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

Posted by Unknown on from the a-bit-chilly dept.

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

17 of 85 comments (clear)

  1. Is this the missing "dark matter"? by Anonymous Coward · · Score: 2, Insightful

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

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

    1. Re:Is this the missing "dark matter"? by mister_playboy · · Score: 5, Informative

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

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

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

      --
      Do what thou wilt shall be the whole of the Law ::: Love is the law, love under will
    2. Re:Is this the missing "dark matter"? by Anonymous Coward · · Score: 2, Informative

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

    3. Re:Is this the missing "dark matter"? by Buggz · · Score: 5, Insightful

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

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

    4. Re:Is this the missing "dark matter"? by TapeCutter · · Score: 4, Interesting

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

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

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    5. Re:Is this the missing "dark matter"? by joe_frisch · · Score: 4, Informative

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

    6. Re:Is this the missing "dark matter"? by idji · · Score: 2

      No, MACHOs do not account for all the Dark Matter in the Universe.

    7. Re:Is this the missing "dark matter"? by Charliemopps · · Score: 2

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

    8. Re:Is this the missing "dark matter"? by Anonymous Coward · · Score: 2, Insightful

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

    9. Re:Is this the missing "dark matter"? by mod+prime · · Score: 2

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

  2. First non-cloud candidate by mdsolar · · Score: 3, Interesting

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

  3. Occam's razor. by TapeCutter · · Score: 3, Insightful

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

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

    --
    And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    1. Re:Occam's razor. by idji · · Score: 3, Interesting

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

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

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

    2. Re:Occam's razor. by TapeCutter · · Score: 2

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

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    3. Re:Occam's razor. by TapeCutter · · Score: 3, Insightful

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

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

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
  4. Re:The theorized nemesis star? by Overzeetop · · Score: 3, Interesting

    The brown dwarf that orbits the sun is called Jupiter.

    --
    Is it just my observation, or are there way too many stupid people in the world?
  5. Re:Moons? by Rei · · Score: 3, Informative

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

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    Could chocolate let me finish?