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Space Science

Astronomers Find the Biggest Black Hole Ever Measured (astronomy.com) 110

"Astronomers have found the biggest black hole ever measured -- it's 40 billion times the sun's mass, or roughly two-thirds the mass of all stars in the Milky Way," writes Astronomy.com.

A reader shares their report: The gargantuan black hole lurks in a galaxy that's supermassive itself and probably formed from the collisions of at least eight smaller galaxies.

Holm 15A is a huge elliptical galaxy at the center of a cluster of galaxies called Abell 85... When two spiral galaxies -- like our Milky Way and the nearby Andromeda Galaxy -- collide, they can merge and form an elliptical galaxy. In crowded environments like galaxy clusters, these elliptical galaxies can collide and merge again to form an even larger elliptical galaxy. Their central black holes combine as well and make larger black holes, which can kick huge swaths of nearby stars out to the edges of the newly formed galaxy. The resulting extra-large elliptical galaxy usually doesn't have much gas from which to form new stars, so its center looks pretty bare after its black hole kicks out nearby stars. Astronomers call these huge elliptical galaxies with faint centers "cored galaxies." Massive cored galaxies often sit in the centers of galaxy clusters.

The authors of the new study found that Holm 15A, the enormous galaxy at the center of its home galaxy cluster, must have formed from yet another merger of two already-huge cored elliptical galaxies. That would mean Holm 15A probably formed from the combination of eight smaller spiral galaxies over billions of years... This series of mergers also created the black hole in its center, a monster about as big as our solar system but with the mass of 40 billion suns.

One of the study's authors says their discovery finally confirms the current theory about how quasars work.
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Astronomers Find the Biggest Black Hole Ever Measured

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    • She's taken 7 hits to the starboard bow, Captain, and she hasn't even shuddered.

  • by Anonymous Coward on Sunday December 08, 2019 @06:50PM (#59499010)

    I thought black holes were zero-dimensional.

    • by Livius ( 318358 ) on Sunday December 08, 2019 @07:00PM (#59499040)

      They mean the volume bounded by a black hole's event horizon, which is a definite volume that can be calculated.

      Whether whatever is inside occupies a particular volume, or if that question even makes sense, is not known.

      • Well actually the formalism of general relativity does not care if something is inside or outside of the event boundary. It's just that on the outside at least you can detect somethings

    • I don't know why a thoughtful question like this is modded to zero, but the answer is probably to clear up a confusion between mass and density.

      While the dimensions are zero, the mass is not. That's why most (if not all) black holes spin and have a magnetic field resulting in a charge greater than zero.

      • Reality did not read your paper.

        And if it did, it would point out, that whenever you hit an infinity or a zero, that is an indicator that your theory is wrong or applied outside its legitimate boundaries.

        We currently have nothing that can fully explain black holes. And we won't, until we at least properly merged the the standard model of quantum physice with relativity.

        • If 'explain' means providing extra information about what black holes do, then what difference would quantum mechanics make? Would it result in any type of observation being different? So unifying theories don't count . I also don't count Hawking radiation because that doesn't require a quantum theory of gravity.
          And gravitons , well, I've read you wouldn't be able to observe individual gravitons anyway.

        • And we won't, until we at least properly merged the the standard model of quantum physice [sic] with relativity.

          Reality didn't read your paper, either. There's no theory in the models that suggest this as an impediment.

          When we are ignorant, it's foolish and misleading to make flat statements like that.

        • whenever you hit an infinity or a zero, that is an indicator that your theory is wrong or applied outside its legitimate boundaries.

          On the other hand, if (and that is a big word for such a little word) the discussions of space being quantised and there being a meaningful non-zero minimum size to a distance [wikipedia.org], then both the zero volume and the infinite density cease to be an issue.

          It needs maths way over my head.

          I started getting headaches about this sort of thing by thinking about a black hole evaporating

    • When people talk about the "size" of a black hole, the generally mean the Schwartzchild radius - the radius from which nothing can escape. The black hole's mass can be detected from its gravity and it acts like a point mass containing all of the mass that formed, and fell into the black hole.

      (rapidly rotating black holes are a little more complicated but the basic idea is the same).

