. Perhaps it could help us learn how galaxies form, evolve and grow



[edit on 7-10-2007 by juicebox]

Originally posted by juicebox

What do they mean by "half way across the universe?"

Do they mean half way across the "known" universe?

Should be. The observable universe is at about 13 billion light-years across. So 6-billion light years sound about half-way.

Anyway, thanks for posting this

If the Universe truly is 13 billion years old and began from the "Big Bang," wouldn't that mean that the known universe is actually 26 billion light years across? As the light travels from the origin of the big bang for 13 billion years, it would cover 26 billion light years worth of distance, as a number line, from -13 billion, to +13 billion.

Also, the galaxy that was observed would be 6 billion years old, so it seems natural that it would contain less matter as there would still be much more loose matter floating around in the post-birth cosmos?

Either way, still extremely interesting that we are looking this far out there!

-Warlo

It seems I made a mistake earlier. The age of the Universe is about 13 billion years. But then taking into account red shift and the expanding universe, it appears that the observable universe is about 46 billion light years across.

Interesting wiki entry which may or may not explain things. (it partially did it for me..)

Observable universe

Originally posted by Beachcoma
It seems I made a mistake earlier. The age of the Universe is about 13 billion years. But then taking into account red shift and the expanding universe, it appears that the observable universe is about 46 billion light years across.

Hmm...didn't figure in the Hubble Expansion (get's out calculator). 46 billion light years, that's a lot of space.

Still wondering though...how exactly do you "weigh" a galaxy? Gonna have to do some looking on that one...

-Warlo

reply to post by Beachcoma



interesting (& perplexing) problem there...

since we can only 'observe' some ~13-14 billion light-years out in any direction...

then that is the observable size of the universe
the ~46 billion light-year model is an acadmic exercise, a model adapted to our comprehension.

for instance, a being living on a planet of that dwarf & light-weight galaxy
the scientists have discovered...would have the same ~13-14 billion-light-year horizon
that we presently have here on earth.
But their view of of their observable universe would include a volume of sky that would remain unseen from earth, because they are 6 bly distant
their 'horizon' would different in the direction exactly opposite the
earth-dwarf galaxy alignment

the new - "looking from above madel" - of the observable universe
from 2 points in space (here & there) would make the universe have the shape of an ellipse...some 52 billion light-years large, 'in theory'

but in practicality, the observable universe is only ~13-14 bly large, from any observation point at any one time


boggling!

mainstream science is such a joke.

[edit on 7-10-2007 by tobiascore]

Mod Note: One Line Post – Please Review This Link.

[edit on 7-10-2007 by Jbird]

Oh thanks Tobiascore for that completly useless remark, you get a gold star for effort.

Mod Note: One Line Post – Please Review This Link.

[edit on 7-10-2007 by Jbird]

Thanks everyone. Thank you Beachcoma for posting that link

It's amazing that we can see that far. The image that we see is really what the galaxy looked like 6 billion years ago, correct?

Well, they said it's a distorted image. This pic is from the link in the op:



Here's a better image from eurekalert.org:

The mass estimate for the galaxy, and the inference that many of its stars have only recently formed, is made possible by the combination of optical and near infrared images from the Hubble Space Telescope with longer wavelength images obtained with the Keck Telescope. “If the galaxy is representative of a larger population, it could be one of the building blocks of today’s spiral galaxies, or perhaps a progenitor of modern dwarf galaxies,” said Treu. “It does look remarkably similar to the smallest galaxies in the Virgo cluster, but is almost half the way across the universe.”

eurekalert.org

[edit on 7-10-2007 by juicebox]