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Frigid Brown Dwarf Found Only 7.2 Light-Years Away

Soulskill posted about 6 months ago | from the interstellar-stalker-hiding-in-the-bushes dept.

Space 142

An anonymous reader writes "Astronomer Kevin Luhman just found the 7th closest star to the sun. It's a mere 7.2 light-years away, discovered using NASA's Spitzer and WISE telescopes. How could it exist so close for so long without us knowing? It's a brown dwarf — barely a star at all. 'Brown dwarfs are star-like objects that are more massive than planets, but not quite massive enough to ignite sustained fusion in their cores. Hydrogen fusion is what powers the Sun, and makes it hot; it's the mighty pressure of the Sun's core that makes that happen. Brown dwarfs don't have the oomph needed to keep that going.' This small almost-star is downright chilly at around 225-260 Kelvin. That's -48 to -13 C (or -54 to 9 F). As Phil Plait points out, that's not much different from the temperature in the freezer in your kitchen. He adds, 'It implies this object is very old, too, because it would've been a few thousands degrees when it formed, and would take at least a billion years to cool down to its current chilly temperature. It's hard to determine how old it actually is, but it's most likely 1-10 billion years old. It has a very low mass, too, probably between 3 and 10 times the mass of Jupiter. That's pretty lightweight even for a brown dwarf. And here's another amazing thing about it: It might be a planet. What I mean is, it may have formed around a star like a planet does, then got ejected by gravitational interactions with other planets.'"

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Frigid Brown Dwarf (-1)

Anonymous Coward | about 6 months ago | (#46848617)

Would have made a good wife for Gary Coleman.

Age range? (4, Insightful)

Anonymous Coward | about 6 months ago | (#46848707)

"...most likely 1-10 billion years old."

That doesn't narrow it down much, given everything in the universe is in the 0-13.8 billion year range.

Re:Frigid Brown Dwarf (0)

ControlsGeek (156589) | about 6 months ago | (#46848769)

I knew a girl like that once.

Re:Frigid Brown Dwarf (5, Funny)

turkeydance (1266624) | about 6 months ago | (#46848925)

Google that without SafeSearch. ewwww.

Re:Frigid Brown Dwarf (0)

Anonymous Coward | about 6 months ago | (#46849551)

"Would have made a good wife for Gary Coleman."

You insensitive clod!

These are temperature-challenged little people of non-Caucasian origin.

That's no moon. (0)

Anonymous Coward | about 6 months ago | (#46848661)

It's a super-giant planet or a super-dwarf star.

Re:That's no moon. (1)

ShanghaiBill (739463) | about 6 months ago | (#46850423)

It's a super-giant planet or a super-dwarf star.

If it is big enough to ignite fusion, then it is a star. A mass of about J8 (eight Jupiters) is needed to fuse deuterium. Most likely, that is not happening, or it would not be so cold. So it is not a star. But I don't think it is a planet either, because it is only a planet if it is orbiting a star. So I don't know what it is called.

Re:That's no moon. (0)

Anonymous Coward | about 6 months ago | (#46850671)

It's a super-giant planet or a super-dwarf star.

If it is big enough to ignite fusion, then it is a star. A mass of about J8 (eight Jupiters) is needed to fuse deuterium. Most likely, that is not happening, or it would not be so cold. So it is not a star. But I don't think it is a planet either, because it is only a planet if it is orbiting a star. So I don't know what it is called.

rogue planet

Re:That's no moon. (1)

sillybilly (668960) | about 6 months ago | (#46851605)

I think I read somewhere that the inner core temperature of Jupiter is higher than it should be, and chemical engineering 101 says if heat out minus heat in not equal zero, then there is heat generated. The inner lava temperature of Earth is sustained mostly by K40 and U235 decay, besides minor asteroid impacts. So the inner temperature of Jupiter is also sustained probably by the same thing, and not fusion, as it is hard to imagine Jupiter without an iron-nickel core, and lava, and then a hydrogen atmosphere. Ditto for this "nonstar," it's hot for the same reasons that the inside of the Earth and Jupiter is hot, mostly K40 and U235.

close enough to mine (0)

Anonymous Coward | about 6 months ago | (#46848669)

this could supply us with an endless source of resources correct? SPICE SPICE!

Re:close enough to mine (2)

Immerman (2627577) | about 6 months ago | (#46849033)

Sure, right after we finish mining Jupiter and develop FTL drives to get there.

Re:close enough to mine (1)

HiThere (15173) | about 6 months ago | (#46850557)

Well, it's only 7.2 lightyears away, so you don't need an FTL drive, you just need a LOT of patience. But what you really need is some way to cheaply get the mass away from a star's gravitational field. True, it's quite a small star, but at 3-10 times Jupiter's mass, it will take 9-90 times as much energy to extract it. (That's an estimate, not a calculated answer...but escape velocity goes up faster than the mass, or you'd almost never get a black hole.)

Re:close enough to mine (1)

Immerman (2627577) | about 6 months ago | (#46851241)

Talk about a killer commute...

Re:close enough to mine (0)

Anonymous Coward | about 6 months ago | (#46850677)

Well aren't you just the Luddite? You know, hard drives got better, so obviously because we can make smaller bits, this automatically means we are also able to manipulate high energy levels. FTL will happen just as surely as 3TB hard drives. It's inevitable.

Re:close enough to mine (1)

Immerman (2627577) | about 6 months ago | (#46851255)

Obviously, but what worries me is that Relativity is correct that any form of FTL travel can inherently be repurposed as a time machine to travel into your own past. The integrity of lottery will be destroyed forever, and the complete collapse of civilization can't be far behind.

Re:close enough to mine (2)

Wycliffe (116160) | about 6 months ago | (#46851419)

Not any form of FTL travel. Warp drives as currently proposed don't allow travelling into the past and
there might be tweaks to relativity or other as yet unknown methods like worm holes, etc.. that allow
faster travel.

