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Brown Dwarf With Water Clouds Tentatively Detected Just 7 Light-Years From Earth

Unknown Lamer posted about a month ago | from the a-bit-chilly dept.

Space 85

sciencehabit (1205606) writes Astronomers have found signs of water ice clouds on an object just 7.3 light-years from Earth — less than twice the distance of Alpha Centauri. If confirmed, the discovery is the first sighting of water clouds beyond our solar system. The clouds shroud a Jupiter-sized object known as a brown dwarf and should yield insight into the nature of cool giant planets orbiting other suns.

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Is this the missing "dark matter"? (2, Insightful)

Anonymous Coward | about a month ago | (#47763145)

There was not enough mass in what we can see from the galaxies. And people came up with strange theories like dark matter.

Now we have an (arguably not so super heavy, but nonetheless) object just around the corner. Could it be that there's no dark matter, but that simply the galaxies are full of these things?

Re:Is this the missing "dark matter"? (1)

Anonymous Coward | about a month ago | (#47763169)

not likely as there is too much missing mass (5% is observable mass and 27% is dark matter) of the galaxy and these are small objects less than one tenth of the sun. Also, these are accounted for in the models of the galaxy

Re:Is this the missing "dark matter"? (5, Informative)

mister_playboy (1474163) | about a month ago | (#47763173)

No, the amount of missing matter is far to great to be contained in such small objects even if they were incredibly numerous.

Consider the entire mass of the asteroid belt is estimated to be only 4% of the Moon's mass, and the Moon's mass is only 1/81 of the Earth's.

Dark matter, meanwhile, is thought to have a total mass more than 5 times greater than that of normal matter.

Re:Is this the missing "dark matter"? (2, Informative)

Anonymous Coward | about a month ago | (#47763305)

Logic fail. Dark matter can be explained by such small objects if they are incredibly numerous. It's just math: divide the missing mass by the mass of one brown dwarf to get the number needed. If you want to disprove the brown dwarf explanation you need to explain why the number that is needed contradicts something.

Re:Is this the missing "dark matter"? (5, Insightful)

Buggz (1187173) | about a month ago | (#47763331)

Logic fail. Dark matter can be explained by such small objects if they are incredibly numerous. It's just math: divide the missing mass by the mass of one brown dwarf to get the number needed. If you want to disprove the brown dwarf explanation you need to explain why the number that is needed contradicts something.

The hypothesized dark matter does not emit or absord any type of electromagnetic radiation, in other words it does not interfere with or react to light. Numerous small objects would. Also, and this is the most important bit in your logic fail fail, if you have enough small objects to account for five times the mass of the visible universe, you would have something five times more visible than the visible universe. Matter attracts other matter (which is why there is a dark matter hypothesis to begin with, something invisible attracts the visible) and such a copious amount of "small objects" would form larger objects. Which is how stars and planets form to begin with.

Re:Is this the missing "dark matter"? (0, Interesting)

Anonymous Coward | about a month ago | (#47763343)

Not if it's cold.

Thing is this brown dwarf was hard to find because it's cool, at near the ambient, a few K, invisible.

I also don't think normal matter explains it all either, but I'd be unsurprised if there wasn't quite a lot more normal but very cold matter as well.

Re:Is this the missing "dark matter"? (4, Informative)

joe_frisch (1366229) | about a month ago | (#47763369)

Its not a simple argument but if you look at:
http://en.wikipedia.org/wiki/D... [wikipedia.org]
dark matter composed of bits of normal baryonic matter is not consistent with observations / simulations

Re:Is this the missing "dark matter"? (0, Flamebait)

Anonymous Coward | about a month ago | (#47763415)

Not if it's cold.

Thing is this brown dwarf was hard to find because it's cool, at near the ambient, a few K, invisible.

I also don't think normal matter explains it all either, but I'd be unsurprised if there wasn't quite a lot more normal but very cold matter as well.

You could be on to something. Have you spoken to Stephen Hawking regarding your Cold Matter theory during one of your regular scones & chess meetings?

