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posted by martyb on Saturday May 18 2019, @02:47AM   Printer-friendly
from the a-proton-and-a-neutron-walk-into-a-black-hole dept.

In a presentation given on April 15th at the American Physical Society in Denver, Researcher Ana Bonaca of the Harvard-Smithsonian Center for Astrophysics presented evidence for a "dark impactor" tearing through our galaxy's longest stellar stream - GD-1.

Stellar streams are lines of stars moving together across galaxies, often originating in smaller blobs of stars that collided with the galaxy in question. The stars in GD-1, remnants of a "globular cluster" that plunged into the Milky Way a long time ago, are stretched out in a long line across our sky.

Under normal conditions, the stream should be more or less a single line, stretched out by our galaxy's gravity, she said in her presentation. Astronomers would expect a single gap in the stream, at the point where the original globular cluster was before its stars drifted away in two directions. But Bonaca showed that GD-1 has a second gap. And that gap has a ragged edge — a region Bonaca called GD-1's "spur" — as if something huge plunged through the stream not long ago, dragging stars in its wake with its enormous gravity. GD-1, it seems, was hit with that unseen bullet

The impactor doesn't match the path of any luminous object according to Bonica. Additionally it is far more massive than a star, approximately a million times more massive than the sun, and between 10 and 20 parsecs across.

That leaves limited possibilities - possibly a black hole, but this would be a black hole on-par with the supermassive black holes found at the center of galaxies. Additionally

we'd expect to see some sign of it, like flares or radiation from its accretion disk. And most large galaxies seem to have just a single supermassive black hole at their center.

This leaves an intriguing possibility. A dark matter object or structure.

With no giant, bright objects visible zipping away from GD-1, and no evidence for a hidden, second supermassive black hole in our galaxy, the only obvious option left is a big clump of dark matter. That doesn't mean the object is definitely, 100%, absolutely made of dark matter, Bonaca said.

The findings are based on data obtained from the ESA Gaia mission.

Bonica's results were well received but have not yet been published in a peer reviewed journal.


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  • (Score: 2) by Runaway1956 on Saturday May 18 2019, @02:54AM (5 children)

    by Runaway1956 (2926) Subscriber Badge on Saturday May 18 2019, @02:54AM (#844910) Journal

    Ali? Tyson? ??? Come on, give us a name!

    • (Score: 1, Offtopic) by takyon on Saturday May 18 2019, @02:56AM (2 children)

      by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Saturday May 18 2019, @02:56AM (#844911) Journal

      deGrasse Tyson #MeToo.

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      • (Score: 1, Offtopic) by Gaaark on Saturday May 18 2019, @03:39AM

        by Gaaark (41) on Saturday May 18 2019, @03:39AM (#844927) Journal

        OH, NO YOU DI'NT!
        YOU di'nt jus' go dere, don't you!

        Oh, oh....I'm coming, Elizabeth!

        --
        --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
      • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @08:35AM

        by Anonymous Coward on Saturday May 18 2019, @08:35AM (#844970)

        When Runaway refers to "Tyson", he means "chicken". It's an Arkansas thang.

    • (Score: 1) by Chocolate on Saturday May 18 2019, @03:53PM (1 child)

      by Chocolate (8044) on Saturday May 18 2019, @03:53PM (#845031) Journal

      Are we naming space events like we name hurricanes now?

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      Bit-choco-coin anyone?
      • (Score: 2) by Runaway1956 on Saturday May 18 2019, @04:01PM

        by Runaway1956 (2926) Subscriber Badge on Saturday May 18 2019, @04:01PM (#845036) Journal

        Only the big ones, apparently. No one has launched the "Name a space event after your retarded children" non-profit yet.

  • (Score: 2) by The Mighty Buzzard on Saturday May 18 2019, @03:11AM (22 children)

    If you see shit you can't explain or your math don't add up, just blame it on dark matter? That is not how you fucking science in general and not how you physics very specifically.

    --
    My rights don't end where your fear begins.
    • (Score: 2, Funny) by Gaaark on Saturday May 18 2019, @03:42AM (4 children)

      by Gaaark (41) on Saturday May 18 2019, @03:42AM (#844928) Journal

      Das da NEW physicks!