    • There is no reason to think this. A large enough black hole may have very modest density internally, with structure. If our universe is "closed", if it forms a black hole with its net mass, then we are all part of the internal structure of a black hole.

      Also, there are potentially such things as "toroidal black holes", or Kerr black holes, black holes spinning with enough mass that they form a donut-like shape. That is not "zero dimensional",

    • I thought black holes were zero-dimensional.

      We have no idea, the only (best) theory of gravity "The General Relativity" breaks down in the regime of black holes and the Big Bang, producing infinities, which is in physics a sign that the theory is not sufficient.

      Talking about the size of black holes usually their mass (hence "... n solar masses") is mentioned, as there are just a few parameters describing them (it's still debatable, but spin, mass and charge is all one can tell about a black hole). Mass directly translates to the so called "event hor

    • but do they have blockchain ? as the guy in the answer says, they probably mean its radius of influence , more or less ..
  • by CaptainDork ( 3678879 ) on Sunday December 08, 2019 @06:52PM (#59499016)

    ... and it brings to mind some odd things about black holes.

    If I was watching a person falling in to one, they would appear to slow down more and more as they approached the event horizon that I would never actually see them cross.

    For the person falling, they'd be like, "Hey, no big deal ... I'm hauling ass toward the center." and things would not end well in very short order.

    • So take your thought problem, but instead of a person falling into a black hole... make it a second black hole which is falling into the first.

      We have observed black holes which we believe have merged from multiple predecessors. We have seen radio evidence of what we believe is the merger of two black holes. So how does that work, exactly, given time dilation?

      • We haven't actually observed any particular body, large or small, falling into a black hole. However, the math shows that time approaches infinity in direct proportion as the gravitational filed becomes more dense.

        We'd have to have eyes on an object and "tag" it. We have a major problem with peering into the nearest black hole (massive one in our galaxy), because of all the dust and larger objects between the Earth and there and NO way (yet) to observe a particular object.

        The closest massive is in the Andr

        • by 93 Escort Wagon ( 326346 ) on Sunday December 08, 2019 @07:57PM (#59499180)

          We haven't actually observed any particular body, large or small, falling into a black hole.

          Actually, on more than one occasion we have now observed perturbed gravity waves ostensibly resulting from the merger of two black holes.

          https://www.ligo.caltech.edu/n... [caltech.edu]
          https://astronomynow.com/2016/... [astronomynow.com]
          https://www.space.com/38288-gr... [space.com]
          https://www.nytimes.com/2017/0... [nytimes.com]

          • ... observed perturbed gravity waves ostensibly ...

            That's what I said, "We haven't actually observed .."

            • by Bengie ( 1121981 )
              Maybe I'm missing something, but he's saying that we did ostensibly observed a blackhole falling into another blackhole. Unless you have a way to prove it wrong, we must assume that's what has happened.
              • Maybe I'm missing something, but he's saying that we did ostensibly observed a blackhole falling into another blackhole. Unless you have a way to prove it wrong, we must assume that's what has happened.

                There's no way to prove an "ostensibly."

                Ostensibly is an adverb you use to talk about something that looks one way, but underneath there's the hint of a different motivation for that action.

                • I see a duck, peacefully wandering around on the surface of a pond.
                  Ostensibly, those feet are going like the clappers under the water, but I can't see it with the sun and sky reflecting on the surface of the water,

                  The burder of proof can't be shifted in either direction - it may be theorised that we think two black holes have merged, but equally we can never confirm it through empirical observation.

                  You could always try using math against itself - because two black holes getting closer and closer won't direc

        • We have a major problem with peering into the nearest black hole (massive one in our galaxy),

          Sgr A* is the nearest object which we are certain exceeds the mass-radius limits so that it has to be a black hole. It is the supermassive black hole very close to the centre of the Milky Way galaxy. It masses a bit over 4 million solar masses. But it is almost certainly not the nearest black hole. Given the frequency of supernovae and hypernovae in the observable universe, it is statistically implausible for there

          • Damn, I got my BLOCKQUOTE tags nested instead of sequential. That should be QUOTE response QUOTE response response2 respose3, paragraphically
      • by joe_frisch ( 1366229 ) on Sunday December 08, 2019 @08:58PM (#59499374)

        Not a simple question. I believe that if you solve for the gravitational field of a black hole when a large object falls in (including another black hole) there are some fluctuations as the object gets close to the event horizon - and that energy is dissipated as gravity waves quite rapidly) . The resulting gravitational field rapidly settles down to look like that of a black hold of the combined mass (minus any emitted gravity waves). (rapidly is milliseconds for stellar mass black holes)

        As viewed from the outside an object falling in takes forever to reach the center - but it becomes invisible (amount of light decreases exponentially near the horizon) so it is effectively invisible.

