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Frigid Brown Dwarf Found Only 7.2 Light-Years Away

Posted by Soulskill on from the interstellar-stalker-hiding-in-the-bushes dept.

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.'"

142 comments

  1. That's no moon. by Anonymous Coward · · Score: 0

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

    1. Re:That's no moon. by ShanghaiBill · · Score: 1

      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.

    2. Re:That's no moon. by SydShamino · · Score: 1

      http://en.wikipedia.org/wiki/R...

      Per the article, it could also be a "sub-brown dwarf".

      --
      It doesn't hurt to be nice.
    3. Re:That's no moon. by Anonymous Coward · · Score: 0

      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

    4. Re:That's no moon. by sillybilly · · Score: 1

      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.

    5. Re:That's no moon. by Cyberax · · Score: 1

      There are reasons to think that Jupiter's heat is sustained by simple gravitational collapse, as its core gets slowly transformed into metallic hydrogen.

    6. Re:That's no moon. by RockDoctor · · Score: 1

      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.

      Actually, probably not. There wasn't much potassium and uranium at the orbital position where proto-Jupiter formes, compared to water ice. So most models of the formation of Jupiter (and the rest of the Solar system) have a proto-Jupiter forming largely of water-ice, then going into runaway growth at about that mass and building up huge additional amounts of hydrogen and helium from the Solar nebula.

      Some models still have Jupiter collapsing from the crystallisation of metallic hydrogen in Jupiter's core, which releases heat (as says). Other models ahve that heat generated because of the gravitational settling of helium into Jupiter's core (rather analogous to the settling of iron into the Earth's core). And it's possible that both processes are going on ; we don't know the equations of state of hydrogen and helium well enough at these pressures to be really sure.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    7. Re:That's no moon. by sillybilly · · Score: 1

      Wikipedia geothermal_gradient#Heat_Sources, http://en.wikipedia.org/wiki/G... says the top heat producer on Earth is
      Th232 3.27 × 10^-12 W/kg mantle, then
      U238 2.91 × 10^-12 , and only then
      K40 1.08 × 10^-12, and then
      U235 0.125 × 10^-12.

  2. close enough to mine by Anonymous Coward · · Score: 0

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

    1. Re:close enough to mine by Immerman · · Score: 2

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

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    2. Re:close enough to mine by HiThere · · Score: 1

      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.)

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    3. Re:close enough to mine by Anonymous Coward · · Score: 0

      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.

    4. Re:close enough to mine by Immerman · · Score: 1

      Talk about a killer commute...

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    5. Re:close enough to mine by Immerman · · Score: 1

      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.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    6. Re:close enough to mine by Wycliffe · · Score: 2

      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.

    7. Re:close enough to mine by Anonymous Coward · · Score: 0

      Except that both of those forms, if allowed by GR, would still allow for time travel and problems with causality. And that "if allowed" is a big if, considering how much stuff GR is throwing in the way even if ignoring requirement of unknown forms of matter, e.g. filling a warp bubble with intense radiation at speeds approaching c.

    8. Re:close enough to mine by Immerman · · Score: 1

      AC is correct, both of those forms do still allow at the very least communication with the past if employed in a larger construct. Basically in the simplest form it relies on the fact that at relativistic speeds the Lorentz transformation rotates the space-time axes such that if some sublight traveler is moving at relativistic speeds relative to Earth, then certain directions that they perceive as space will be perceived by us as time. An FTL traveler departing from that relativistic frame can then travel along those spatial directions fast enough to travel into what we perceive as the past. With a cleverly constructed FTL communication loop between two frames of reference traveling at relativistic speeds relative to each other, you can then easily transfer information from one frame into it's own past.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    9. Re:close enough to mine by NemoinSpace · · Score: 1

      Considering we've given these guys the rest of eternity you'd think they would visit once in a while? They don't even write.

    10. Re:close enough to mine by Immerman · · Score: 1

      It's your own fault for not reading the flyers. They're going to throw a big bash downtown yesterday, you should come.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  3. It might be a planet by rossdee · · Score: 2

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

    1. Re:It might be a planet by olsmeister · · Score: 5, Informative

      That would make it a rogue planet.

