Andromeda Galaxy 3 Times Bigger than Thought

Professur

Professur

Well-Known Member
MINNEAPOLIS, MN – We know less about our nearest galactic neighbor than thought, astronomers announced today. A map of the outer suburbs of the Andromeda galaxy finds that its rotating disk of stars is three times bigger than previously measured.

The Andromeda galaxy is a spiral galaxy similar to our own Milky Way. Although there are smaller dwarf galaxies nearer to us, Andromeda is the closest large galaxy – at about 2 million light-years from Earth. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).

Under dark skies, Andromeda can be seen by the naked eye as a large fuzzy blob.

3 times bigger

Scott Chapman from the California Institute of Technology presented the results of a survey of Andromeda's stellar motions here at the 206th Meeting of the American Astronomical Society.

"What we have done is measured the radial velocity of stars in the outer regions – basically, how fast they are moving towards us or away from us," Chapman said during a press conference this morning.

Chapman was one of a team of astronomers using the Keck telescope to measure speeds of 5,000 stars in the outskirts of Andromeda. They were surprised to find that these suburban stars were actually rotating as if they were part of the galaxy's disk. Their paths had been expected to be more random.

"Finding all these stars in an orderly rotation was the last explanation anyone would think of," Chapman said.

The implication is that the disk is 220,000 light years in diameter, instead of the earlier estimates of 70,000 to 80,000 light years. In our sky, that means Andromeda stretches out over the length of 12 full Moons.

This periphery of Andromeda is faint – it accounts for about 10 percent of the light from the galaxy. Still, there are millions of stars presumably orbiting in this outer region

A bizarre fossil record

By looking at separate components of a galaxy one can try to piece together how the galaxy built up over time. The central region of a spiral galaxy is believed to have formed first, with the rotating disk coming later. The type and orbit of stars in certain regions provides a kind of fossil record for the evolutionary history.

Andromeda is an "ideal laboratory" because it is so close, and yet it is outside our galaxy.

"It is very hard to study this evolution in our own galaxy because we are stuck in the middle of it," Chapman said.

And yet this laboratory is full of puzzles as to how it came to be. Besides Andromeda's new size, the researchers are scratching their heads over the fact that the outer rotating stars are arranged into about 20 identifiable clumps. This would imply that they formed out of the merger of smaller galaxies with the main galaxy.

But rotating disks and clumps are not compatible in galaxy formation models.


"This giant disk discovery will be hard to reconcile with computer simulations of forming galaxies," said Rodrigo Ibata of the Observatoire Astronomique de Strasbourg in France. "You just don't get giant rotating disks from the accretion of small galaxy fragments."

Chapman said that if a merger is the correct explanation, it would have had to occur relatively recently – within the last 200 million years. Otherwise, the clumps should have been "washed out." We may, therefore, being viewing our big neighbor at a rare moment in its history – right after it has gobbled up one of its little neighbors.
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Source

So, science knows all, eh? The closest major galaxy, and they think they were only wrong by 300%. Yeah, that really afirms my faith in their red shift/dark matter theories. Hey, dumbass. Maybe the reason you had to reinvent "the ether" is because you're an idiot.
 
tommyj27

tommyj27

Not really Banned
very interesting. i didn't know andromeda was so close to the milky way, relative to it's size.

why is minneapolis the dateline for the article though? i don't see the connection, unless space.com is MN-based.
 
Luis G

Luis G

<i><b>Problemator</b></i>
Staff member
So we know that Andromeda was roughly 2 million light years away, by the figures of the article it is now at ONLY 1.95 million light years away.

Watch out, we might collide :D
 
Luis G

Luis G

<i><b>Problemator</b></i>
Staff member
A few years ago they said Andromeda and Milky Way were getting far away from each other. :shrug:
 
SouthernN'Proud

SouthernN'Proud

Southern Discomfort
All I can say is, thank God for the exactness of science, which by its nature explains everything.

Maybe they can carbon date it and figure it out...that seems to be their explanation for everything else they claim to know and are wrong about.
 
Luis G

Luis G

<i><b>Problemator</b></i>
Staff member
SouthernN'Proud said:
All I can say is, thank God for the exactness of science, which by its nature explains everything.

Maybe they can carbon date it and figure it out...that seems to be their explanation for everything else they claim to know and are wrong about.
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Science does not claim to be right about anything unless there is irrefutable proof, everything else are just theories, speculations and experimental results and should be taken as such.

The greatness of science is its ability to adapt itself and ACCEPT new knowledge as time passes by and new models and theories are proposed that explain with greater accuracy a given phenomena.
 
SouthernN'Proud

SouthernN'Proud

Southern Discomfort
In other words, the nifty license to say, "Well, we thought we knew...we said we knew...but we were wrong. Now THIS time, we're right. Absolutely. No doubt about it, we nailed it this time."

Must be nice.
 
Luis G

Luis G

<i><b>Problemator</b></i>
Staff member
SouthernN'Proud said:
In other words, the nifty license to say, "Well, we thought we knew...we said we knew...but we were wrong. Now THIS time, we're right. Absolutely. No doubt about it, we nailed it this time."
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No "we thought we were in the right direction, but we have found that this works better, and with all certainty we will find something that works better".

That's science man, what you posted is just pseudo-science crap and you should stop reading that or simply ignore it 'cause it is no better than religions and mediums.
 
Gonz

Gonz

molṑn labé
Staff member
Luis G said:
The greatness of science is its ability to adapt itself and ACCEPT new knowledge as time passes by and new models and theories are proposed that explain with greater accuracy a given phenomena.
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Theory, at best.
 
Luis G

Luis G

<i><b>Problemator</b></i>
Staff member
Gonz said:
Theory, at best.
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Yes, but from time to time some people discover theorems, which are mathematically irrefutable and will ALWAYS work under the specified circumstances.

But I do grant that science also has a belief system, the more clear exponent of this beliefs are axioms, which you just assume to be true (like 2+2 = 4).
 
Gonz

Gonz

molṑn labé
Staff member
Just as soon as those who absolutely believe in religion quit balking at science & those that absolutely believe in science quit balking at religion, the theory may progress. Until then, everybody is wrong & damnit, we're gonna prove it.
 
chcr

chcr

Too cute for words
Luis G said:
Yes, but from time to time some people discover theorems, which are mathematically irrefutable and will ALWAYS work under the specified circumstances.

But I do grant that science also has a belief system, the more clear exponent of this beliefs are axioms, which you just assume to be true (like 2+2 = 4).
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Ahh, but science wants to know why two and two are four as well. It's not enough to know that 2+2=4 (BTW, do you know why?). Science postulates that there is always an explanation regardless of whether or not you understand it.

IMO, religion holds that some things are simply unknowable while science holds that simply not knowing something in no way implies that it is unknowable. Science does not necessarily preclude religion, but the reverse is not true.
 
Luis G

Luis G

<i><b>Problemator</b></i>
Staff member
chcr said:
Ahh, but science wants to know why two and two are four as well. It's not enough to know that 2+2=4 (BTW, do you know why?).
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I do not know why, it think it is just one of those evident truths or axiom. Do you know why?
 
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