It might be a planet (2)

rossdee (243626) | about 6 months ago | (#46848673)

No, it might have been a planet once, but its not orbiting a star now so its not a planet.

Re:It might be a planet (5, Informative)

olsmeister (1488789) | about 6 months ago | (#46848681)

That would make it a rogue planet [wikipedia.org] .

Re:It might be a planet (2)

idji (984038) | about 6 months ago | (#46848839)

A planet that is ejected from a star is called a Rogue Planet [wikipedia.org] and just orbits the galaxy itself.

Re:It might be a planet (1)

FatLittleMonkey (1341387) | about 6 months ago | (#46851663)

Unless is used to orbit the sun, it was never a planet under the current definitions.

If you're gonna be pedantic, be pedantic.

Nearest Star? (0)

Anonymous Coward | about 6 months ago | (#46848685)

I thought Alpha Centauri was 4 light years from the Sun?

Re:Nearest Star? (1)

Anonymous Coward | about 6 months ago | (#46848729)

Astronomer Kevin Luhman just found the 7th closest star to the sun.

Damn your reading comprehension sucks.

Re:Nearest Star? (1)

K. S. Kyosuke (729550) | about 6 months ago | (#46848933)

Or, he should simply rotate his screen about 20 degrees clockwise to see the 7 under the right angle.

Re:Nearest Star? (1)

davester666 (731373) | about 6 months ago | (#46848761)

TFS mentions it is the "7th closest star to the sun"

Re:Nearest Star? (0)

davester666 (731373) | about 6 months ago | (#46848799)

curious fact, it is the 5th closest star to earth.

Re:Nearest Star? (1)

radiumsoup (741987) | about 6 months ago | (#46848881)

wouldn't that be the 8th closest star to Earth?

Re:Nearest Star? (1)

davester666 (731373) | about 6 months ago | (#46848939)

no, because when it is the 8th closest star to earth, we need to be on the other side of our orbit around the sun, and we couldn't see it anymore, because the sun is in the way. duh.

Re:Nearest Star? (1)

Anonymous Coward | about 6 months ago | (#46849203)

You don't need line-of-sight for something to exist. What are you, a 2 year old?

Re:Nearest Star? (1)

davester666 (731373) | about 6 months ago | (#46849273)

well, a 2 year old would equate "couldn't see it anymore" with not existing...

Re:Nearest Star? (3, Informative)

Anonymous Coward | about 6 months ago | (#46849525)

The Sun is ~1 AU away, the three Alpha Centauri stars are 4.24 to 4.37 l.y. away, Bernard's star is just under 6 l.y. away, and the two Luhman 16 brown dwarfs are just over 6.5 l.y. away. The position of Earth in its orbit is not enough to make any of those exceed 7.2 light years. this is either the 8th closest star that we know of, or it is not considered a star at all if you don't want to count brown dwarfs (or might be pushing the lower limit of what is a brown dwarf).

How could it exist for so long without us knowing? (4, Insightful)

Viol8 (599362) | about 6 months ago | (#46848701)

You try spotting something that cold and not much bigger than jupiter 7 light years away! I'm incredibly impressed they've managed to spot it at all and should be congratulated since it'll barely even register in the infrared never mind visible light.

Re:How could it exist for so long without us knowi (0)

Anonymous Coward | about 6 months ago | (#46851295)

Somewhat left the door open just a crack and they spotted the fridge light.

Okay, stupid question from a non-astronomer... (2, Interesting)

Anonymous Coward | about 6 months ago | (#46848705)

I keep hearing about "Dark Matter" as an explanation for how galaxies don't fly apart due to the force generated by their rotation, but I can't help thinking that all that mass we're looking for in galaxies could be stuff like this. Regular matter that just doesn't generate enough heat or light for us to have noticed prior to this.

Could the question of how galaxies rotate be answered by large quantities of objects such as these?

Re:Okay, stupid question from a non-astronomer... (5, Informative)

Blaskowicz (634489) | about 6 months ago | (#46848797)

That's part of the MACHO hypothesis regarding dark matter. We could explain away dark matter with trillions of brown dwarfs but that doesn't seem satisfactory for astronomers and cosmologists. For some reason (big bang and cosmic background calculations etc.) we know think that baryonic (regular matter) is only about 4% of the universe's amount of mass-energy and about 25% of non-baryonic dark matter is needed to make it all fit. Not enough baryonic matter to have enough brown dwarfs playing the role of dark matter in/around galaxies.

Re:Okay, stupid question from a non-astronomer... (1)

Jeremy Erwin (2054) | about 6 months ago | (#46849177)

this 2010 preprint [arxiv.org] suggests two types of dark matter.

We shall follow an approach with two types of dark matter, “Oort” DM in galaxies, composed of baryons, and “Zwicky” DM in galaxy clusters, the true DM.

suggesting that micro brown dwarfs can't explain everything. The authors posit that Oort DM is composed of MBDs, and Zwicky DM is composed of massive neutrinos.

But the paper appears not to have been published, so I'm not sure what to think.

Re:Okay, stupid question from a non-astronomer... (2)

Electricity Likes Me (1098643) | about 6 months ago | (#46849337)

Actually it's galactic rotation curve stuff: you can show what the observed vs. dark mass difference is by looking at the motion of stars along the plane of the galaxy. And when you start to propose that it's all asteroids and brown dwarfs, you run into problems - because if there were so many out there, then why don't they ever get heated up by all the radiation they'd be absorbing? And why don't they seem to ever meaningfully collide and experience other types of interactions (the famous bullet nebula picture).

Re:Okay, stupid question from a non-astronomer... (2, Informative)

Anonymous Coward | about 6 months ago | (#46849539)

It is not just the comological level, but searches have been done for small objects roaming around the galaxy by looking for micro lensing events and occlusion events where rogue planets or objects move in front of other stars. If a large portion of the missing mass needed for the galaxy rotation curve were these planets, you can work out the chances of such objects passing in front of the stars being observed for such effects, and find that we should have seen way more than was actually observed.