    2. Re:It might be a planet by idji · · Score: 2

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

    3. Re:It might be a planet by FatLittleMonkey · · Score: 1

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

      If you're gonna be pedantic, be pedantic.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
  4. Nearest Star? by Anonymous Coward · · Score: 0

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

    1. Re:Nearest Star? by Anonymous Coward · · Score: 1

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

      Damn your reading comprehension sucks.

    2. Re:Nearest Star? by davester666 · · Score: 1

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

      --
      Sleep your way to a whiter smile...date a dentist!
    3. Re:Nearest Star? by davester666 · · Score: 0

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

      --
      Sleep your way to a whiter smile...date a dentist!
    4. Re:Nearest Star? by radiumsoup · · Score: 1

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

    5. Re:Nearest Star? by K.+S.+Kyosuke · · Score: 1

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

      --
      Ezekiel 23:20
    6. Re:Nearest Star? by davester666 · · Score: 1

      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.

      --
      Sleep your way to a whiter smile...date a dentist!
    7. Re:Nearest Star? by Anonymous Coward · · Score: 1

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

    8. Re:Nearest Star? by davester666 · · Score: 1

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

      --
      Sleep your way to a whiter smile...date a dentist!
    9. Re:Nearest Star? by Anonymous Coward · · Score: 3, Informative

      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).

    10. Re:Nearest Star? by TapeCutter · · Score: 1

      You obviously haven't tried to hide something from a 2yo.

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    11. Re:Nearest Star? by Anonymous Coward · · Score: 0

      K. S. Kyosuke: You've been called out (for tossing names) & you ran "forrest" from a fair challenge http://slashdot.org/comments.p...

  5. How could it exist for so long without us knowing? by Viol8 · · Score: 4, Insightful

    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.

  6. Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 2, Interesting

    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?

    1. Re:Okay, stupid question from a non-astronomer... by Blaskowicz · · Score: 5, Informative

      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.

    2. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 0

      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.

    3. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 0

      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.

    4. Re:Okay, stupid question from a non-astronomer... by Immerman · · Score: 1

      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.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    5. Re:Okay, stupid question from a non-astronomer... by Jeremy+Erwin · · Score: 1

      this 2010 preprint 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.

    6. Re:Okay, stupid question from a non-astronomer... by Electricity+Likes+Me · · Score: 2

      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).

    7. Re:Okay, stupid question from a non-astronomer... by Electricity+Likes+Me · · Score: 1

      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?

    8. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 2, Informative

      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.

    9. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 0

      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?

    10. Re:Okay, stupid question from a non-astronomer... by Electricity+Likes+Me · · Score: 1

      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).

    11. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 1

      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...

    12. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 1

      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.

    13. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 1

      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.

    14. Re:Okay, stupid question from a non-astronomer... by TrollstonButterbeans · · Score: 1, Interesting

      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.

      --
      Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
    15. Re:Okay, stupid question from a non-astronomer... by Immerman · · Score: 1

      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.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    16. Re:Okay, stupid question from a non-astronomer... by Sperbels · · Score: 1

      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.

    17. Re:Okay, stupid question from a non-astronomer... by FatLittleMonkey · · Score: 1

      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.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
    18. Re:Okay, stupid question from a non-astronomer... by cusco · · Score: 1

      Then how do they get there? For that matter, how do they stay there? Any gravitational interaction strong enough to toss them out of the galactic disk should be easily observable, and any orbital path around the center of the galactic mass should bring them back into the disk fairly frequently.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    19. Re:Okay, stupid question from a non-astronomer... by scarboni888 · · Score: 1

      I totally agree with you. I mean - here's the thing that's always bothered me - if there is SO MUCH F-ing dark matter and dark energy then how is it so mysteriously EVERYWHERE ELSE in the universe but not anywhere near here? If the universe has been permeated by so much of this stuff there's no reason to believe it doesn not permeate our local little section of that universe is there?

      This is why I'm with you: "dark matter" and "dark energy" are really just placeholders signifiying our model of astrophysics is less than complete and correct.

