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Black Hole Found Inside Globular Cluster

acidrain writes "Contrary to the prediction of some computer models, scientists have found a black hole resting peacefully in a dense nest of stars called a globular cluster. Previously discovered black holes are either similar in size to a large star, or super massive holes which are millions of times bigger than a star is able to remain stable. This finding indicates there may be an intermediate size range of holes residing within these star clusters."

53 of 73 comments (clear)

  1. Yet Another Black Hole by camperdave · · Score: 1, Insightful

    How many black hole discoveries do we need to announce before they no longer become news? Are the previous announcements falling into the gravity well of a collapsed star or something?

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    1. Re:Yet Another Black Hole by __aaclcg7560 · · Score: 2, Funny

      Black holes will never go out of style until a space dog eats a fleet of space ships. That will be news for the next century.

    2. Re:Yet Another Black Hole by Guppy06 · · Score: 3, Funny

      "How many black hole discoveries do we need to announce before they no longer become news?"

      Black Hole Found Inside New Jersey.

    3. Re:Yet Another Black Hole by LouisZepher · · Score: 2, Funny

      To hell with the space dog, I'm more concerned with the mutant space goat.

    4. Re:Yet Another Black Hole by PsyQo · · Score: 2, Funny

      I discovered one between the buttcheeks of some guy called Goatse, but that doesn't make slashdot, now does it?

    5. Re:Yet Another Black Hole by cciRRus · · Score: 4, Funny

      Actually there is just one; the rest were dupes. =)

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    6. Re:Yet Another Black Hole by camperdave · · Score: 1

      Ah... from some sort of gravity lensing effect, no doubt?

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    7. Re:Yet Another Black Hole by UncleTogie · · Score: 1

      Seem to be having trouble with your lifestyle? ;)

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    8. Re:Yet Another Black Hole by peeg · · Score: 1

      Exactly, they will never go out of style because we hardly know anything about them. Black Holes are amazing.

    9. Re:Yet Another Black Hole by Dabido · · Score: 1

      I'm more worried about the coming of the great white hanky.

      --
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    10. Re:Yet Another Black Hole by stigmato · · Score: 1

      Bruce Springsteen was determined to be the event horizon and it has been theorized that his singing is actually spewing forth from the black hole as gamma radiation.

  2. large black holes? by butterberg · · Score: 1

    Previously discovered black holes are either similar in size to a large star, or super massive holes which are millions of times bigger than a star is able to remain stable. Er, what is measured here, when they say: "as large as a star" or even larger? I thought, black holes were singularities without any spacial extension?
    1. Re:large black holes? by odasnac · · Score: 2, Informative

      IANAAP, but i think it refers to the size of its event horizon; it could refer to its mass, but from what i understand mass and event horizon size are pretty well directionally proportional.

    2. Re:large black holes? by DragonWriter · · Score: 1
      Er, what is measured here, when they say: "as large as a star" or even larger?


      I read it as mass, though I suppose it might be volume within or diameter of the event horizon. Or something else. "Size" isn't really clear here.
  3. Rest Easily Oxymoron... by __aaclcg7560 · · Score: 1

    I didn't think black holes rest easily when material crosses the event horizon to be shredded violently into atomic pieces. If there was a black hole in the neighborhood, I don't think anyone would rest easily.

  4. holes of the "a" type by macadamia_harold · · Score: 1

    This finding indicates there may be an intermediate size range of holes

    Much like the modern workplace.

  5. Large by mass by MillionthMonkey · · Score: 4, Informative

    The singularity is a point but the Schwarzchild radius around it is directly proportional to mass. One earth mass is equivalent to something like a few cm of Schwarzchild radius.

    Inside the Schwarzchild radius everything falls into the hole regardless of velocity, no exceptions.

    1. Re:Large by mass by jozeph78 · · Score: 1
      The singularity is a point but the Schwarzchild radius around it is directly proportional to mass. One earth mass is equivalent to something like a few cm of Schwarzchild radius.

      Inside the Schwarzchild radius everything falls into the hole regardless of velocity, no exceptions.


      aka, its event horizon
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    2. Re:Large by mass by j.a.mcguire · · Score: 1

      So where is the schwarzchild radius emitted from? and why aren't we all falling into 3cm holes of doom?

    3. Re:Large by mass by Ambitwistor · · Score: 2, Informative

      The Schwarzschild radius isn't "emitted" from anything. It is simply a location in space, or rather a distance that defines a location. You can define a Schwarzschild radius for any object, even yourself. A black hole (roughly speaking) is a body whose matter has all collapsed into a region smaller than its own Schwarzschild radius. The Earth is not a black hole, because its matter is not contained within a region a centimeter across. Anyway, at a distance of 1 (current) Earth radius, a cm-sized black hole's gravity would not be any stronger than the current Earth's gravity; black holes don't suck things in more strongly than the objects they formed from. (Of course, the reason we are not falling into the center of the Earth is because we are standing on a solid surface; that would not be true for a black hole.)