Re:Okay, stupid question from a non-astronomer... (1)

Anonymous Coward | about 6 months ago | (#46849885)

I really can't stand the Dark Matter & Dark Energy theories; it's just the luminescent ether theory in a new guise.

I strikes me that it's far more likely that our measurements are terrible or we have a basic misunderstanding, rather than inventing a whole new class of matter that has to make up 96% of the universe to make the figures balance.

Then again I was actually disappointed when the LHC announced a 7-sigma result for the Higgs Boson...

Re:Okay, stupid question from a non-astronomer... (1)

Anonymous Coward | about 6 months ago | (#46850089)

it's just the luminescent ether theory in a new guise.

Just not luminescent, or a propagator medium for a wave, and further from the concept of an ether than classical fields.

Re:Okay, stupid question from a non-astronomer... (1)

Anonymous Coward | about 6 months ago | (#46850647)

I strikes me that it's far more likely that our measurements are terrible or we have a basic misunderstanding, rather than inventing a whole new class of matter that has to make up 96% of the universe to make the figures balance.

And yet even after we have repeatedly asked you to show your math leading to your hypothisis, you once again refuse to do so!

Current theory that you say is wrong is the exact same thing that gave us computers, the very tool you are using to state the theory is wrong.
What has *your* theory given technology lately? One thing? two? Once you catch up to the hundreds of scientific fields that have brought us billions of tangable products - and also explains the missing mass better - we will continue to call your bunk for the bunk it is.

When it comes to math, put up or shut up. If you refuse to show your work, don't be shocked when we call you out for cheating and having no understanding of the topic at hand.

Re:Okay, stupid question from a non-astronomer... (1, Interesting)

TrollstonButterbeans (2914995) | about 6 months ago | (#46850959)

Dark matter and dark energy are kludges thrown into an equation because the equation is incomplete.

Like a formula with 2 unknowns, X and Y, with undefined values for each.

Dark matter might as well be called "behavior of gravity or a gravity-like force that we don't understand or observations that could be wrong or misunderstood so far".

Dark energy might as well be called "Looks like we might have expansion if we understand the observations right and since we don't understand this either, let us say there is dark energy".

Do you think 96% of the universe is dark matter and dark energy or do you think that more likely our understanding is 96% incomplete or that some ideas of measurements at great distances are terribly wrong due to something we are assuming (and shouldn't be) or something we didn't think of so far or that our ideas of the fundamental forces still have some major discoveries?

We have some great and compelling ideas in cosmology and physics, but we are not so far along that we don't have much more to go, hell we've supposedly observed quark quartets -- which I guess aren't supposed to happen --- so let's assume the safe thing = we have a lot to learn about the universe still.

Re:Okay, stupid question from a non-astronomer... (0)

Anonymous Coward | about 6 months ago | (#46848835)

Nah, they'd have to be all over the place. There's so much matter missing that if it were brown dwarfs and such, they'd be showing up everywhere blocking light from brighter objects, etc.

Re:Okay, stupid question from a non-astronomer... (0)

Anonymous Coward | about 6 months ago | (#46848863)

The thing with brown dwarfs is that compared to stars they are really small and as such don't hold much mass. Or you could look at it from the other end, compared to anything else, stars are really really big. And therefore contain almost all the mass that's out there.

Re:Okay, stupid question from a non-astronomer... (1)

Immerman (2627577) | about 6 months ago | (#46849129)

Let's see, this brown dwarf is unusually small, and still between 3-10x the mas of Jupiter. Jupiter is about 5% the mass of the sun, meaning this dwarf is 15%-50%solar masses. Meanwhile even the very largest stars such as VY Canis, which is larger than the orbit of Jupiter, is actually estimated at only 17 solar masses, and the vast majority of stars are actually various dwarfs not so unlike our own. So, assume 10 dark sub-dwarf "stars" for every visible star and you've just doubled the mass of the galaxy without hardly trying. Of course there's a question of how much aggregate occlusion and gravitational lensing they would cause, but if we've only just discovered this sucker practically on our doorstep I lean towards thinking it might not be as obvious as often assumed.

Re:Okay, stupid question from a non-astronomer... (1)

Electricity Likes Me (1098643) | about 6 months ago | (#46849353)

Now do that 20 more times and come back with an explanation as to why all that matter doesn't ever seem to interact. You're proposing to solve dark matter by saying there's about 200 brown dwarfs per star. How come they don't collide? Why didn't they collapse into just being, you know, stars?

We know why we'd have trouble finding near cold objects: the sky is relatively poorly lit, and so you have to hope to see them crossing or occluding another light source.

But how do you explain why we don't detect these hundreds of objects in front of other stars? These aren't small things, and we can detect wayward exoplanets, but if there's so many how come they haven't been turning up at a clipping rate?

Re:Okay, stupid question from a non-astronomer... (0)

Anonymous Coward | about 6 months ago | (#46849627)

Aren't there many more Red Dwarf stars than larger stars? Isn't it possible that there are many more Brown Dwarfs than Red Dwarfs?

Re:Okay, stupid question from a non-astronomer... (1)

Electricity Likes Me (1098643) | about 6 months ago | (#46849713)

We know there are a lot of red dwarfs in the vicinity of Sol, but we don't know that this trend continues throughout the galaxy because they're hard to observe.

Of course, that's % of stars we can see. The problem is, the math says of that % we can see, they only make up about 4% of all matter in the universe.

Which again, gets to the problems of scale. 20 times more stuff that we somehow never see is a lot. And it's not just that we never see it - it's that somehow it avoids clumping up into being matter we can see. Dark matter is proposed because the amount of extra mass is ludicrous if it's ordinary baryonic matter, because over the evolution of the universe the forces which normally give rise to stars and planets would have caused all the "unseen" matter - if it can interact non-gravitationally - to also form stars and planets.