      I'd say we're at least as far away from understanding physics properly as newtownian physics is from general relativity. And most likely even more far away than that.

      And that's ok: it's part of learning. But don't try to buffalo us with some made up crap that is everywhere in the universe but not here. That starts to sound like 'god' to me. I thought scienctists had more humility than that?

    20. Re:Okay, stupid question from a non-astronomer... by Immerman · · Score: 1

      Why do you assume they didn't form there? At one point the entire galaxy was one big gaseous disc. Smaller eddies then formed within he disc to form proto-stellar discs that eventually became stars, just as eddies within those stellar discs eventually became planets. Stellar discs that formed in the thinner outer reaches of the galactic disc would presumably contain less mass and end up forming smaller bodies that were still in a basically circular orbit around the galactic hub. They'd never get appreciably closer to the galactic hub than they are now, and would quite likely be essentially pure hydrogen. First-generation "stars" that never had enough mass to fuse into more massive elements.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    21. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 0

      I totally agree with you. I mean - here's the thing that's always bothered me - if there is SO MUCH F-ing dark matter and dark energy then how is it so mysteriously EVERYWHERE ELSE in the universe but not anywhere near here? If the universe has been permeated by so much of this stuff there's no reason to believe it doesn not permeate our local little section of that universe is there?

      Except who said it isn't here? Pretty much every theory and model says it does permeate the solar system, which is the basis of many particle based searches for dark matter with detectors. The densities and distributions needed to fit observations about galaxies would be too small to have any noticeable internal gravitational effect on the solar system with current measuring techniques.

    22. Re:Okay, stupid question from a non-astronomer... by RockDoctor · · Score: 1

      As for where they are, how about the outside rim of the galaxy?

      The mathematics of Newtonian gravity require the invisible gravitating mass to be inside the radius of the (excessibely rapidly) orbiting outer stars.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    23. Re:Okay, stupid question from a non-astronomer... by RockDoctor · · Score: 1

      You're assuming these transits would occur frequently and that we actually have the equipment pointed at the sky to detect them.

      Which parts of the MACHO theory and experiments didn't you understand? The ones that said "it's the late 1980s, and we've been running these observational programmes for several years and we're not seeing enough interactions to explain the gravitating mass that we know needs to be there"? Or the ones that said "it's the mid-1990s, and we're still not seeing enough interactions, but we have seen what appears to be two mutually-orbiting bodies transit a halo star"? Or the ones that said "it's the late 1990s and the several different MACHO programmes appear to be far below the detection rate that would be necessary to explain the observed rotation profiles"?

      I was reading those reports in the science press through those times. Weren't you?

      The observed rates of MACHO detection (by microlensing, particularly, because that was easiest) were far too low to account for the "missing miss". So people stopped trying to solve the missing mass problem by going down that route.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    24. Re:Okay, stupid question from a non-astronomer... by Immerman · · Score: 1

      Actually, no. If the majority of mass is within the radius of the outside stars then they would be rotating more slowly than the inner stars. If instead you have the bulk of the mass of the galaxy distributed outside the visible galactic rim then you have a situation where the visible "spokes" of the "bicycle wheel" will more closely match speed with the invisible "tire", regardless of their distance from the hub. Which is exactly the situation we're seeing.

      Besides which we *know* Newtonian gravity is deeply flawed outside the most trivial applications, so using it in any large-scale analysis is patently ridiculous, especially when the same analysis has been done with a more modern theory and the resulting prediction far more closely matches the observed reality.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    25. Re:Okay, stupid question from a non-astronomer... by Electricity+Likes+Me · · Score: 1

      Again: you're proposing that somehow, 96% of the mass of the universe is in unseen brown dwarfs that are all floating around the edge of the galactic disk.

      That is a huge amount of mass, to the point that it would be more significant then all the other mass in the galaxy. If this mass is not evenly distributed, then it would both form a binary system with the galaxy, and also promptly start collapsing itself into actual stars and a much denser body.

