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Fast-Moving Black Hole

Posted by michael on from the vacuum-cleaner dept.

otisaardvark writes "New Scientist story about a very fast moving Black Hole in our very own Galaxy. Seems it was formed from a supernova explosion. I wish stars like this could have a more exciting name than GRO J1655-40 though. More at the BBC."

12 of 49 comments (clear)

  1. Here is more cool black hole news: by Neil+Blender · · Score: 4, Interesting

    Merging Black Holes

  2. Re:I wonder... by GigsVT · · Score: 5, Funny

    Yep, if we ever got close enough to a black hole, it would be the solution to global warming, corruption in government, freedom on the Internet, minority rights, energy production, and pretty much every other petty human problem you can think of.

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  3. Re:I wonder... by Santos+L.+Halper · · Score: 3, Interesting

    I've read that if you could get close enough to a black hole, and you threw something into it that was attached to a cord strong enough, the black hole will pull the matter into in, thereby pulling the cord, which in turn can be hooked to a turbine to produce electricity. The book (The Last Three Minutes) says that theoretically, you could get energy consistant with e=mc^2 this way.

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    "Ask not for whom the bone bones. It bones for thee." --Bender
  4. THis is no time to joke. by Unknown+Poltroon · · Score: 4, Funny

    Your levity cant stand up under the gravity of the situation.

    yeah yeah, -1, bad puns.

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  5. Time Travel by Merlin42 · · Score: 3, Interesting

    Im not so sure that this is really practical in the sense you meant, but just being near a large enough blackhole would provide a simple one way time machine (cf twins paradox).

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  6. Re:I wonder... by NineBall · · Score: 4, Informative

    Black holes the size of protons would evapourate in seconds, due to the hawking radiation, and somehow I don't think you want to get too close to a large one. I'd love to see someone try, though, that would be a great stunt to see on Jackass.

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  7. Re:What should I believe? by NineBall · · Score: 3, Insightful

    Remember, in science, no theory is ever actually correct, merely proven to be beyond reasonable doubt.

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  8. Re:I wonder... by dunedan · · Score: 3, Funny

    except of course that ever present once we get inside cuasality could be violated and then your food keeps getting warmer and uncooking itself if you don't hurry up and eat it

    What a pain :)

  9. This doesn't make sense to me. by Peter+T+Ermit · · Score: 4, Insightful
    Can anyone help me understand? Two problems:

    1) The black hole has a companion star, so wouldn't a kick of that magnitude tear it away from its companion and preclude it from acquiring another until it slows?

    2) Even ignoring the mass of the companion, the estimates are that the BH is about 7 solar masses. That means that the BH has acquired a kinetic energy of 1/2 * 7 * (2^30 kg) * (10^5 m/s)^2 = about 10^41 J of energy, which is about 1/1000 of the energy of the SN explosion (10^51 erg = 10^44 J). To me, that seems like an exceedingly large fraction of a roughly isotropic explosion converted into motion. It gets even worse if you throw in the mass of the companion.

    Anyone have any insights into how this can happen?

    1. Re:This doesn't make sense to me. by Peter+T+Ermit · · Score: 4, Insightful
      10^54 ergs would resolve a lot of the difficulty, but I thought that SNs couldn't produce anything much more than 10^51 or so ergs; anything significantly greater than that is a "hypernova" and is thought to have a different origin. (Or that the SN is beamed, which gives the illusion of higher energies.)

      Even so, I'm still confused about the companion, as the system's binding energy is probably rather less than its kinetic energy.

    2. Re:This doesn't make sense to me. by stonewolf · · Score: 3, Interesting

      Nice to see that this bothers people who have detailed understanding of the physics.

      Seems there are several problems unresolved questions here.

      Is the black hole moving with a campanion star? Or, just skimming off some mass as it passes by? If it is actually moving *with* the companion star, what kept them together? Assuming a SN explosion accelerated the black hole to 400,00 kph, how did it drag along another star? Even if they were a close binary pair before the SN explosion, wouldn't the black hole now have system escape velocity?

      Another question, how off balance does the explosion have to be to generate this kind of speed? If the explosion is 1% of balance, how much mass energy was released in the total explosion to get this speed? How do you get a SN explosion that is that off balance?

      Could this pair have been accelerated by another mechanism such as a close pass to a tight binary star system? How tight would it have to be? What kind of stars (neutron, black holes...) to get a pair with enough energy to speed something up like that?

      Like you said. this doesn't make sense.

      Stonewolf

  10. Re:I wonder... by Anonymous Coward · · Score: 4, Funny

    I think a black hole ate the periods in your sentences.