  6. warning required? by PTBarnum · · Score: 4, Funny

    The important question is, does this black hole have a warning label?

    WARNING: do not drop spaceship keys into black hole

    1. Re:warning required? by AaronHorrocks · · Score: 1

      That would only be the case if the state of California started to legislate stellar objects.

  7. I wonder if time is dilated there... by Progman3K · · Score: 5, Interesting

    If you lived on a planet of the star closest to the black hole, would the passing of your time be measurably different from ours?

    --
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    1. Re:I wonder if time is dilated there... by Rhabarber · · Score: 1

      Wouldn't that at least depend on the velocity sucking my solar system into the hole (in relation to that of the observer - you get it) ?

    2. Re:I wonder if time is dilated there... by Progman3K · · Score: 1

      The article says the black holes are "resting" inside the globular cluster, so that is my question; is/are there possibly (a) solar system(s) near the black hole that are stable?

      For that matter, if they are being pulled into the black hole, how long can a solar system keep its planet(s) orbiting in such a situation? How long could life continue in such a place?

      I'm not a physicist, but I'm sure time passes relatiely (to us) slower in such a place.

      --
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    3. Re:I wonder if time is dilated there... by camperdave · · Score: 1

      Just because there is a black hole in the cluster, doesn't mean that the stars are going to fall in. They could be in a stable orbit around the black hole.

      --
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    4. Re:I wonder if time is dilated there... by shma · · Score: 5, Informative

      According to General Relativity, the passage of time at a location depends on the gravitational field there. So, for instance, if the sun were to collapse into a black hole, there would be no change in the passage of time here. You would have to pass within a few Schwarzschild radii to see an effect (The Schwarzschild radius for the sun is about 3 kilometers, while Earth is 150 million km from the sum)

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    5. Re:I wonder if time is dilated there... by Bemopolis · · Score: 1

      The short answer is no — if your sun were close enough to the black hole to have a significant time dilation, the tidal forces on your sun (and planet) would rip it apart.

      But at least we would get to see it in slow motion.

      --
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    6. Re:I wonder if time is dilated there... by MillionthMonkey · · Score: 3, Informative

      If you lived on a planet of the star closest to the black hole, would the passing of your time be measurably different from ours?

      Measurably but imperceptibly different from ours. But for the planet, no different than before. The gravity along a planet's orbit would be unchanged by the star's collapse. If it survives the red giant phase or the explosion, a planet's orbit won't be expected to change. By me, anyway.

      The interesting spacetime effects that we associate with black holes take plase close to the singularity at the center, in regions of space that were formerly buried under the original star's surface. It would be hard to explain how you could find a planet bound in a stable orbit in there now. In the absence of gravity from a third body, things will either strike the singularity or take a mostly hyperbolic trajectory past it.

      And be careful what you mean when you say "would the passing of your time be measurably different from ours" because some people take that to mean that you'll look down at your watch and see the hands moving faster or slower than usual. You'll always experience proper time for your reference frame, which basically means you'll never see that. The difference is with clocks far away from the black hole, which tick more quickly than clocks closer to it.

    7. Re:I wonder if time is dilated there... by Progman3K · · Score: 1

      Thanks, that's a really clear answer.

      When I wrote "would the passing of your time be measurably different from ours" I meant for an observer comparing both places. I should have been more precise.

      I guess the real answer (which you pointed out) is that you would have to be within the space the star itself used to occupy for relativistic effects to manifest (for an observer, again). And even then, your answer seems to say that at that point, there is no more comparison possible because no information could exit... Cool. Did I get that right?

      --
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    8. Re:I wonder if time is dilated there... by rufty_tufty · · Score: 4, Funny

      "The article says the black holes are "resting" inside the globular cluster"

      Next you'll be telling me its pining for the fyords!

      --
      "The weirdest thing about a mind, is that every answer that you find, is the basis of a brand new cliche" -
    9. Re:I wonder if time is dilated there... by niktemadur · · Score: 1

      They could be in a stable orbit around the black hole.

      Considering that the density of stars in a globular cluster and the galactic center would be quite similar, I would imagine that in time-lapse it would look something like this:
      http://video.google.com/videoplay?docid=4684576261 095940634&q=%22galactic+center%22&hl=en

      The article says that contrary to the prediction of some computer models.... There it is, some computer models. Obviously, not everything was factored in these simulations. Also, the article says that the black hole detected is calculated to contain 400 solar masses.
      Elsewhere in this thread someone mentioned that since a black hole was detected in the second cluster they looked at, it's a fifty-fifty proposition as of now. I would imagine that it's closer to a hundred percent probability, they need to look again in the first cluster with more sensitive instruments or more closely - why would the same mechanism generate different results (black hole/no black hole) in different clusters? The improbable alternative is that different mechanisms generate the same result. I just don't see it.