        Its not clear it makes sense to talk about what happens to the object inside of the black hole because that is in theory not observable.

        Makes my head hurt.

        • Not a simple question. I believe that if you solve for the gravitational field of a black hole when a large object falls in (including another black hole) there are some fluctuations as the object gets close to the event horizon - and that energy is dissipated as gravity waves quite rapidly) . The resulting gravitational field rapidly settles down to look like that of a black hold of the combined mass (minus any emitted gravity waves). (rapidly is milliseconds for stellar mass black holes)

          As viewed from the outside an object falling in takes forever to reach the center - but it becomes invisible (amount of light decreases exponentially near the horizon) so it is effectively invisible.

          Its not clear it makes sense to talk about what happens to the object inside of the black hole because that is in theory not observable.

          Makes my head hurt.

          As a matter (see what I did there) of fact, general relativity equations evaluate to values divided by zero when gravity approaches infinity, resulting in the "infinity problem."

          String "theory" (it's not, it's a hypothesis) was a way of theoretically getting around those infinities, but spawned unwanted anomalies in the form of at least 11 dimensions and multiple universes.

          • String "theory" (it's not, it's a hypothesis) was a way of theoretically getting around those infinities

            So wouldn't that make it "hypothetically getting around those infinities"?

          • String "theory" (it's not, it's a hypothesis)

            It's a set of hypotheses. Someone did an estimate a few years ago and came up with a large number of possible theories (sets of coherent equations) in the set of "string hypotheses" - I forget if the answer was billions of theories, 10^billions of theories, or 10^^^(billions of times)^^^^2 theories.

            As Georg Cantor should have stopped at, "lots".

        • by Bengie ( 1121981 )
          Well, we know that 2 blackholes can merge in a very short human scale finite time and that's just yet another example of information falling into a blackhole.
        • by pz ( 113803 )

          Its not clear it makes sense to talk about what happens to the object inside of the black hole because that is in theory not observable.

          Not observable from the outside, right? But is it not observable from the inside? I mean just because massless photons can't escape doesn't mean they don't exist, right? What I always think of is sort of what you see during a mass coronal ejection on the sun: big looping swaths of particles that don't escape. What does that look like, if you could possibly observe it? Craziness, indeed, but shouldn't it happen? Shouldn't there even be photons orbiting just inside the Schwartzchild radius?

        • Gravity? Did someone say gravity? Didn't Einstein tell us there's no such thing as gravity? It's a distortion in space/time.
          Yet we limit gravity to the speed of light? I mean, we distort space/time at the speed of light!
          Physicists today acknowledge that faster than light communication is possible, and has been performed (quantum entanglement experiments) Yet we still say gravity is at the speed of light. But obversationally we can prove that is not the case. The Earth orbits the Sun and responds to it

    • Comment removed based on user account deletion
      • by Way Smarter Than You ( 6157664 ) on Sunday December 08, 2019 @07:42PM (#59499118)
        I saw the Disney movie. I know the little robot will save us all and we will pass through the black hole to a better place.
        • I saw the Disney movie. I know the little robot will save us all and we will pass through the black hole to a better place.

          I remember that. The black hole was very noisy. While all black holes have dimensions of mass and radius of event horizon, some are massively decibeled.

          • This actually makes sense, I think. Just like the early universe had a density of medium that could propagate compression waves that we could have perceived as sound, there must be a place near a black hole where the matter is similarly dense, and therefore "noisy". And since Bels are measurements of energy, it seems highly likely that it would be very, very loud noise.

            Or am I thinking about this all wrong?

        • Ah, but still will Vincent forever escape the clutches of Max?
      • Agree. The falling person would disintegrate into component parts and begin orbiting the black hole if it were spinning.

