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Death Star Caught In Act, All Wet

Posted by timothy on from the last-words-of-a-star dept.

NaturePhotog writes: "No, it's not CNN bad-mouthing the Empire's latest creation, it's astronomers catching a dying star in the act of becoming a nebula. Radio waves emitted by water molecules helped provide the age of the event."

14 comments

  1. That's no nebula! by Anonymous Coward · · Score: 1, Funny

    *sigh* Kids these days with their Hairy Porter... Never understand what *real* movies are about.

  2. Water molecules? by Dief_76 · · Score: 1

    How can water molecules exist in space?

    If they're too close to the source of the nebula, they'd be vaporised. Too far away, and they'd be ice.

    Does anyone have a better explanation of this than the one-line quote in the article?

    1. Re:Water molecules? by Anonymous Coward · · Score: 0

      Water vapor is made of water molecules.

      Ice is made of water molecules.

      Water molecules that exist in space are still water molecules.

    2. Re:Water molecules? by CheshireCatCO · · Score: 2, Interesting

      Actually, it is all probably in vapor form. It's hard to make ices in most of space, since it is rare that molecules come together to make a crystall.

      Water will not exist as a liquid in space, basically for the reasons you cite (plus, with effectively zero pressure, the water will just evaporte pretty quickly). But water vapor can exist inside the clouds of other gases, particular atomic hydrogen. Water, being such a great absorber and emitter of radiation, is really easy to spot, so we talk about it a lot.

    3. Re:Water molecules? by wnknisely · · Score: 2

      As the other comment in this thread noted, the water molecules detected are definately in the vapor phase, especially in a planetary nebula of this age (...still very hot). Vaporized water is still water.

      Assuming this is a medium mass main sequence star (and it should be to have this behavior at the end of its life) this is the final stage where it is sloughing off its outer atmosphere, and the core of the star (with a mass now less than the Chandresekhar (sp?) limit of 1.4 solar masses) is on its way to degeneracy and whitedwarfdom.

      The core should mostly be carbon and helium now - with helium and mostly hydrogen being released in the nebula. The Oxygen is probably remnents from so the of various fusion sequences (like the CNO cycle). The hot elemental oxygen is very likely to encounter a couple of Hydrogen atoms, and next thing you know - boom - you've got water.

      As someone else pointed out- the fact that water is such a great absorber of radio energy, and that it only forms early on - it's a great detector.

      Water does exist elsewhere in interstellar space, as a cold vapor generally. It probably comes directly from these sorts of events.

      --
      In illa quae ultra sunt
    4. Re:Water molecules? by wyldeling · · Score: 1

      Your talking about the bulk properties of water. As the other respondents have pointed out, a water molecule is a water molecule regardless of the bulk state the water is in. What your missing is that unless the water molecules are close enough together to begin with, they won't be able to form ice. So, there is a chance that there won't be any ice crystals even when it gets cold enough in the region.

  3. Just a little too late by Mt._Honkey · · Score: 0

    I bet that astronomers are kicking themselves for not seeing this thing about 17 years ago, when it got started in this phase. It is really neat though, I had no idea that water was produced like this. Makes some sense, though.

    --

    Don't Bogart the fish sticks
  4. Star Wars Porn by FortKnox · · Score: 1

    I saw this title, and thought it was some freaky star wars porn.....

    --
    Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
    1. Re:Star Wars Porn by Anonymous Coward · · Score: 0

      Gotta love that fanfic! :-)

  5. More info... by bartlett's · · Score: 3, Informative

    This was observed using the National Radio Astronomy Observatory's Very Large Array, which is a (rather cool looking) group of 27 radio antennas in New Mexico. The NRAO press release on K3-35 contains somewhat more detailed information than the CNN article.

  6. Spelling nazi :-) by WorldSpawn · · Score: 1

    Subrahmanyan Chandrasekhar - Though I have no clue as to how one pronounces that in his native tongue (Hindi?)

    Rather interesting fellow to read about actually..

    1. Re:Spelling nazi :-) by CheshireCatCO · · Score: 2

      Everyone called him "Chandra" which is much easier to work out (soft "ch", the rest is self-explanitory). And hence the name of the X-ray observatory, of course.