Then you get into other problems: stars can be relatively isolated because they have radiation pressure once they form. They actively blow material and gas away from them. Things that aren't fusing though don't really have this, which means they'll have an easier time picking up new matter, which in turn means they can keep gaining mass till they can ignite (at which point they'll slow down again).

Re:Okay, stupid question from a non-astronomer... (1)

FatLittleMonkey (1341387) | about 6 months ago | (#46851743)

There almost certainly are more brown dwarves than other star type, but their relative mass is tiny. About 1% of a solar mass. So to account for dark matter, you'd need over 1000 brown dwarves for each and every other star in the galaxy.

Re:Okay, stupid question from a non-astronomer... (1)

Immerman (2627577) | about 6 months ago | (#46851153)

Well, assuming they didn't collide they also couldn't very well collapse into true stars, they just don't have enough mass. And assuming they're basically gaseous (mostly hydrogen after all) even a near-direct collision wouldn't necessarily cause a significant increase in mass of the larger surviving "fragment".

As for where they are, how about the outside rim of the galaxy? It would seem to me that the further you get from the heart of a young galaxy the thinner the gas clouds get spread, the less material there is in any given proto-stellar disc, and thus the smaller and less likely to ignite the resultant "stars" will be. A lot of non-luminous mass concentrated outside the visible disc would also go a long way towards explaining the anomalous galactic rotation (though even simply using General Relativity equations instead of Newtonian gravity in the analysis mostly solves the problem on it's own). For now, as I understand it, we really don't have much idea what the rim of our galaxy actually looks like - there's too many stars in the way to see anything clearly. Not to mention we're only beginning to be able to detect such small brown dwarfs today when they're on our doorstep.

Re:Okay, stupid question from a non-astronomer... (1)

Sperbels (1008585) | about 6 months ago | (#46851345)

But how do you explain why we don't detect these hundreds of objects in front of other stars?

You're assuming these transits would occur frequently and that we actually have the equipment pointed at the sky to detect them. Even if there were 200 times as many brown dwarfs as stars in the galaxy, actually seeing one pass in front of another star would be an extremely rare occurrence and we'd only detect if we were looking right at that star. Even then we'd only detect a small decrease in light and we'd be unable to distinguish it from the transit of a planet with a long orbital period. Also, consider the velocity of stars in relation to each other? The transit may only visible for a fraction of a second...in which case we wouldn't be able to detect it at all.

These aren't small things, and we can detect wayward exoplanets

Brown dwarfs are small. And we can only detect exoplanets by detecting the effect they have on the wobble of the host star, by their transit of the star, or very rarely we can see light from extremely hot planets.

How come they don't collide? Why didn't they collapse into just being, you know, stars?

Even at 200 times, collisions would be extremely rare. And the collision would be a non-event as far as the earth is concerned. Why don't they collapse into stars [assuming the collision produced a star with sufficient mass to be a star]. Maybe they are? Still the collisions would be so rare that we'd almost certainly never witness the event.

if there's so many how come they haven't been turning up at a clipping rate?

The only part of your argument that really works. Even with the limited instruments we have now, we'd expect to see more if there were 200 times as many brown dwarfs. But then, we're discovering a lot more of these now that we have instruments designed to find them. Regardless, I don't think 200 times the number would account for the missing mass.

So this is Planet X? (0)

Anonymous Coward | about 6 months ago | (#46848731)

How long until it makes it here?

Re:So this is Planet X? (2)

Immerman (2627577) | about 6 months ago | (#46849137)

Well, I hear the collision with the Andromeda galaxy will shake things up a bit in interstellar space in about 4 billion years...

Re:So this is Planet X? (1)

Streetlight (1102081) | about 6 months ago | (#46849321)

Well, I hear the collision with the Andromeda galaxy will shake things up a bit in interstellar space in about 4 billion years...

And by then the sun will be a red giant with a radius as large of not larger than the earth's orbit. We're going to be pretty well fried by then.

Re:So this is Planet X? (1)

Immerman (2627577) | about 6 months ago | (#46851055)

Actually estimates are that the red giant transition is 4 to 7 billion years out, so the Andromeda collision will roughly coincide with the lower end of estimates of our sun's lifespan in it's current state. It could also turn out that it will have another 3 billion years after the the collision begins.

Fuck the IAU (0)

l0ungeb0y (442022) | about 6 months ago | (#46848737)

It might be a planet. What I mean is, it may have formed around a star like a planet does, then got ejected by gravitational interactions with other planets

So now not only aren't Planets really Planets, Stars aren't really Stars.
The IAU and their new speak seriously needs to fuck off.

What this card carrying member of the IAU **SHOULD** have said is "This likely was a member of a BINARY system that got ejected by gravitational interactions".

But no... he has to go goose-stepping with his IAU speak and call a star a fucking planet.

Re:Fuck the IAU (1)

Immerman (2627577) | about 6 months ago | (#46849175)

Well maybe, but if this thing was never fusing was it ever really a star? And if it was fusing, but has now completely stopped, then the question is did it stop being a star while still orbiting it's primary, and thus become a planet first, or did it get ejected as a star and become a planet later? For that matter is there really such a thing as a rogue planet? Planet means wandering star, and we now know that it's only the act of orbitting a star that causes a planet to "wander" across the stellar background - without a star a rogue "planet" will maintain formation on the relevant timescales, just like the visible stars.

Or we could all sit down like adults and recognize that words draw distinctions that are often completely arbitrary and do not reflect any fundamental physical distinctions, and will thus potentially be ill-suited to discussing phenomena near the boundaries of their arbitrarily-constructed and potentially overlapping definitions.