      If it's evenly distributed, you still have to answer the question of how it stays that way, since you can't hand-wave billions of years of stellar interactions as "hydrogen doesn't interact very much". Well, yes it does, that's why we have stars in the first place. In fact it's why galaxies aggregate into disks and not spheres in the first place - because in 3-dimensional space collisions are much more likely then if everything is moving in roughly the same direction.

      And of course you can't explain the observational problem: if this is what happened it would be really obvious from gravitational lensing experiments - we'd see a very tight cylindrically aberrated lens when observing other galaxies side on. But we don't - we see an approximately spherical halo of dark matter which resists aggregation because it doesn't interact with itself.

    26. Re:Okay, stupid question from a non-astronomer... by Electricity+Likes+Me · · Score: 1

      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.

      Here's the problem: you can't argue collisions would be rare. Collisions in the accretion disk of a gravitational body are extremely rare, but an object like a black hole is very bright because over the life time of the universe that's still a lot of collisions relatively.

      The issue is, you're adding 200 times the number of entities and really underestimating that value, that's 200 brown dawrfs, larger then Jupiter, within the local neighborhood of Sol alone, along with another 400-600 around Alpha Centauri, 4 light years away. So 600 brown dwarfs, that we somehow have never discovered, sitting somewhere - generously - in the range of ~10 light years of Sol.

      And this article, the article we're talking about, is discussing how we've just discovered 1 7 light years away. 1, since we've been observing the sky. Now, it's a hard problem, but, 1? Out of almost 1000 that people are arguing should be there?

    27. Re:Okay, stupid question from a non-astronomer... by Immerman · · Score: 1

      Okay, I'm not actually specifically arguing against the existence of Dark Matter, simply pointing out that one of the major anomalies that led us to initially speculate that it existed - anomalous galactic revolution - has been largely explained with modern conventional physics. Supplement GR with a relatively small number of nonluminous halo objects and you can completely explain galactic rotation without increasing galactic mass 20-fold. And there's no particular reason to assume that collisions between sub-dwarfs would be any more common in the thin outer halo than in the visible disk. In fact if the material were spread out thin enough that full-sized stars rarely formed, then you might well expect that the density of sub-stars in the halo is lower than within the disc. It's even possible that once upon a time the halo was full of stars, which lived out their lives and eventually collapsed into white dwarfs and neutron stars which since collapsed into white dwarfs and neutron stars that have radiated away enough of their residual thermal energy that they can't be seen over the glow of the living stars. If the outer gas clouds were thin to begin with then the resulting explosive nebulae would be even thinner, and after a stellar generation or two there might well no longer be dense enough gaseous material to form new stars.

      That doesn't mean DM doesn't exist - there is other evidence that something strange is going on: The gravitational lensing you mention, especially with respect to the bullet cluster. The distribution of visible galaxies in the universe, and I think even aspects of the cosmic microwave background radiation all suggest something odd is going on. But the single strongest evidence that launched the idea in the first place no longer applies, and perhaps it's time to reconsider the explanations for other observations in light of that fact. Especially since all attempts so far to detect the DM that should be passing through us right now have come up negative. There's also the fact that much of the remaining evidence we have for DM relies on theories of the early formation of the universe, something where the accepted description itself depends on the non-predictive theory of inflationary energy, whose logical consequences is that the entire observable universe exists within a single bubble in an effectively infinite expanse of inflationary energy that should even now be multiplying at far greater than lightspeed, creating fresh inflationary energy from the empty space into which it expands, and creating bubbles of mass and energy whereever it begins to decay*, but the physical laws of each bubble should logically be different than those within our own, as the separation of forces occurs during the decay period. From a scientific perspective a theory whose logical consequence is that "everything theoretically possible is currently happening" is only marginally better than "god did it".

      *IIRC in order to comply with observed reality the inflationary energy would have to have an incredibly short half-life, but would also have to replicate so quickly that it could never decay completely. In the time it takes for half a given volume to decay into "normal" mass-energy, the other half would have replicated many, many times more inflationary energy than there was to begin with as it separates empty space into positive inflationary energy and the exactly equal negative gravitational energy associated with it.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    28. Re:Okay, stupid question from a non-astronomer... by Sperbels · · Score: 1

      What part of my last sentence didn't you read?