      --
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    10. Re:I wonder if time is dilated there... by niktemadur · · Score: 1

      Oops, sorry about the italics, I messed up the html code. Here it goes again:

      The article says that contrary to the prediction of some computer models.... There it is, some computer models. Obviously, not everything was factored in these simulations. Also, the article says that the black hole detected is calculated to contain 400 solar masses.
      Elsewhere in this thread someone mentioned that since a black hole was detected in the second cluster they looked at, it's a fifty-fifty proposition as of now. I would imagine that it's closer to a hundred percent probability, they need to look again in the first cluster with more sensitive instruments or more closely - why would the same mechanism generate different results (black hole/no black hole) in different clusters? The improbable alternative is that different mechanisms generate the same result. I just don't see it.

      --
      Lil' Thindime, lilting a lacrimose lament, krashes the kwaint konfines of Kokonino Kounty
    11. Re:I wonder if time is dilated there... by Kagura · · Score: 1

      You would have to pass within the old radius of the sun to see any new effects.

    12. Re:I wonder if time is dilated there... by Ernesto+Alvarez · · Score: 1

      Close. IANAP, but let me try.

      Those relativistic effects you're talking about would manifest if the object is massive enough, and the orbiting object is close enough. Something like that happens to mercury, but the effect is not that big.

      So, for these effects to manifest, it is not necessary for the orbiter to be inside within the space used to be occupied by the star. If a star collapses and the orbiting planet remains in the same orbit, the relativistic effects will be the same as they were (under the same assumptions as GP post).

      Now, if you allow the planet to move towards the newly formed black hole, the relativistic effects will increased. So, the closer you are, the bigger the dilation (always from a distant observer). So, it is not necessary to be where the star used to be, but it sure helps.

      About what you added (".. there is no more comparison possible because no information could exit.."), there is one point you cross as you aproach the black hole. It's called the event horizon, that is a point of no return, once you cross it, you'll hit the singularity (the center of the black hole). Once the orbiter crosses the horizon, you'll never know anything about it anymore, and it'll eventually be destroyed. That's what you were talking about.

      The event horizon is definitely going to be inside the radius of the former star, but there should be some space between the event horizon and the radius of the former star.

      The GP poster was talking about an object close to the black hole but outside the event horizon. Your guess was inside the event horizon.

    13. Re:I wonder if time is dilated there... by Kuciwalker · · Score: 1

      No different than before, because the gravitational field of a sphere outside of that sphere is equal to the graviational field of all the mass concentrated at a point. So the graviational effect of the star/black hole on the planet would be unchanged.

    14. Re:I wonder if time is dilated there... by StikyPad · · Score: 1

      Not measurably, no.. at least, not until we send something there to measure it with.

    15. Re:I wonder if time is dilated there... by Presidential · · Score: 1
      Not measurably, no.. at least, not until we send something there to measure it with.


      Wouldn't the measurement results be skewed by the act of measuring?
      --
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  8. Well, sure by Phanatic1a · · Score: 1

    "People have seen stellar-sized black holes that form from [an exploded] star, and then there are the super-massive black holes at the centres of galaxies that are millions of times the mass of our Sun - but there's nothing in between.

    That's what we've seen because that's where we've gone looking. You'd expect holes to form from supernovas, so you look at the center of planetary nebulae, where stars used to live before they exploded. You'd expect them to form at galactic centers, so you look there to find them. There's nothing in between because we haven't gone looking for the in-betweens yet.

  9. Black hole do not change their mass by aepervius · · Score: 2, Informative

    As far as I remmember, black hole have the same mass as the collapsing star (before starting slowly to dissipate). Thus the same gravity as the as the star would be felt at the same distance. There is albeit a difference, within the schwarschild radius, the gravity pull is enough to pull everything without possible escape even light. Normally this radius smaller than the radius of the star itself before collapsing, if the mass would be at a point. In other word if the sun was to suddenly transform in black hole, the earth would happily go wander on the same orbit.

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    1. Re:Black hole do not change their mass by SuiteSisterMary · · Score: 5, Interesting

      (note: this is from memory)

      Our sun is defined as 'one solar mass.'

      Very basically, a star's tendancy to collapse in on itself is countered by the fact that it's a big old nuclear fireball. As it runs out of hydrogen to burn, it starts to collapse in on itself again, until it starts burning helium. Once the helium is gone, it starts to collapse again.

      Any given star of less than 1.4 solar masses will stop collapsing and turn into a white dwarf, due to the fact that it's gravity isn't enough to overcome the repulsion of electrons. (If this white dwarf gets some new material, say, by having a red giant close enough that it can gather material from it, it will explode, giving us a supernova.)