Re:Fuck the IAU (0)

Anonymous Coward | about 6 months ago | (#46849567)

This is pretty cold by even brown dwarf standards, for which there are not clear cut offs in the definition other than an abstract sense of being able to do something like DD fusion by not protium fusion. If it falls short of a brown dwarf, then it would not be a star, and many don't even consider brown dwarfs stars either, so this has nothing to do with crappy IAU planet definitions.

This likely was a member of a BINARY system that got ejected by gravitational interactions".

Yes, lets settle terminology dispute by instead making assumptions about the number of bodies in the system it came from.

Stupid question from a non-astronomer (3, Interesting)

IDtheTarget (1055608) | about 6 months ago | (#46848743)

Sorry for the double-post, didn't realize I wasn't logged in when I posted this previously

I keep hearing about "Dark Matter" as an explanation for how galaxies don't fly apart due to the force generated by their rotation, but I can't help thinking that all that mass we're looking for in galaxies could be stuff like this. Regular matter that just doesn't generate enough heat or light for us to have noticed prior to this.

Could the question of how galaxies rotate be answered by large quantities of objects such as these?

Re:Stupid question from a non-astronomer (0)

Anonymous Coward | about 6 months ago | (#46848803)

I think the issue though is the current model of str and planet formation don't leave enough time for trillions of these undetected brown dwarfs to exist to counteract the expansion of space, so it's not quite as simple as that

Re:Stupid question from a non-astronomer (5, Interesting)

aardvarkjoe (156801) | about 6 months ago | (#46848805)

The Wikipedia article on dark matter [wikipedia.org] discusses this in depth. Although I'm no astrophysicist and can't vouch for the article's accuracy, it does outline some of the reasons why those studying it believe that objects like this cannot account for the amount of dark matter required to explain how galaxies behave.

Re:Stupid question from a non-astronomer (5, Interesting)

idji (984038) | about 6 months ago | (#46848879)

Your question is whether Dark Matter could be real and observed MACHOs [wikipedia.org] .
The other main option is that Dark Matter could be hypothetical WIMPs [wikipedia.org]
Numerous experiments have ruled out MACHOS as making up the bulk of Dark Matter. The missing mass problem is not solved by MACHOs.
At the moment the WIMPS are beating the MACHOS.
See also History of the search for Dark Matter [wikipedia.org]

Re:Stupid question from a non-astronomer (0)

Anonymous Coward | about 6 months ago | (#46849219)

At the moment the WIMPS are beating the MACHOS.

I think it's time to call the police. We can't have this sort of hierarchy reversal in our society.

Wait, what?

Re:Stupid question from a non-astronomer (0)

Anonymous Coward | about 6 months ago | (#46849619)

Don't sweat it too much. *No one* knows how stuff works at a large distance anyway. So far, "Dark Matter" is nothing but invention of people's imagination. Same thing with "Dark Energy". The added these things to explain observations that do not seem to add up with our understanding of gravity.

1. there is "missing mass" on galactic scales, or otherwise galaxies would not rotate as they do, *and*
2. there is "negative energy" on universal scale or galaxy cluster would not be accelerating away from each other.

Personally, I do not believe in any of that crap until it is actually measured and quantified in a lab (or at very least, with direct observation). And if you say "no no, smart people's extrapolations are probably correct!" - the history of man's science is fraught with these "extrapolations being wrong". From initial ideas about electricity and magnetism (now knows as electromagnetism!), to why the sun was shinning (ie. nuclear? what nuclear? burning coal!) and to String Theory (not even wrong!), and now to the ideas about large scale forces we have no conceptual grasp of.

We don't even know how gravity is generated. This means Dark Matter/Energy are just hyperboles of people grasping at straws trying to make sense of unknowns the best they can. It does not mean they are wrong, but it also does not mean they are correct.

PS. Dark Matter is not just "not glowing matter", but also stuff that is thought not to interact with radiation so it is really invisible! Something like 70% of all matter in galaxy is suppose to be this weird "dark matter" with only 10-20% or so of it being composed of planets and brown dwarfs. As as I above, it is all assumptions on assumptions, with main assumption that there is only ONE long range force called gravity and that such a force is described by Newtons Laws - r^-2.

Re:Stupid question from a non-astronomer (1)

TrollstonButterbeans (2914995) | about 6 months ago | (#46851007)

And the "dark energy" only happens in between galaxies. Doesn't happen in our galaxy or our solar system or on our planet.

And who knows, maybe it is right --- then again you hit on the idea in the 1800s that the sun might be made of coal because we viewed coal as the most efficient fuel we could understand.

(I would almost swear you are copying me.)

Re:Stupid question from a non-astronomer (1)

radarskiy (2874255) | about 6 months ago | (#46850125)

These object are composed of ordinary every day matter so they interact with electromagnetic radiation. For instance, this particular object was detected by infrared radiation.

Observation of the rest of the universe shows more gravitational interaction than electromagnetic interaction versus what you would expect from ordinary matter. "Dark Matter" and "Dark Energy" are proposed particle types that do not interact electromagnetically but to interact with other forces. Other proposals model the forces differently so that ordinary matter could produce the observed effects.

Nibru is here (0)

Anonymous Coward | about 6 months ago | (#46848749)

planet x or the nibru is here....

Re:Nibru is here (0)

Anonymous Coward | about 6 months ago | (#46848843)

Yes, if by "here" you mean "7.2 light-years away."

-1 insensitive (0)

Anonymous Coward | about 6 months ago | (#46848765)

Headline is WAY offensive. Racist, sexist, and size-ist in the first three words!

Amasing! A Frigid Brown Dwarf? (1, Informative)

LifesABeach (234436) | about 6 months ago | (#46848777)

My personal experiences, have been very much, the opposite.

Re:Amasing! A Frigid Brown Dwarf? (2)

laejoh (648921) | about 6 months ago | (#46848971)

Ah, you met her too?