Re:Is this the missing "dark matter"? (-1)

Anonymous Coward | about a month ago | (#47763473)

I didn't say I thought it was a compelling argument, BUT , it hasn't been eliminated as a possibility yet.
If it's mostly in brown dwarf sized lumps it doesn't have as much impact on incoming light as say diffuse clouds of matter would.

The mere existence of this ONE cool brown dwarf suggests there's a lot more 'cool to cold' matter than suspected - which also messes up the dark matter simulations.

The bullet ?, also explainable by a galaxy collision, one galaxy mostly consisting of cold objects ...

Until 'dark matter' is actually nailed down, I'll remain cynical.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47763699)

BUT , it hasn't been eliminated as a possibility yet.

Yes it has. They have eliminated matter that interacts with light at all in any way and matter that interacts with the electric force, which is a side effect of not interacting with light. Start looking for something not made of electrons, neutrons, protons, or neutrinos. They have all been ruled out.

Re:Is this the missing "dark matter"? (2, Insightful)

Anonymous Coward | about a month ago | (#47764929)

No, they have not eliminated the possibility that dark matter does interact with electromagnetism weakly, which is the basis of some particle detection searches and some scans of the skies for things similar to antimatter-matter interactions. But they have pretty much eliminated that dark matter is dense piles of regular matter (e.g. brown dwarfs, or black holes, or rogue planets) by doing microlensing surveys which set an upper bound on the number of such objects. If there were enough to account for dark matter amounts required for rotation curve of galaxies, they would have seen way more microlensing events than they did. This applies regardless of evidence suggesting that dark matter is not baryonic (the same evidence points out that there is unseen regular matter too, which would mean there is stuff like this not yet observed that needs to be found before you would even start edging into the dark matter category).

Re:Is this the missing "dark matter"? (1)

Livius (318358) | about a month ago | (#47769507)

No, they have not eliminated the possibility that dark matter does interact with electromagnetism weakly

If it's violating Maxwell's laws, then 1) whatever else it is it's not ordinary matter, and 2) that's far-fetched and cool the same way the dark matter hypothesis is.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47772113)

Ordinary matter violates classical Maxwell's laws via matter-antimatter annihilation. Positrons reacting with electrons is not accounted for in the original Maxwell's equations, nor is any other non-linear part of quantum electrodynamics. If whatever particles that compose dark matter have an antimatter form, or interacts with charged particles in a rare reaction, or even just has a really weak coupling to photons in reactions, you can have some interaction with electromagnetism that is below current detection thresholds. Two of those three options happen with ordinary matter as is, just they are typically dwarfed by the more vanillia direct EM interaction.

Re:Is this the missing "dark matter"? (1)

LordLimecat (1103839) | about a month ago | (#47763731)

Whether it has or has not been eliminated, idle speculation isnt compelling. If you havent studied this and / or had extensive experience with it, you probably shouldnt be composing theories on dark matter.

Re:Is this the missing "dark matter"? (-1)

Anonymous Coward | about a month ago | (#47764463)

Fuck off, does this look like a fucking symposium to you? No, then shut the fuck up. This is a discussion board, where people...discuss things. Part and parcel with discussion is opinion. Don't like it? too fucking bad. // And a not for the mods, if you mod this down for being rude that is fine. If you mod it down for the "bad words" then you are taking part in an atrocity. My people were conquered and the new rulers outlawed out language and many people today still think it is okay to punish people for using words from our native tongue. That's where "bad words" came from.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47764731)

Obvious troll is either obvious or unaware that they're butthurt about someone having an opinion about obvious troll's opinion. Opinions for some, miniature flags for people who aren't obvious troll.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47771463)

Opinions are like assholes -- getting reamed out by the first anonymous moderator who happens by.

At least, yours is.