      Blame darky!

      Yeah...if I had to sit in a room full of people masturbating over dark matter, I'd fecking scream.

      --
      --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
      • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @04:20AM

        by Anonymous Coward on Saturday May 18 2019, @04:20AM (#844930)

        No kidding, I beat it to visible matter only!

      • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @04:35AM

        by Anonymous Coward on Saturday May 18 2019, @04:35AM (#844932)

        BBC?

        Dark matter matters.

      • (Score: 1) by RandomFactor on Saturday May 18 2019, @01:54PM (1 child)

        by RandomFactor (3682) Subscriber Badge on Saturday May 18 2019, @01:54PM (#845008) Journal

        Dancing in the Gaaarrk?

        In the dark matter, no one can hear you scream?

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        • (Score: 2) by Gaaark on Saturday May 18 2019, @08:28PM

          by Gaaark (41) on Saturday May 18 2019, @08:28PM (#845124) Journal

          That's my Indian name: Dances with Gaaarks Wife.

          --
          --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
    • (Score: 1, Interesting) by Anonymous Coward on Saturday May 18 2019, @04:25AM (15 children)

      by Anonymous Coward on Saturday May 18 2019, @04:25AM (#844931)

      Buzzy buzzy buzzy. Give us your genius theory or gtfo. They discuss the various alternatives and explain why they go with dark matter. I'm not a big fan of dark matter myself, but their reasoning is fine.

      • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @05:30AM (9 children)

        by Anonymous Coward on Saturday May 18 2019, @05:30AM (#844941)

        If it leads to "dark matter" (invisible shit used to explain why the theory predicts the wrong thing) then the reasoning is not fine by definition. There is no advantage of dark matter over "god did a miracle". It can "explain" any and all deviations from what was expected.

        • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @07:33AM (7 children)

          by Anonymous Coward on Saturday May 18 2019, @07:33AM (#844961)

          As I said I'm not a fan of dark matter, but if you're only other hypothesis is a god-miracle then I'll stick with the article's authors on this one.

          • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @01:37PM (3 children)

            by Anonymous Coward on Saturday May 18 2019, @01:37PM (#845005)

            Not sure why you would say that, seems you failed to understand that post.

            • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @03:32PM (2 children)

              by Anonymous Coward on Saturday May 18 2019, @03:32PM (#845025)

              It is possible to think a theory isn't very good while admitting there aren't any good alternatives we know if yet. Dsrk matter may be total bunk, but these hiles in the galaxy could be explained by some rogue dark matter. If your only rationale is "I don't like dark matter" then prepare for people to give your opinion little serious thought.

              I don't have a better theory to explain this and I refuse to rule out dark matter just because I think it is a flawed concept. That is part of maintaining an open mind instead of falling back on dogma.

              • (Score: 1, Insightful) by Anonymous Coward on Saturday May 18 2019, @04:14PM (1 child)

                by Anonymous Coward on Saturday May 18 2019, @04:14PM (#845047)

                Where do you get that my "only rationale is 'I don't like dark matter'"? It is a bad "theory" because it is no better than god of the gaps or magic. It is so vague that it explains anything.

                If there was any practical use for any of this stuff people would be using MOND and friends since it works. There is no way to use "dark matter" because no one knows how much should be there until after the measurements are made and compared to the wrong predictions of GR.

                It is such an obvious degenerating research programme (Lakatos), the only people who could still believe in this theory have to be ignorant of history and philosophy of science.

                • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @06:02PM

                  by Anonymous Coward on Saturday May 18 2019, @06:02PM (#845091)

                  As I said.....

                  My personal theory is that circular arguments create temporal anomalies that for some strange quirk of quantum chronodynamics aggregate in specific non-local areas creating a spacetime disturbance that destroys the very fabric of our physical universe. These psycho-spatial phenomena must be corrected in the higher order dimensions more actively governed by consciousness and thus was born the human conception of heaven and hell. It is actually just an interdimensional spreadsheet misinterpreted by some ignorant goat herders that found a psychoactive weed in the mountains and got a glimpse of what others consider a very boring maintenance chore.

          • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @03:45PM (2 children)

            by Anonymous Coward on Saturday May 18 2019, @03:45PM (#845027)

            Magic. To be specific, dark magic. The kind where you spend your soul, or "life force", to make things happen. Sell your soul to Satan, and anything is possible. That's why it's "dark matter" and not "light matter". Come over to the dark side.

            • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @04:18PM

              by Anonymous Coward on Saturday May 18 2019, @04:18PM (#845050)

              Dark matter could actually be made of light. They need to add up the mass of all the photons in each galaxy.

            • (Score: 2) by The Mighty Buzzard on Saturday May 18 2019, @07:05PM

              You forgot to mention the cookies.

              --
              My rights don't end where your fear begins.
        • (Score: 1) by RandomFactor on Saturday May 18 2019, @01:55PM

          by RandomFactor (3682) Subscriber Badge on Saturday May 18 2019, @01:55PM (#845009) Journal

          Waaaait.....genius! God=Dark Matter

          --
          В «Правде» нет известий, в «Известиях» нет правды
      • (Score: 2) by The Mighty Buzzard on Saturday May 18 2019, @07:06PM (4 children)

        That's not how science works. You don't go with a colossally shitty theory until you come up with a better one, you say "fuck if we know" until you can prove it one way or the other.

        --
        My rights don't end where your fear begins.
        • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @09:34PM (3 children)

          by Anonymous Coward on Saturday May 18 2019, @09:34PM (#845134)

          No one has stated that dark matter is the answer, just the best theory so far. Possibly a black hole, but as stated those usually leave some observable evidence. Since they did not state that it is definitively dark matter then this is exactly how science works. You make the best guesses possible and go from there.

          Maybe schooling woulda been a good move for you, you really give yourself way too much credit.

          • (Score: 2) by The Mighty Buzzard on Sunday May 19 2019, @09:59AM (2 children)

            This would be a valid assertion if the dark matter hypothesis held any kind of water to begin with. Currently it does not though. At this point it's no more deserving of inclusion in the list than a Magic Fairy Dust hypothesis. "Huh, our math's coming out horribly and unpredictably wrong on galactic and larger scales," does not mean you go adding Magic Fairy Dust until it comes out right then claim the existence of Magic Fairy Dust is decent working theory because adding enough to unfuck your math unfucked your math.

            --
            My rights don't end where your fear begins.
            • (Score: 0) by Anonymous Coward on Sunday May 19 2019, @03:38PM (1 child)

              by Anonymous Coward on Sunday May 19 2019, @03:38PM (#845252)

              You should ask the nearest grandma to bake you some humble pie. Magical fairy dust is worth a lot more than your useless complaining.

              I think DM is wrong and our theory is just incomplete, but unlike you I don't toss out possibilities because of a massively over inflated ego. You are a pox on rational discussion.

              • (Score: 2) by The Mighty Buzzard on Sunday May 19 2019, @10:56PM

                Show me the tested predictions the DM hypothesis has made possible -- without having to massage the math to fit -- or it is Magical Fairy Dust. It may or may not be true Magical Fairy Dust but it's utterly and completely unproven in any way at this point. It is a Wild-Assed Guess.

                --
                My rights don't end where your fear begins.
    • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @08:00AM

      by Anonymous Coward on Saturday May 18 2019, @08:00AM (#844968)

      It was caused by ancient aliens!

  • (Score: 2) by Phoenix666 on Saturday May 18 2019, @11:34AM (1 child)

    by Phoenix666 (552) on Saturday May 18 2019, @11:34AM (#844986) Journal

    now i know what to call it the morning after eating squid ink paella.

    --
    Washington DC delenda est.
    • (Score: 0) by Anonymous Coward on Saturday May 18 2019, @03:55PM

      by Anonymous Coward on Saturday May 18 2019, @03:55PM (#845033)

      Add some chill's into teh mix to make it a Ring of Fire Dark Impacta!

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