Kudos for saying Kelvin and not degrees Kelvin (1, Informative)

Quantum_Infinity (2038086) | about 6 months ago | (#46848811)

Kudos for writing 225-260 Kelvin and not 'degree Kelvin' or 'Kelvins' in the summary. Slate f'ed up though. They wrote 'Kelvins'. I have seen even reputable scientific writings using degrees prefix with Kelvin. It's very disheartening to see that even some scientists don't get it that you don't use degrees when talking about absolute temperature.

Re:Kudos for saying Kelvin and not degrees Kelvin (4, Informative)

Jeremy Erwin (2054) | about 6 months ago | (#46848935)

From an authoritative and current source [bipm.org]

It follows that the thermodynamic temperature of the triple point of water is exactly 273.16 kelvins, Ttpw = 273.16

If the BIPM can't be bothered,I don't see why the rest of us should follow your prescription.

Re:Kudos for saying Kelvin and not degrees Kelvin (2)

Jeremy Erwin (2054) | about 6 months ago | (#46848989)

And since

And to head off your objection.

Readers should note that the official record is always that of the French text.

The french standard says

Il en résulte que la température thermodynamique du point triple de l’eau est égale à 273,16 kelvins exactement, Ttpw = 273,16 K.

french original [bipm.org]

The first obligation of a pedant is to be technically correct.

Re:Kudos for saying Kelvin and not degrees Kelvin (0)

Anonymous Coward | about 6 months ago | (#46849159)

And since

And to head off your objection.

The first obligation of a pedant is to be technically correct.

Please, continue making an ass of yourself.

Re:Kudos for saying Kelvin and not degrees Kelvin (4, Informative)

AthanasiusKircher (1333179) | about 6 months ago | (#46849093)

Kudos for writing 225-260 Kelvin and not 'degree Kelvin' or 'Kelvins' in the summary. Slate f'ed up though. They wrote 'Kelvins'.

Umm, sorry, but you're wrong. As an SI unit, a "kelvin" (yes, with a lowercase k) is pluralized using the same grammatical rules as others (e.g., volts, ohms, etc.). Its abbreviation is an uppercase K.

So, "225-260 kelvins" or "225-260 K" is correct, according to official SI standard.

If you want to be pedantic, be sure you have a clue concerning what you're talking about.

(And regardless, I think this is a rather stupid thing to get too pedantic about. The previous standard, before 1968, referred to it as "degrees Kelvin" just like all the other temperature standards. I understand that the SI conventions are trying to maintain consistency across all units, but it's weird when that also results in breaking consistency with all other units that deal with the same type of measurement. I'm not saying it's wrong, and official scientific documents shoudl get it right, but in normal language... I think this is a rather silly think to get worried about, since it actually breaks other linguistic conventions of standard language.)

Re:Kudos for saying Kelvin and not degrees Kelvin (1)

AthanasiusKircher (1333179) | about 6 months ago | (#46849145)

And by the way, before somebody starts objecting to my comment about common language usage by saying that "kelvins" and not "degrees Kelvin" represents an absolute scale or something, rather than a "degree" -- that's a bogus argument. Anyone who works with "degrees Rankine" knows that (1) it's always Rankine, not rankine, (2) it's never pluralized as "rankines" as "kelvins" is, (3) the abbreviation should contain the degree symbol, and (4) the only people who say "Rankine" instead of "degrees Rankine" are the worst sort of ignorant pedants, like the OP, who think they are imitating the "correct" usage of "Kelvin" to refer to an absolute temperature scale, but actually aren't using it correctly (since, as I noted, "kelvins" should be lowercase and pluralized, as "rankines" never is.)

Dim stars and dim hopes (0)

Anonymous Coward | about 6 months ago | (#46848849)

Sigh... interstellar travel. Even if we solve the propulsion problem, there's another problem--uncharted objects like this. Yeah, the odds are low; but one brown dwarf in your way can spoil the whole day. Really though the big ones like this probably aren't so much the worry, as it is areas of space with slightly more than usual bullet-sized objects. I think any reasonable interstellar craft is going to have to be huge and have multiple airlocks.

Re:Dim stars and dim hopes (1)

tragedy (27079) | about 6 months ago | (#46849009)

I don't think brown dwarf stars are really going to be much of a problem. They're hard to spot when they're 7 light years away, but they're still really big objects that are highly likely to appear to be moving through space from the perspective of any interstellar craft. Any such craft can be expected to have telescopes and something like this is virtually certain to show up through the telescope occluding other objects when it's closer. At the kinds of distances where it would be obvious there's still plenty of time to make a tiny course correction which will allow the craft to dodge it entirely. Heck, you can still make such a course correction when it's close enough to spot by the naked eye as a hole in the field of stars.

So, unless the the interstellar craft is effectively just drifting blind, I'm going to have to conclude that objects like this are basically a 0% risk for a direct collision. The smaller objects you mention are definitely the only real risk.

Re:Dim stars and dim hopes (1)

SydShamino (547793) | about 6 months ago | (#46850521)

The Wikipedia article on rogue planets discusses ways in which they could retain an atmosphere, warmth, and liquid water. If we knew one of these was in the neighborhood, and knew it was going somewhere interesting, we could use it as a ship. It's possible that we could get to one in a few centuries of travel, and then perhaps colonize it, and ride it the rest of the way to our ultimate destination. That's assuming wherever the rogue planet was going was more interesting and/or less deadly than wherever Earth was going at the time.

Re:Dim stars and dim hopes (1)

Sperbels (1008585) | about 6 months ago | (#46851353)

Even if we solve the propulsion problem, there's another problem--uncharted objects like this.

If we could actually speed a ship up to anywhere near the speed of light, even hitting a pebble is likely to blow up your spaceship.

Nemesis Star (1)

Dukenukemx (1342047) | about 6 months ago | (#46848877)

Could it be the Nemesis Star that orbits the Sun from far away, and maybe responsible for periodic extinctions here on earth? Probably not. :)

A lot closer (0)

Anonymous Coward | about 6 months ago | (#46848889)

My girlfriend's anus meets these specs except she's only about 3 miles away.