Re: Is this the missing "dark matter"? (1)

James Buchanan (3571549) | about a month ago | (#47764567)

Restating your argument, only those with extensive knowledge of a subject are knowledgable enough to comment? There goes /..no more articles, better get the bible out and only use that for stellar research. You build a theory by standing on the shoulders of others and learning. Modifying the past learning to open the future learning. Otherwise you shut down learning. Learning is the asking of questions. To find a reason something exists or why, or gee, that's neat. That's why science should never be "settled", that means a new dark age. Remember, the bible settled all heracy, such as science, with death. Be a heritic, live,ask, learn.

Re: Is this the missing "dark matter"? (1)

geekoid (135745) | about a month ago | (#47764719)

". You build a theory by standing on the shoulders of others and learning."
Yes. But if you don't even stand on the shoulders of the giants in a field, then you should probably shut the fuck up.

"Learning is the asking of questions."
Yes, but it isn't throwing out ideas so off base they aren't even wrong, and then telling people to show you why they can't be when the idea being stated makes no sense at all. AC who posted that question clearly doesn't know the first thing about dark matter. Frankly, the poster should have the decency to do some preliminary understanding of the problem before spouting off nonsense and then getting defensive about it.

Re: Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47766839)

And you do know the first thing about dark matter?

Re: Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47768461)

Assuming our underlying theory of gravity is correct, the first thing we know about dark matter is that it exerts gravitational forces on it's surroundings. The second thing we know about drark matter is that it's completely invisible in the entire electromagnetic spectrum. This second thing we know means that dark matter is not made up of baryons (i.e. protons, neutrons, anything made of quarks really) because baryons are not invisible.

In order for dark matter to be dark baryonic matter you'd first have to explain why it's so hard to see and then you'd have to explain why more than half the matter in the universe refuses to collapse into a body big enough to heat up.

Again, this all assumes we have gravity licked except that we know we don't because we can't use gravity at the quantum scale. Relativity works great at scales the size of our solar system, but it's the discrepancy between what Einstein's math says should be happening, at scales the size of a galaxy and bigger, and what we observe is happening that led to the idea of dark matter in the first place.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47763655)

Cold object don't interact with light? News to me. Best let the world know of your revolutionary breakthrough.

Re:Is this the missing "dark matter"? (2)

mod prime (3597787) | about a month ago | (#47766613)

Yeah, I liked the MACHO idea many years ago, they may still account for some of the gravity yet, but the position is more or less untenable at this stage both empirically and theoretically.

Re:Is this the missing "dark matter"? (1)

x_t0ken_407 (2716535) | about a month ago | (#47768695)

No matter how cold it is, it would STILL interact with light (being cold does not make something invisible). And given the number of cold brown dwarfs it would take to make up the difference, it would be virtually impossible to NOT have seen them (if they were in fact the the culprits of dark matter) as others have alluded to in this thread.

Re:Is this the missing "dark matter"? (1)

TomGreenhaw (929233) | about a month ago | (#47763453)

If there were that much normal matter out there we'd know because the light from distant galaxies would be more blocked than it is.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47763323)

The dark matter is the packaging material the universe came in. God chucked it into a corner when he unpacked it all. That is why we cannot find it.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47763325)

Brown dwarves contain 10-90 Jupiter masses. The sun is 1,047.56 Jupiter masses. So each brown dwarf is 1-9% as massive as the Sun. That doesn't change your point though. There'd have to be a lot of cool and dim dwarves flying around.

Re:Is this the missing "dark matter"? (4, Interesting)

TapeCutter (624760) | about a month ago | (#47763355)

Exactly, we think of Jupiter as being huge but the Sun holds 98% of all the matter in our solar system. If the "missing mass" were normal cold matter, such a great quantity would effectively block the light of the stars we can see, astronomy would not exists because we wouldn't see anything except our own sun and moon.

Similar inane arguments were aimed at Newton, plenty of 15th century scholars thought that the fact a bird can fly disproved the theory of gravity. We still don't know what the hell gravity is (other than a property of matter) but we no longer question it's existence and have developed a very good understanding of how it behaves. Dark matter is harder to wrap one's head around because it's effects can not be observed in everyday human experience. However the effects are real and the tag scientists have given them is "dark matter".