      Any given star of greater than 1.4 solar masses but less than 3 solar masses will overcome this, but get halted by inability to squish neutrons together.

      Anything bigger than 3 solar masses will overcome neutron degeneracy, and collapse even further into a black hole.

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    2. Re:Black hole do not change their mass by sco08y · · Score: 1

      Due to Hawking radiation black holes *do* eventually lose mass and "evaporate." This happens quite quickly for small black holes and it's plausible that we could witness a nearby black hole evaporate.

  10. Thanks, scientists! by Junior+J.+Junior+III · · Score: 1

    So THAT'S where I left that thing, I'd been looking all over for it!

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  11. of course it's possible by ILuvRamen · · Score: 1

    if it's in a cluster of stars that's really old, it's probably had time to suck up several and normally I don't think we'd be able to tell if say it ate five stars and got 5x bigger (well the event horizon goes out further, it doesn't actually get bigger) but if I remember correctly, gravity increases exponentially when mass is added, which is why the moon at 1/3 the size has 1/6 the gravity as earth so if it sucked up 5 stars, it would look like a couple hundred times larger and be quite noticeable.

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    1. Re:of course it's possible by ILuvRamen · · Score: 1

      not if it's moving (e=mc2) lol
      but I think you calculated that way wrong. If it has 27% the radius, it can't be 2% the volume without practically being a nuetron star. The moon's mass is (in kg with 24 0's stripped off) is 0.073 and the earth's mass is 5.97 on the same scale. But the gravity in meteres per second squared (for some reason) is 1.6 for the moon and 9.8 for the Earth and if you divide those out, you'll see that they're not linear. Also, density affects gravity in a given area greatly too.

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  12. Question: Why stars don't fall into the center? by vbwyrde · · Score: 2, Informative

    "Globular clusters, which are found in the halo of a galaxy, contain considerably more stars and are much older than the less dense galactic, or open clusters, which are found in the disk." - http://en.wikipedia.org/wiki/Globular_cluster What this makes me wonder is how the Globular Cluster, being much older than other galactic structures neither spins, nor contracts into itself. I would think that a Black Hole at the center would gobble the stars closest to it, increasing its gravitational attraction so that all of the surrounding stars would free fall straight "down" into it. The spin of other galaxies makes it so that stars do not just fall straight down into their own central black holes, but instead fall in a spiral toward it so that it takes a very long time for them to fall into it. But the Globular Cluster, with stars just hanging there in a spherical shape around it... I must ask - how come the stars have not fallen into the center long, long ago? Anyone have a theory on that?

  13. Heisenberg's Principle by alienmole · · Score: 1

    If you don't look for something in a particular place, you won't find it there. This is so obvious that Heisenberg called it his Duh! Principle (little-known fact). The corollary of this principle is you won't know if something is in a particular place until you look for it there. This led Heisenberg to develop his Uncertainty Principle, and social studies has never been the same since.

  14. I need some time off by paniq · · Score: 1

    I just read "Schwarzchild anus" :(

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    1. Re:I need some time off by MillionthMonkey · · Score: 1

      Well, I missed the second "s" in "Schwarzschild" as usual which probably didn't help.

  15. Re: Ah, not quite. by Black+Parrot · · Score: 1

    > According to Electric Universe theory, which explains the cosmos much better than nuclear physics, relativity, and quantum physics

    That's wishful thinking. Everyone knows that Time Cube Theory is the correct one.

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  16. More info by scdeimos · · Score: 1

    The following article has a little more info than the original (and a dodgy artist's impression of a stellar-mass black hole):

    Black hole boldly goes where no black hole has gone before

  17. Thanks . . . by KenSeymour · · Score: 1

    for that link. It led me eventually to a wonderful web site.

    That site, in turn, got me to Are You a Quack?.

    Years ago, my being a Physics major qualified me as a crank magnet. I guess the Physics professors were too busy so I was dealing with the overflow.

    --
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  18. Re:Everything falls into the hole? Really? by bhiestand · · Score: 1

    Inside the Schwarzchild radius everything falls into the hole regardless of velocity, no exceptions.
     
    And we know this how? While it would probably be better to say "no known exceptions", we do have a fairly good set of data on this. The evidence is pretty strong, from what's been observed, that radiation, light, matter, and the entire electromagnetic spectrum is unable to escape, regardless of velocity. Keep in mind that a Black Hole, by definition, cannot be escaped by anything. This is according to the theories which initially predicted and defined black holes, based upon general relativity. Indeed, if anything escapes from within the Schwarzschild Radius, the object in question is not, by definition, a black hole.

    IANAQP, of course, but it appears debatable whether Hawking Radiation escapes or not. I've read little on the subject, but it seems that Hawking Radiation, if it indeed exists and the theories are correct, originates from just beyond the event horizon anyways.
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