Close is relative (1)

nbritton (823086) | about 6 months ago | (#46848931)

Traveling at 25 m/s, the speed of the current fastest man made object, it would take 55,885 years to reach this star. It's understandable why we haven't noticed it till now.

Re:Close is relative (1)

nbritton (823086) | about 6 months ago | (#46848943)

I meant to say 25 miles per second, which is about 11 m/s

Hey! (0)

Anonymous Coward | about 6 months ago | (#46848951)

Don't talk about my girlfriend that way!

Frigid Brown Dwarf Found Only 7.2 Light-Years Away (0)

Anonymous Coward | about 6 months ago | (#46849005)

They've found my ex-wife!

Perhaps a Dyson Sphere? (5, Interesting)

Lew Pitcher (68631) | about 6 months ago | (#46849133)

Two elements of TFA caught my eye:

  1. The object radiates at "around 225 – 260 Kelvins", or (if I got the math correct) 12.878971111111
    micrometers
  2. the object "has a very low mass, too, probably between 3 and 10 times the mass of Jupiter".

Together, these figures are within the range for a type I (or, maybe even a type II) Dyson sphere.
And, it is only 7.2 light years away?

Yes, it is very probably the Brown Dwarf that the astronomers think it is.
But, imagine. It could be a Dyson sphere; our first evidence of advanced life beyond the earth.

Re:Perhaps a Dyson Sphere? (1)

MichaelSmith (789609) | about 6 months ago | (#46849975)

I doubt it because we would be deluged with holidaying spherians every long weekend. Earth beaches are the best. Also the construction process would have generated a lot of debris. Seriously, it is too close not to be noticed as such. If they were humans there would be trillions of them in there. Even if it was a ringworld sort of thing with a collapsed civilisation, there would be ships coming past and making radio noise, exhaust, etc.

Re:Perhaps a Dyson Sphere? (1)

ltbarcly (398259) | about 6 months ago | (#46850447)

I doubt it because we would be deluged with holidaying spherians every long weekend. Earth beaches are the best. Also the construction process would have generated a lot of debris. Seriously, it is too close not to be noticed as such. If they were humans there would be trillions of them in there. Even if it was a ringworld sort of thing with a collapsed civilisation, there would be ships coming past and making radio noise, exhaust, etc.

Why do you think you have any idea what we would see or not see?

Imagine you were living with circa 1800 AD technology, and were looking for evidence of another civilization with circa 2014 technology. Keep in mind that this 200 year difference is nothing compared to the difference between modern technology and the technology of a race capable of building a Dyson sphere.

Perhaps you would use a rudimentary telescope to look out to sea. You would rule out any ships, since the weird objects you see don't have sails. If those giant things were ships, the sails would have to be miles across! So of course they are just some other phenomena, but they can't be ships.

Seeing a highway, you would know, obviously, that the things you saw weren't vehicles. Where are the horses? Plus, they are going far too fast. Besides, it couldn't be a road because there aren't any seams, and any road would have to be built from cobble stones. Clearly these are some other phenomena.

Besides, how could cities that far apart communicate effectively without Semaphore Towers? The lack of Semaphore Towers proves there is no way those big things on the horizon are cities. An envelope calculation shows that civilizations of that huge of a size would have to have at least 45000 semaphore towers between them just to negotiate the marriage of members of the royal families! http://en.wikipedia.org/wiki/S... [wikipedia.org]

Plus, if you have a Dyson Sphere, why would you need to send any ships anywhere? To trade? Trade what? Communicate? Why would you use a ship to communicate? If you did send ships, why would they go through our solar system?

Re:Perhaps a Dyson Sphere? (1)

MichaelSmith (789609) | about 6 months ago | (#46851023)

Imagine you were living with circa 1800 AD technology, and were looking for evidence of another civilization with circa 2014 technology. Keep in mind that this 200 year difference is nothing compared to the difference between modern technology and the technology of a race capable of building a Dyson sphere.

The existence of the advanced civilisation would be obvious to us because they'd be in our villages raping our women. So maybe aliens wouldn't be doing precisely that, but if they are anything like us they would be curious and hungry for resources.
I think the it is significant that the only debris found on the lunar surface was put there by humans. Any sort of exploration of our solar system would have left debris, garbage, broken vehicles, etc. And if somebody invested in a Dyson sphere only 7 light years away, they would be keeping an eye on us for sure.

Re:Perhaps a Dyson Sphere? (1)

bill_mcgonigle (4333) | about 6 months ago | (#46851267)

It might not be a Sphere itself, but my mind went there as well. If you have something 'refrigerator warm' in the middle of space, you can extract useful energy from it, and especially when the damn thing isn't on fire, materials. I'm thinking of some sort of sphere with millions of space elevators dangling down from the inside to the planet's surface, or something of that nature.

[insert hundreds of pages of math]

Perhaps a decent place for humans to do "My First Space Sphere" without all the stresses involved with a system-sized operation. Better get to work on those monoliths first, though - we'll have to build the sphere out of the planet's materials. We might have to send along the first elevator already made and lower the first factory down to the planet. I bet there's plenty of mass in orbit already for the counterbalance.

Re:Perhaps a Dyson Sphere? (1)

sillybilly (668960) | about 6 months ago | (#46851751)

A Dyson sphere might be radiating at 2.725 K, the microwave background temperature of the Universe, as the beings in it might have found a way to violate the 2nd law, via such things as a molecular ratchet, or brownian ratchet, and the Universe might be full of 2.725 K radiating things. The best way to hide a Dyson sphere is to make it the same temperature as the surroundings, and if it's not the same temperature, you may assume it's not a Dyson sphere.

As far as the warm temperature goes, we have to look at our own planet, and find out why the volcanic lava is hot, and it's because of K40 and U235 decay, and this goes for every massive object out there, including Jupiter and all the other planets, and this non-star.