Re:Is this the missing "dark matter"? (1)

PPH (736903) | about a month ago | (#47765613)

We still don't know what the hell gravity is (other than a property of matter) but we no longer question it's existence and have developed a very good understanding of how it behaves.

Maybe not so good. ts possible that dark matter is just a fudge factor tat we need to apply to Newton's inverse square law over larger distances or for larger masses.

Here's an interesting thought puzzle: Assume the effects of gravity are caried by some yet to be discovered particle/wave (gravitons) and these 'particles' are subject to the same laws of physics that all other partices are (photons, for example). Then how do they escape the gravitational pull of a black hole? If photons can't get out, then how do these gravitons? If gravity exists as a wave, then why wouldn't the gravitational attraction of the black hole bend these waves back around into itself, preventing it's effects on neighboring matter

Re:Is this the missing "dark matter"? (1)

rahultyagi (924414) | about a month ago | (#47765809)

Here is something to boggle your mind. You think your argument is strong with Sun containing 98% of the Solar system's total mass? It is actually something like 99.8%!! to think that stray jupiter-size brown dwarves can weigh anywhere near the total stellar masses that we see betrays complete lack of understanding of the difference of scales involved.

Re:Is this the missing "dark matter"? (1)

Rob Riggs (6418) | about a month ago | (#47769625)

You think your argument is strong with Sun containing 98% of the Solar system's total mass? It is actually something like 99.8%!!

Yep. Here's a good source for the relative masses of the solar system object: http://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size#List [wikipedia.org] . It does not include the Oort Cloud, which is though to contain about 5 Earth masses of material.

Re:Is this the missing "dark matter"? (1)

Rockoon (1252108) | about a month ago | (#47765883)

the Sun holds 98% of all the matter in our solar system. If the "missing mass" were normal cold matter, such a great quantity would effectively block the light of the stars we can see

This simply doesnt compute unless you make assumptions about the distribution of the missing mass, and in this case your argument assumes its distributed evenly (nebula) while also taking advantage of the fact that the actual visible mass (stars) isnt.

Let me translate the flaw so you understand: You are claiming that there is no place to put 100 of these brown dwarfs near a star that wouldnt block the stars light from reaching any of the rest of the universe. (and before you go there, I didnt pull 100 out of my ass. I actually did the relative mass calculation. This brown dwarf is about 1/100th the mass of our star.)

I am not arguing that there isnt good reason to believe that the missing matter cannot be baryons. I am arguing that your understanding of the real arguments is complete and utter bullshit and this explanation is complete and utter bullshit.

Even under 100x magnification, the actual visible stars are unresolvable pinpricks of light. Billions of them literally cover ~zero area of the celestial sphere. Since billions of stars cover almost zero area of the sky, billions of smaller things also cover almost zero area of the sky. Their ability to block out the light of the universe is virtually zero unless we make a low-density assumption (such as what your argument does.) Yet in fact these brown dwarfs are 10 times as dense as our sun, the exact opposite of low density.

The primary reason we exclude brown dwarfs like these as being the dark matter within the galaxies that effects its gravity is the lack of gravitational microlensing that such matter would cause. Its not at all the obstruction of light (that you theorize) as the reason, its the lack of bending of light.
So not only is your theory wrong, its antithetical to the real reason. If we expected the proper amount of brown dwarfs that would explain dark matter to block light, we wouldnt be able to expect the microlensing we actually looked for.

Now dont discuss this subject any more unless you learn at least a few basic things.

Re:Is this the missing "dark matter"? (1)

Viol8 (599362) | about a month ago | (#47766077)

"Now dont discuss this subject any more unless you learn at least a few basic things."

You should follow your own advice. Most brown dwarves are glowing away nicely in infrared. If there were triillions of them they'd be lighting up the sky in that band. They arn't, so unless something has cooled them all down to absolute zero (yeah, right), they don't exist. Back to school for you.

