Ring Of Stars Found Around Milky Way

LoPingHo writes "Scientists have found a ring of stars around our galaxy that has previously been undetected due to the faintness of the stars. The article says that it only amounts to 1% of the galaxies mass, but if they are just now finding those, that means there could be even fainter ones there too. Could this be part of the elusive 'dark matter' talked about so much lately?"

Comments

Ring of stars

[CaseyB]

Sounds like they've discovered a Kemplerer Rosette. :)

I don't get it

[Cyno]

Isn't dark matter simply matter that doesn't emit light? If stars get formed by huge clouds of gas that eventually create so much heat and pressure that it starts a process of fusion, then its more than likely all this dark matter we are talking about is just that, dark matter, dirt, whatever you want to call it. It isn't anything significant other than it isn't radioactive, which is a good thing, IMO.

Re:I don't get it

[zmooc]

Before you say it, yes its impossible to accelerate to lightspeed.

Only according to a theory that assumes c is a constant while it is not - it's getting slower al the time. It's called CDK. This may also very well mean the red-shift calculations used to determine the speed at which galaxies move away from us are totally wrong which may therefore mean that the universe is not expanding at all (or at least not that fast) which makes the mass-calculations bullshit as well and may very well mean dark mass does not exist and there's just nothing out there. This is a good read about it: http://www.ldolphin.org/bowden.html

Re:What if it's the other way around?

[merlin_jim]

In the article: "If the ring turns out to be due to a satellite galaxy, it would mean that we are seeing the Milky Way cannibalizing a small galaxy and incorporating it into the galactic disk..." But what if it's the other way around?

Wouldn't that be like the researcher who, several years ago, proposed the theory that The Odyssey was not written by Homer the blind poet but was in fact written by a completely different blind poet named Homer?

Re:short answer

[merlin_jim]

Could this be part of the elusive 'dark matter' talked about so much lately?

Yes.

Most scientists believe that dark matter makes up 80 - 95% of the total gravitational mass of the galaxy, and probably the universe.

Dark matter is simply the term given to matter that we haven't observed yet, except indirectly through its gravitational effect.

This is certainly some portion of the dark matter. But I wouldn't say a significant part, or even a part really worth mentioning. While the dark matter is almost definitely comprised of several different sources, it seems certain to me that there is an entire class of gravitational objects that we have yet to observe, and this is the cause of the dark matter. Whether its dark stars, black holes, heavy neutrinos, or some even more strange and cosmic form of matter I don't know. It could be all of those and more.

Point being, if the dark matter within the Milky Way is only 80% of the mass of the galaxy, and not say 95% as some researchers suggest... this would make it 400% of the mass of the observed portion of the galaxy. These stars are, according to the article, 1% of the mass of the (previously) observed portion of the galaxy. Which makes them 0.25% of the mass of dark matter required to account for gravitational effects that are otherwise unexplained. If dark matter turns out to be a significantly larger percentage, such as 95%, then these stars only account for .05% of the mass of dark matter.

For those who question the value of determining either the cause or the exact amount of dark matter in the universe, this debate is pivotal for determining the final fate of the universe. So far our calculations of the total mass of the universe, including the dark matter, are riding the knife-edge required to make the universe exactly stable. If there is a little more mass than this, then the current expansion of the universe will one day reverse, until the universe contracts back to a singularity. If there is a little less mass than this, then the current expansion of the universe will continue infinitely.

This is all according to current theory on the creation and eventual fate of the universe and is subject to change with brilliance, genius, and persperation.

here's the problem

[rebelcool]

even if you filled the outside of the galaxy with a shell of dead rock, it wouldnt account for the missing mass. There is *alot* of missing mass. Plus itd be easy to spot that, because little light would get through it.

Others suggest alot of neutron stars spinning around out there, also not likely. We'd have noticed them, either by an inordinate amount of nearby pulsars, or simply from gravitational lensing. Same goes for dead hunks of carbon. To make up the missing mass, there would have to be many of these things. And with many of them, the chance of spotting several would be high.

The macho theory suggests there COULD be a *few* but *extremely* massive objects wandering around out there. Something like supermassive blackholes, or something else. If there were a few, and they emitted no light (likely), then they'd be easy to miss.

The other theory suggests that there is some kind of exotic matter which we haven't discovered yet that emits no known form of radiation, but may indeed generate gravity. This is also possible, as the newly discovered 'dark energy''s origins are also unknown. The confirmation of dark energy (which is recent) is what drives the expansion of the universe, and is indeed some kind of 'anti gravity'. Very interesting, but very strange. And we have no idea where the hell it comes from.