    29. Re:Okay, stupid question from a non-astronomer... by Anonymous Coward · · Score: 0

      Search a little longer on Google. There are some good calculations out there on how much dark matter must be in the Solar System to be in accordance with current dark matter theories and it is ... not much. Actually it would be such a minute amount that it is could never be detected by its gravitational effects with current technology.

      And before you say: "Hold on, there's supposed to be more matter than dark matter in the Universe!" you have to consider that dark matter is pretty much spread out through the whole galaxy. This means, it is spread more or less evenly through all the "empty" space between the galaxy's stars -- and there is a whole lot more of that empty space than there are star systems.

      Since DM interacts only through gravity, dark matter falling into the gravity well of the sun does not hang around, but just gains kinetic energy and leaves again at the speed it came, hence no accretion of dark matter in the solar system -- it stays as diluted as it is.

      So just think a little longer before calling something "made up crap". Chances are, smarter people than you have spent a lot more time trying to figure this out ...

    30. Re:Okay, stupid question from a non-astronomer... by Neil+Boekend · · Score: 1

      It may permeate us. We just don't know.
      If dark matter is really not interacting with anything except that it causes gravity, how would we know? The stuff could be spread out so much between the stars that it is at a not-measurable density.
      Normal matter tends to clump together due to gravity. What if dark matter doesn't do that? We just don't know.

      Having said that: I don't like dark matter and dark energy either. I just don't have enough data to dispute it.

      --
      Well, I might have a way, but it only works on a semi spherical planet in a vacuum.
  7. Age range? by Anonymous Coward · · Score: 4, Insightful

    "...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.

    1. Re:Age range? by Anonymous Coward · · Score: 1

      Observed star ages span ~6 orders of magnitudes, so on a log-scale it's not that bad. (Some stars are only a few thousand years old in Orion Molecular Cloud Complex.)

  8. So this is Planet X? by Anonymous Coward · · Score: 0

    How long until it makes it here?

    1. Re:So this is Planet X? by Immerman · · Score: 2

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

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    2. Re:So this is Planet X? by Streetlight · · Score: 1

      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.

      --
      In a time of universal deceit, telling the truth is a revolutionary act. George Orwell
    3. Re:So this is Planet X? by Immerman · · Score: 1

      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.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    4. Re:So this is Planet X? by Thiez · · Score: 1

      Since the sun gets about 10% brighter every billion years we'll be dead long before either of those things happen.

    5. Re:So this is Planet X? by Immerman · · Score: 1

      True, but that's a separate issue from our sun exploding into a red giant. And really, both problems have the same relatively simple solution - move the Earth. It should be possible to start the process even with technology currently being developed - fusion-powered ion drives on the moon could slowly tug the Earth further from the sun. Sure it'd be incredibly slow, but we've got billions of years to get the job done. If we eventually master mass-energy conversion (a domesticated black hole should do the job nicely) then we'll have effectively unlimited energy to work with - more than enough mass on the moon to raise the Earth's orbit arbitrarily. In fact throw some massive lights on the near side to mimic sunlight and we could fly the whole planet between stars. Might want to grab a couple extra moons on our way the way out of the system just as backup batteries though. Maybe snare the other rocky planets as well - no sense leaving them to be devoured. Then again by that point they'll probably have been moved to more favorable orbits and colonized, and may well want to set of in their own directions.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  9. Fuck the IAU by l0ungeb0y · · Score: 0

    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.

    1. Re:Fuck the IAU by Immerman · · Score: 1

      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.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    2. Re:Fuck the IAU by Anonymous Coward · · Score: 0

      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.

  10. Stupid question from a non-astronomer by IDtheTarget · · Score: 3, Interesting

    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?

    1. Re:Stupid question from a non-astronomer by Anonymous Coward · · Score: 0

      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

    2. Re:Stupid question from a non-astronomer by aardvarkjoe · · Score: 5, Interesting

      The Wikipedia article on dark matter 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.