Re:Is this the missing "dark matter"? (1)

TapeCutter (624760) | about a month ago | (#47770829)

Yeah right, brown dwarfs spontaneously arranging themselves so we can conveniently see past them from earth is a very likely scenario. The paradox that you are relying on is that an infinite number of one dimensional points on a number line cannot get you from point A to point B. Stars are not one dimensional points but yes I quite likely exaggerated when I said only the moon and sun would be visible.

Now dont discuss this subject any more unless you learn at least a few basic things.

Your post was interesting and informative but my reaction to this parting shot is - go fuck yourself you arrogant son of a bitch.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about 1 month ago | (#47788539)

Gravitational microlensing is harder to spot than scattering, especially from dust in the photosphere (Sangupta & Krishnan 2001, Sangupta et al 2005). It's difficult to reconcile the GZK cutoff with Jeans clusters of hundreds of billions of micro brown dwarfs of ca. earth mass, and even harder with smaller numbers of more massive brown dwarfs (which would introduce wide-field visible effects). Moreover BDs and micro-BDs cannot be collisionless, and it is difficult to imagine large Jeans clusters going without any collisions at all. Collisions would inevitably produce optical and gamma observables that are simply too rare in our sky.

MIcrolensing is a great way to find local micro-BDs; at kpc range (i.e., out in the halo) there is almost no chance of a visible artifact from an individual micro-BD, and the expectation is that a real Jeans cluster of micro-BDs that *would* produce a detectable lensing would itself be visible for other reasons. In fact, we have found quite a few of them in the thick disk with WISE.

Re:Is this the missing "dark matter"? (1)

Anonymous Coward | about a month ago | (#47763183)

Shouldn't have an impact on the mass estimation of other galaxies, so no.

Re:Is this the missing "dark matter"? (1)

Anonymous Coward | about a month ago | (#47763235)

I'm pretty sure that's where Lando lives.

Occam's razor. (3, Insightful)

TapeCutter (624760) | about a month ago | (#47763327)

Could it be that there's no dark matter, but that simply the galaxies are full of these things?

Could it be that all the cosmologists and physicist who have been looking at this for a couple of decades somehow missed that blindly obvious "possibility". Or is it more likely you are simply unaware of the evidence [wikipedia.org] that forces these people to dismiss the obvious "common sense" answer?

Re:Occam's razor. (1)

Anonymous Coward | about a month ago | (#47763339)

A better reply would have been "No, and here's why." Nice and all civil-like. Try it! You'll be surprised by its effectiveness.

Re:Occam's razor. (1)

Electricity Likes Me (1098643) | about a month ago | (#47763357)

I'd be un-surprised when it leads a half-dozen "gotcha" worded follow ups from someone who clearly has no interest in Googling their own ideas first.

Re:Occam's razor. (1)

smitty_one_each (243267) | about a month ago | (#47763381)

tl;dr: "Welcome to /."

Re: Occam's razor. (-1)

Anonymous Coward | about a month ago | (#47763551)

Die in a fire, faggot.

Re:Occam's razor. (3, Insightful)

TapeCutter (624760) | about a month ago | (#47764299)

How was my reply "uncivil"? Blunt with just a hint of sarcasm certainly, but there's nothing in there that should offend someone who is genuinely interested in an answer. In fact I deliberately used the word "unaware" because "ignorant" is normally viewed as derogatory (even though it actually isn't).

If you feel a gentler more informative answer can be provided then why not provide it? I'm sure the OP is quite capable of defending himself against my prose if it has unintentionally offended him in some way that I'm unaware of. What I'm not so sure of is why do you feel the need to be offended on his behalf?

Re:Occam's razor. (1)

coastwalker (307620) | about a month ago | (#47772829)

Posters do not have to pander to idiots just to be civil. There is nothing wrong with a bit of boisterous prose.

The associated subject of the impossibility of human interstellar travel is another one that people never admit

Mind you it is a bit dull realizing that the human race is stuck in this solar system forever, never mind just for now.

Re:Occam's razor. (0)

Anonymous Coward | about a month ago | (#47764915)

Don't take it personally. This is just how a typical, asocial nerd waves their dick.