As far as life beyond Earth is concerned, we think we know two things: it requires water in a liquid state, and be organic, carbon based, at least in its initial stages. Sufficiently advanced carbon might create self replicating silicon based life, robots enabled with artificial intelligence, not requiring any water or carbon to function, but in its formative stages we assume it would always be carbon based requiring liquid water. There are probably a gazillion places out there with liquid water - all you need is sufficient temperature, either from internal heat or from proximity to a star, or both, and sufficient gravity to hold the liquid water on the planet, and not let it evaporate and escape into outer space. The Earth might be at the low limit of the gravity range before water loss happens, but the high limit is probably very high, as ice becomes liquid under compression by a skate blade, and you need extraordinarily huge forces before it starts acting weird again, as a solid-like material, if it ever acts like one. I'm too lazy to look up these details right now, it's sufficient to say that life may be possible under huge gravity. Now gravity determines another important factor, and that is brain-size, as the sea has whales, but the land only has elephants as the biggest creatures, including brain size. Now brainsize alone is not a determining factor of intelligence, as there are many birds who can solve tasks that elephants and cows might have difficulty with, and we can explain that by interconnectedness principles - if you assume each connection between neurons to store 1 bit, instead of the neuron itself storing 1 bit, like cells on a chip or harddisk or cd presently do, out of 5 neurons, instead of 5 bits you can get the following combinations: 1, 2, 3, 4, 5, 12, 13, 14, 15, 23, 24, 25, 34, 35, 45, and also possibly 123, 124, 125, 134, 135, 234, etc and 1234, 1235, etc, with a lot more storage/processing space, if the combinatedness, connectedness is high. Building a neuron dendrite is costly, and probably each human neuron is not connected to 1 billion other neurons each, just, say 5 others, or 20 others, but an elephant might spend only on 5 dendrites, a bird might get 20, because a bird cannot afford to drag around a heavy brain while flying, but still needs a lot of visual processing power to see well from a distance. So size is not everything, but we can safely assume that a lifeform that's 10^-10 m size, or 1 angstrom size, or 0.1 nm, 0.0001 micrometer size does not exist, because that's the size of a single atom, and you gotta get more complicated than that to get life working. Also, while great buoyant lifeforms like octopuses and whales are possible floating in water, it is really difficult to develop things like metallurgy while immersed in water, and building of structures and using tools. Some octopuses will use tools, but pretty much all sea-life is a story of tiny fish being eaten by bigger fish being eaten by bigger fish being eaten by bigger fish, and not much else is going on, well, there are some mating rituals and dolphin communal gossiping, but having tentacles like humans do is a prerequisite to tool use. Even super-intelligent sea life might have a hard time with conducting chemical experiments, and modifying objects such as clothes, or weapons to hunt. So there is a thing with assuming life to be land based, and oxygen based, and under heavy gravity there is a severe limit on size, including brain size, which cannot be 1 angstrom size to work properly. So beings like tiny bugs might develop, but may not be intelligent enough until they develop a "hive mind," through telepathy of some kind of electromagnetic wifi between small brains, or even very slow speed of 0.000000001 Mhz equivalent processing power based on slow signal chemical odor transmission, but all of a sudden you have the benefits of distributed computing. Also, if space travel by sentient life is possible at all, then it might have happened already to this planet, way before mammals ever walked on the planet, let alone monkeys or apes like us humans did. I'm an ape. Represent.

Summary Incorrect (2)

iggymanz (596061) | about 6 months ago | (#46849225)

Brown dwarves are not stars, this astronomer did not find a star nor the 7th furthest star from the Sun. Brown dwarves are known as "sub-stellar objects". No fusion, no star.

Sorry, your age estimate must be wrong. (0)

Anonymous Coward | about 6 months ago | (#46849379)

I have been informed that this Brown Dwarf cannot be more than 6,000 years old. At least that is one "opinion" out there...

The real question is (0)

Anonymous Coward | about 6 months ago | (#46849857)

will it blend

Ejected? (1)

MichaelSmith (789609) | about 6 months ago | (#46849939)

it may have formed around a star like a planet does, then got ejected by gravitational interactions with other planets.

But if Jupiter interacts with anything, Jupiter isn't going to get ejected. The remaining object must have been a sizeable star.
This star must be warm deeper down. I wonder if it is a good place for life.

Re:Ejected? (0)

Anonymous Coward | about 6 months ago | (#46850151)

The atmospheric physics of these objects could be really interesting as they age.

It it's sorta-planetary in origin, maybe whatever carbon from any methane it picked up during formation hasn't all sunk down to the core. Maybe there's enough oxygen that didn't sink down to combine with the hydrogen to form clouds of water vapor, which then precipitate out over the eons.

There's no fixed surface, but deep down, you're talking metallic hydrogen and other weird stuff.

Has anyone modeled what happens to such an object over a 5-10 billion year timeframe? How long before everything condenses out? 10 billion years? 100? Or trillions?

Another crazy idea, although it's unlikely that moons would remain bound to it during the ejection process, it's concievable. We know that moons and tidal stress can create heat. If Jupiter's moons formed along with Jupiter, we know that it can take at least 5 billion years before the moons become tidally locked and freeze out.

Somewhere in the universe is a world like Krikkit, composed of creatures who live in the waters benath an ice-encrusted moon. As their scientists spend millennia developing the tech to dig upwards through progressively-colder layers of frozen water, methane, and ammonia, they finally break through to find a universe consisting of nothing more than a slowly cooling brown dwarf, and then one of them sees the sky for the first time, and utters the words "It'll have to go..."

Re:Ejected? (1)

MichaelSmith (789609) | about 6 months ago | (#46850189)

Yeah but that's Somebody Else's Problem.

Frigid Brown Dwarf! (1)

pablo_max (626328) | about 6 months ago | (#46851745)

That's amazing! That is the exact name I had for my ex wife!

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