      --

      How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
    3. Re:Stupid question from a non-astronomer by idji · · Score: 5, Interesting

      Your question is whether Dark Matter could be real and observed MACHOs.
      The other main option is that Dark Matter could be hypothetical WIMPs
      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

    4. Re:Stupid question from a non-astronomer by Anonymous Coward · · Score: 0

      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?

    5. Re:Stupid question from a non-astronomer by Anonymous Coward · · Score: 0

      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.

    6. Re:Stupid question from a non-astronomer by radarskiy · · Score: 1

      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.

    7. Re:Stupid question from a non-astronomer by TrollstonButterbeans · · Score: 1

      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.)

      --
      Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
    8. Re:Stupid question from a non-astronomer by LongearedBat · · Score: 1

      What's kept in the dark is that, in this kind of matter, nerds rule!

    9. Re:Stupid question from a non-astronomer by Anonymous Coward · · Score: 0

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

      Theories about dark energy don't say such a thing, they suggests it exists everywhere, but the effects would only be seen over large distances. Complaining it can't be seen on small scales would be like complaining gravity doesn't exist because we can't measure it between two individual atoms in a lab.

  11. Nibru is here by Anonymous Coward · · Score: 0

    planet x or the nibru is here....

    1. Re:Nibru is here by Anonymous Coward · · Score: 0

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

  12. -1 insensitive by Anonymous Coward · · Score: 0

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

  13. Re:Frigid Brown Dwarf by ControlsGeek · · Score: 0

    I knew a girl like that once.

  14. Amasing! A Frigid Brown Dwarf? by LifesABeach · · Score: 1, Informative

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

    1. Re:Amasing! A Frigid Brown Dwarf? by laejoh · · Score: 2

      Ah, you met her too?

  15. Kudos for saying Kelvin and not degrees Kelvin by Quantum_Infinity · · Score: 1, Informative

    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.

    1. Re:Kudos for saying Kelvin and not degrees Kelvin by Jeremy+Erwin · · Score: 4, Informative

      From an authoritative and current source

      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.

    2. Re:Kudos for saying Kelvin and not degrees Kelvin by Jeremy+Erwin · · Score: 2

      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

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

    3. Re:Kudos for saying Kelvin and not degrees Kelvin by AthanasiusKircher · · Score: 4, Informative

      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.)

    4. Re:Kudos for saying Kelvin and not degrees Kelvin by AthanasiusKircher · · Score: 1

      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.)

    5. Re:Kudos for saying Kelvin and not degrees Kelvin by Anonymous Coward · · Score: 0

      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.

    6. Re:Kudos for saying Kelvin and not degrees Kelvin by Anonymous Coward · · Score: 0

      Look, the French can't even spell potatoe. And they are worse than the U.S. if you are counting on them to back you up in a fight.

  16. Dim stars and dim hopes by Anonymous Coward · · Score: 0

    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.

    1. Re:Dim stars and dim hopes by tragedy · · Score: 1

      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.

    2. Re:Dim stars and dim hopes by SydShamino · · Score: 1

      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.

      --
      It doesn't hurt to be nice.
    3. Re:Dim stars and dim hopes by Sperbels · · Score: 1

      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.

    4. Re:Dim stars and dim hopes by wierd_w · · Score: 1

      If this were an object that coalesced away from any (other) protostellar discs, it may conceivably have small objects orbiting it. Since there wouldnt have been a "fusion event" to blow away the remaining gas and dust of the original cloud it formed from, any objects that coalesced near to the central sub-brown dwarf would not have been pushed out by the radiation pressure.

      This means that gravitationally bound satellites close enough to be quite warm indeed just from tidal heating could be possible with "object systems" like this. (With small objects orbiting large ones at close distances, the odds of the objects being tidally locked increases greatly. However, without the sudden application of solar wind gusting through the accretion disc, the number of small rocky bodies would be much higher, meaning orbital resonances could help prevent this tide locking, should a sufficient number of such objects be at work-- planetoids with lots of "comparitively large moons" tugging on the planetoid's centers of mass, preventing tide locking.)