Re:Occam's razor. (3, Interesting)

idji (984038) | about a month ago | (#47763515)

No, Astronomers have asked the WIMP [wikipedia.org] vs MACHO [wikipedia.org] question for many decades now, and WIMPs are winning.

Occam's Razor has always been applied here, and that is why it is still an open question, because the simple and obvious answer (MACHO) is not working and extraordinary evidence is being found, eg the Physic's Nobel Prize 2011 [wikipedia.org] .

This article is not about MACHO vs WIMP. It says they found a nearby MACHO with water vapor, and that is very interesting for life questions, not dark matter questions.

Re:Occam's razor. (2)

TapeCutter (624760) | about a month ago | (#47764153)

Very interesting but kind of irrelevant since the question I was addressing asked if brown dwarf could be the famous "missing matter". What we have actually observed is the effects of a gravitational field, precisely what is causing that field to manifest itself we don't know, but we have known for a long time it's not an overabundance of brown dwarfs.

Re:Occam's razor. (1)

Sperbels (1008585) | about a month ago | (#47764877)

How about an overabundance of black holes?

Re:Occam's razor. (0)

Anonymous Coward | about a month ago | (#47764945)

Mostly ruled out by microlensing studies, which is the real damning evidence against machos, not to mention they are expected to be mostly normal matter and cosmological evidence rules out baryonic dark matter.

Occam's razor. (0)

Anonymous Coward | about a month ago | (#47763685)

It could be. They even managed to not account for relativistic effects and the speed of light in the beginning when studying galaxies.

Re:Occam's razor. (1)

Anonymous Coward | about a month ago | (#47763929)

Could it be that there's no dark matter, but that simply the galaxies are full of these things?

Could it be that all the cosmologists and physicist who have been looking at this for a couple of decades somehow missed that blindly obvious "possibility".

Because cosmologists are never finding anything new? Im not trying to stir anything up, especially since you seem to have an emotional stake on this topic.

Re:Is this the missing "dark matter"? (2)

idji (984038) | about a month ago | (#47763487)

No, MACHOs [wikipedia.org] do not account for all the Dark Matter in the Universe.

Re:Is this the missing "dark matter"? (2)

Charliemopps (1157495) | about a month ago | (#47763663)

No, Dark matter does not interact with normal matter. We can "See" light and radiation pass unimpeded through areas that contain detected dark mater. It does not reflect, bounce off of or interact in any other way... except it's gravitational pull. That's why it's called "Dark" Moving light/radiation will bend around it, but not bounce off of it.

Re:Is this the missing "dark matter"? (1)

Intrepid imaginaut (1970940) | about a month ago | (#47763783)

Like dimples in space.

Re:Is this the missing "dark matter"? (1)

Rei (128717) | about a month ago | (#47764313)

Like letting the air out of a balloon!

Re:Is this the missing "dark matter"? (1)

Drethon (1445051) | about a month ago | (#47763729)

At the moment, dark matter is just a place holder in equations to make the equations match observations. It remains to be seen if the placeholder will one day be observed or the equations need to be rewritten (if just slightly) to match actual observations.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47763755)

What I don't get is that they didn't find any missing mass like that within the confines of the Solar system. At ratios like those, I'd assume we'd be swimming in it around here as well, and we'd see its gravitational activity without having to travel the galaxy.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47768667)

Assuming dark matter is distributed around it's center of mass like matter would be, the room your in should be full of dark matter. There should be as much dark matter as there is matter, but you can't possibly see it (because it's invisible). I believe the reason it doesn't effect our calculations regarding the mass of our solar system or sun is that it's distributed in such away that there's as much gravitationally pulling you away from the earth as there is pulling you back down, so the effect zeroes out. It isn't until we deal with the voids between galaxies that the 'location' of the dark matter seems to make a difference.

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about 1 month ago | (#47789201)

It's not clear whether there is a dark matter gradient and how it's shaped; there is evidence that in elliptical galaxies it is mostly concentrated at a great distance from the centre, but the evidence is more mixed for spiral galaxies. The distribution is mostly gleaned by looking at where gravity points and then looking for mass-energy there; where there's no ordinary matter visible, there are tests to determine whether it's likely to be dark matter instead.