      The compact size of this dense object may suggest that the object is metal rich. That would indicate a reasonable probability for rocky terrestrial type objects orbiting it.

      Discounting the system as being too cold for life as we know it is premature. Tidally heated satellites with liquid oceans are possible, even with this very dark "star" overhead. (EG, look at Io around jupiter. Despite being waaay more than 1AU from the sun, the surface is totally motlen rock. Jupiter is smaller/lighter than this object.)

      Being a non-fusing object, this object can theoretically last for hundreds of billions of years-- much longer than our sun will live. If I were a member of an interstellar capable species looking for a "Long term solution", I would be very interested in systems like this one, and in red dwarf systems for this very reason. Artificial biospheres powered by thermal energy equilibrium (which itself is generated by gravitational tidal forces and radio-isotope decay) exploitation would be just as comfy for energy hungry lifeforms as a sunny planet like earth-- and be far more abundant for possible building sites.

      I find it highly foolish to just write off systems like this one as being "too cold for life".

    5. Re:Dim stars and dim hopes by Anonymous Coward · · Score: 0

      The compact size of this dense object may suggest that the object is metal rich. That would indicate a reasonable probability for rocky terrestrial type objects orbiting it.

      There is nothing so far to suggest this object is compact or metal rich. Early photometry work in the paper gives agreement with quite a few different models of brown dwarfs or large gas giants. Spectroscopic data might have to wait until the James Webb telescope due to how dim the source is.

      Even if assuming it had some substantial solid part, as otherwise tidal heating would be really inefficient, if its main source of heating was from tidal heating, you would have some trouble sustaining significant amounts of that on the parent body for long. Even if it had a "moon" with the mass of Jupiter at a distance of one of Jupiter's moon's, the entire gravitational and kinetic energy within that Jupiter sized moon would not be enough to sustain ~250 K emissions from the parent body for a billion years. Radioactive decay would only contribute about less than 1% of the heat it is radiating unless it had proportionately orders of magnitude more long lived radioactive material than the Earth and Solar system ended up with. The only sources that can sustain that heat for a long time that we know of are slow gravitational collapse/relaxation, and fusion (even if just deuterium fusion).

      Since there wouldnt have been a "fusion event" to blow away the remaining gas and dust of the original cloud it formed from, any objects that coalesced near to the central sub-brown dwarf would not have been pushed out by the radiation pressure.

      Gas can be blown off easily by other near by stars, for distances over many light years.

    6. Re:Dim stars and dim hopes by wierd_w · · Score: 1

      The idea here was NOT that the central object needs to be hot.

      The idea was that if it is metal rich, then the chances of rocky bodies that are much smaller/less dense than it can be tidally heated, and with that tidal heating, be able to support life. (say, chemotrophic microbes.)

      Spectroscopic analysis of the object will only reveal its atmospheric composition. Lensing analysis (from a transit) would better refine mass estimates, which could help refine the internal composition, but much like our own gas giants much closer by, we can only speculate as to what is deep below the clouds.

      Detecting orbiting bodies in this system is a non-starter with current technology, because the parent object is too dim to do effective transit light dimming measurements. The whole system would have to transit a very bright and distant system, and then if there are any large transiting objects in that distant system, interval periodicity will be suspect/difficult to refine.

      I still hold that systems like this one should be of considerable interest, and not passively written off as "too cold."

  17. Nemesis Star by Dukenukemx · · Score: 1

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

  18. A lot closer by Anonymous Coward · · Score: 0

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

  19. Re:Frigid Brown Dwarf by turkeydance · · Score: 5, Funny

    Google that without SafeSearch. ewwww.

  20. Close is relative by nbritton · · Score: 1

    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.

    1. Re:Close is relative by nbritton · · Score: 1

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

  21. Hey! by Anonymous Coward · · Score: 0

    Don't talk about my girlfriend that way!

  22. Frigid Brown Dwarf Found Only 7.2 Light-Years Away by Anonymous Coward · · Score: 0

    They've found my ex-wife!

  23. Perhaps a Dyson Sphere? by Lew+Pitcher · · Score: 5, Interesting

    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.