The explanation for why it might concentrate well outside the galaxy is that dark matter feels gravity and is swept up by the galaxy's gravity (and in turn contributes to it) but in the CDM model, it is collisionless and non-radiative, so it cannot easily convert momentum to some other energy, and thus it stays in mostly non-collapsing orbits. Ordinary matter by contrast can collide and transfer momentum -- for instance it can heat and radiate energy away as light or particle radiation -- and having lost energy-momentum, will fall into an orbit closer to the galactic centre of mass.

There are plausible explanations to explain a variety of gradients and uniform densities in elliptical galaxies, and some for spiral galaxies too. However, even with a steep increase in dark matter in the middle of the Milky Way, the local density of dark matter is very small everywhere our planet. If it's something similar to a "gas" of heavy neutrinos, then it would still only be a few thousand particles per cubic metre (equivalent in mass to about two protons), which on its own would be an excellent effective vacuum. (Additionally the DM would just pass through your room unnoticed, just as the much larger number of ordinary (lighter) neutrinos do). Even quadrupling the density of the dark matter nearer the sun, for the sake of argument, it would still be very diffuse.

However, the dark matter extends out much further than the brightly visible matter in the Milky Way, like a spheroidal cloud (or at least a very very thick disk) with a bright thin and smaller-radius disk embedded in it.

Re:Is this the missing "dark matter"? (1)

Rei (128717) | about a month ago | (#47764267)

And how do magnets work, HMMM?????

Re:Is this the missing "dark matter"? (0)

Anonymous Coward | about a month ago | (#47764549)

Nope. Not even remotely.

If there were the number of brown dwarfs out there needed to fill in the space for dark matter, you'd literally see stars across the entire universe popping in and out of existence harder than the virtual particles do.
There would be an absolute FUCKTON of brown dwarfs out there, all obscuring the view of the universe at random.
It would be trivial to spot them.

There are galaxies with large, dark bands that could be brown dwarfs, but it certainly isn't dark matter.

Is this the missing (0)

Anonymous Coward | about a month ago | (#47768223)

You say that like you think it's a new idea, when in actuality that's the first thing that was hypothesized to explain the discrepancy. The term "Dark Matter" is actually a reference to the idea that it was ordinary matter that's hard to see.

Later observations contradicted this hypothesis as we've detected objects that have mass but don't block or emit EM radiation (implying they aren't normal matter).

Re:Is this the missing "dark matter"? (1)

Livius (318358) | about a month ago | (#47769397)

No.

Dark matter is matter that does not interact with electromagnetic forces. It isn't mass that's gone missing.

First non-cloud candidate (3, Interesting)

mdsolar (1045926) | about a month ago | (#47763163)

The abstract says "this is the first candidate outside our own solar system to have direct evidence for water clouds." Which is true in the sense that water in star spots is vapor and not condensed. However molecular clouds often have water ice in them and so might be considered water clouds if condensation is the criterion. This is cool discovery.

I thank you for your Time (-1)

Anonymous Coward | about a month ago | (#47763255)

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Anonymous Coward | about a month ago | (#47763397)

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Is this the same brown dwarf that... (1, Offtopic)

Jason Goatcher (3498937) | about a month ago | (#47763481)

Wants to know what Willis is talkin' bout?

Re:Is this the same brown dwarf that... (0)

Anonymous Coward | about a month ago | (#47764387)

I've read your posting history. Overall, you contribute little to discussions and generally you make really stupid comments. I'd like to request that you please stop posting, as it its bringing down the general intelligence of this site. Thank you for your consideration.

Re:Is this the same brown dwarf that... (0)

Anonymous Coward | about a month ago | (#47790523)

Hey, I know: why don't you fuck off back to Facebook?

The theorized nemesis star? (1)

Dukenukemx (1342047) | about a month ago | (#47763535)

It's been said that the sun might have a brown dwarf that orbits it. Seven light years isn't that far off.

Re:The theorized nemesis star? (3, Interesting)

Overzeetop (214511) | about a month ago | (#47764195)

The brown dwarf that orbits the sun is called Jupiter.

Re:The theorized nemesis star? (1)

Zephyn (415698) | about a month ago | (#47765707)

There's a mass and temperature difference between gas giants and brown dwarf stars. The cutoff is whether the object in question has any fusion going on at all. At about 13x Jupiter mass it's big enough to fuse deuterium, and at 65x it can fuse lithium. If it's massive enough to fuse hydrogen, you've crossed into Red Dwarf territory (oh smeg!).

No form of sustained fusion has ever been detected within Jupiter, so it's not a brown dwarf, just a gas giant planet.

Re:The theorized nemesis star? (0)

Anonymous Coward | about a month ago | (#47766847)

Jupiter's not a brown dwarf, although it does radiate more heat than it receives from the Sun. The smallest brown dwarves are more than 10 times Jupiter's mass.

Re:The theorized nemesis star? (0)

Anonymous Coward | about a month ago | (#47768259)

How the fuck does nonsense like this get modded up?
 
Oh, it's because of all the "Science!" herp on shit like the "Science" channel that makes you think that Jupiter is a failed star... utter bullshit and cunts who spread these lies should eat shit and die.
 
May as well be worshipping faggot ChristAllah when you start preaching this kind of totally misdirected shit.

Re:The theorized nemesis star? (1)

Anonymous Coward | about a month ago | (#47764373)

Seven light years is that far off. There's multiple star systems between us and it, which would interfere with it's orbit.

Re:The theorized nemesis star? (0)

Anonymous Coward | about a month ago | (#47765249)

However some of the other 'theories' (if you want to call them that) indicate that the brown dwarf was a wanderer that was caught in an unstable orbit and since then ejected from the system as well. I'm not sure of velocities and vectors involved here but should things line up properly it could fit with one of those ideas.

Reality on the other hand says this brown dwarf and Sol have likely never been close enough for any amount of significant interaction.

Going to Battle (1)

gsslay (807818) | about a month ago | (#47763575)

From the article;

"I went to battle at the telescope to try and get this detection," Faherty says. "I wanted to put war paint under my eyes and wear a bandanna, because I knew this was not going to be an easy thing to do."

Who said astronomy was dull? There has to be a TV series to had here. Action Astronomer wields her mighty War Telescope!

Re:Going to Battle (1)

pr0nbot (313417) | about a month ago | (#47763627)

Episode 16: The missing TPS cover sheet

Moons? (1)

MichaelSmith (789609) | about a month ago | (#47763631)

I wonder if it has any Earth sized moons. Maybe one close in could be kept warm(ish) by tidal heating.

Re:Moons? (3, Informative)

Rei (128717) | about a month ago | (#47764441)

Indeed it does. I haven't published yet, but I detected one a few days ago (I work out of a valley in Iceland). I observed the brown dwarf in question (right ascension 08h 55m 10.83s, declination -07 14 42.5") and detected a large, earth-sized body occluding the star during my brief observations.

Re:Moons? (1)

Anonymous Coward | about a month ago | (#47764531)

Ahhh ... Slashdot ... where some posts are impossible to differentiate between humor and sheer awesomeness.

Re:Moons? (1)

NormalVisual (565491) | about a month ago | (#47766871)

So I'm assuming the IAU will be naming it "REI-128717"? ;-)

Re:Moons? (1)

MichaelSmith (789609) | about a month ago | (#47772585)

Could that body have been... The Earth? The same thing happens whenever I try to look at Paris from Australia.

Re:Moons? (1)

geekoid (135745) | about a month ago | (#47765181)

Well, it's funny you say that.

We saw two moons. One of which wasn't in earlier detections, and as it came around the brown dwarf, it just exploded. weird.

Re:Moons? (1)

MichaelSmith (789609) | about a month ago | (#47772583)

Its clearly a trap.

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