    --

    "values of beta will give rise to dom!"

    1. Re:Perhaps a Dyson Sphere? by MichaelSmith · · Score: 1

      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.

      --
      http://michaelsmith.id.au
    2. Re:Perhaps a Dyson Sphere? by ltbarcly · · Score: 1

      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...

      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?

    3. Re:Perhaps a Dyson Sphere? by MichaelSmith · · Score: 1

      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.

      --
      http://michaelsmith.id.au
    4. Re:Perhaps a Dyson Sphere? by bill_mcgonigle · · Score: 1

      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.

      --
      My God, it's Full of Source!
      OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
    5. Re:Perhaps a Dyson Sphere? by sillybilly · · Score: 1

      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

    6. Re:Perhaps a Dyson Sphere? by sillybilly · · Score: 1

      Also life even on this planet does not require a star, or light and photosynthesis, just a sufficiently high head, or "waterfall" of caloric, i.e. a large temperature gradient. See the Wikipedia page on Hydrothermal vent, http://en.wikipedia.org/wiki/H....

    7. Re:Perhaps a Dyson Sphere? by Anonymous Coward · · Score: 0

      No

    8. Re:Perhaps a Dyson Sphere? by iggymanz · · Score: 1

      the ratchets have been proven to be ineffective by Feynman for escaping the second law, they won't work as posited.

      Saying all life must follow some guidelines based on earth's composition or common factor of its life forms is using a sample size of one.

    9. Re:Perhaps a Dyson Sphere? by Neil+Boekend · · Score: 1

      It can't be a Dyson sphere because it is not big enough to encompass a star.
      It could theoretically be an artificially made object of similar properties. However, that is IMHO less likely than an ancient brown dwarf or a rogue planet.

      --
      Well, I might have a way, but it only works on a semi spherical planet in a vacuum.
  24. Summary Incorrect by iggymanz · · Score: 2

    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.

  25. Sorry, your age estimate must be wrong. by Anonymous Coward · · Score: 0

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

  26. Re:Frigid Brown Dwarf by Anonymous Coward · · Score: 0

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

    You insensitive clod!

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

  27. The real question is by Anonymous Coward · · Score: 0

    will it blend

  28. Ejected? by MichaelSmith · · Score: 1

    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.

    --
    http://michaelsmith.id.au
    1. Re:Ejected? by Anonymous Coward · · Score: 0
      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..."

    2. Re:Ejected? by MichaelSmith · · Score: 1

      Yeah but that's Somebody Else's Problem.

      --
      http://michaelsmith.id.au
  29. Re:How could it exist for so long without us knowi by Anonymous Coward · · Score: 0

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

  30. Frigid Brown Dwarf! by pablo_max · · Score: 1

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

  31. Could life exist on it? Yes. by fygment · · Score: 1

    If this is correct, then why not.

    --
    "Consensus" in science is _always_ a political construct.
  32. New Name by superid · · Score: 1

    A cold brown dwarf star?
    Did they name it "Gary Coleman"?

  33. Frigid Brown Dwarf by Anonymous Coward · · Score: 0

    Is that a celestial body, or a short radical feminist with a sun tan?

  34. Sounds like a loser star to me by scarboni888 · · Score: 1

    I say we completely ignore it from now it it's not really worthy of our attentions is it within its' rotten miserable failure to be anything important?

    1. Re:Sounds like a loser star to me by Neil+Boekend · · Score: 1

      You might think differently once your ramscoop collides with it because you chose to try to ignore it.

      --
      Well, I might have a way, but it only works on a semi spherical planet in a vacuum.
  35. Re:Frigid Brown Dwarf by JasonGoatcher · · Score: 1

    How about "Frigid brown dwarf revolves around hot star," is it porn or astronomy?

  36. ok stupid question(s) by Anonymous Coward · · Score: 0

    so in that solar system what makes that planet-star cold when the others are room temp. oh and would it make sence if the plant wasn't formed like a star or a plantet but something different like if it formed like the hypothesis that was proven wrong about how the moon was formed