        Spaghettification of a star was imaged for the first time in 2018 by researchers observing a pair of colliding galaxies approximately 150 million light-years from Earth.

    • by rossdee ( 243626 )

      "For the person falling, they'd be like, "Hey, no big deal ... I'm hauling ass toward the center." and things would not end well in very short order."

      But with the really big black holes like this one, the tidal stress isn't a problem - you won't be spaghettified. At least not at or around the event horizon. And if you're not falling directly toward the singularity you could last a long time. Radiation might be a problem so keep your shields up...A General Products hull would be useful.

      • Current theory does not have a variable for size. One black hole behaves like another.

      • by Megane ( 129182 )

        A General Products hull would be useful.

        Disclaimer: GP hulls do not block gravity or tidal forces. Please remain in the center of mass during the encounter.

        • by Agripa ( 139780 )

          A General Products hull would be useful.

          Disclaimer: GP hulls do not block gravity or tidal forces. Please remain in the center of mass during the encounter.

          Also consider taking steps to protect your outer integument from starlight.

        • GP hulls have not been tested against black holes nor, if I recall correctly, by impacting a stellar mass of neutronium at relativistic velocities. Somebody did come close to a high gravitational gradient (a neutronium beachball) once while travelling through hyperspace. The GP hull was fine and left hyperspace immediately without further ado. The hyperdrive motor, on the other hand, stayed in hyperspace, and it's exit trajectory is unreported.
    • ... the less you would notice crossing the event horizon. At that size, by the time you'd notice anything im your body, it'd wayyy too late.

      Also, inside a black hole, time and space switch roles. Which is mind-wrecking to even think about.

      I highly recommend PBS SpaceTime on YouTube. They have a load of extremely well-made videos, that explain the craziness of black holes in full detail. (The host is a quasar-researching scientist himself.)

    • For the person falling, they'd be like, "Hey, no big deal ... I'm hauling ass toward the center." and things would not end well in very short order.

      Not sure what you mean by "very short order." For this particular black hole, the Schwartzchild radius is about .12 ly. Even moving at a non-trivial fraction of c, say .01c, it would still take 12 years to reach the singularity.

      • No. Your calculation is linear and your outcome is the bane of many a freshman scientist.

        There are actually two changing variables here. 1.) Velocity and 2.) Gravitational field.

        Your method deals with a straight line and the necessary math produces one half of a quadratic equation where the y axis becomes asymptotic and exponential.

        • No. Your calculation is linear and your outcome is the bane of many a freshman scientist.

          There are actually two changing variables here. 1.) Velocity and 2.) Gravitational field.

          Your method deals with a straight line and the necessary math produces one half of a quadratic equation where the y axis becomes asymptotic and exponential.

          chill, dude. i kept it linear for a reason. you are *way* over-analyzing this.

          • This is Slashdot. The point is being severely under-analyzed.
          • No. Your calculation is linear and your outcome is the bane of many a freshman scientist.

            There are actually two changing variables here. 1.) Velocity and 2.) Gravitational field.

            Your method deals with a straight line and the necessary math produces one half of a quadratic equation where the y axis becomes asymptotic and exponential.

            chill, dude. i kept it linear for a reason. you are *way* over-analyzing this.

            I didn't analyze in any magnitude. I corrected your mistake.

  • Towards us or away from us ?

    • Away, where local velocity is negligible as compared to the total redshift by way of:

      v = Ho d,

      where v is the galaxy's velocity (in km/sec), d is the distance to the galaxy (in megaparsecs; 1 Mpc = 1 million parsecs), and Ho proportionality constant, called "The Hubble constant". ~ Wiki

    • The redshift is z=0.055 for the entire galaxy cluster [u-strasbg.fr], so it'll be travelling away.
  • How is it possible for a bunch of galaxies to collide if they all started at the same point and the rate of acceleration from that point is increasing? All galaxies should be moving apart from all others. No?
    • by ZombieCatInABox ( 5665338 ) on Sunday December 08, 2019 @07:57PM (#59499178)

      The expansion of the universe is not homogeneous.

      Think snowflakes in a snow storm. Ulimately, all snowflakes will obey gravity and end up on the ground. But in the chaos of a storm, even if most flakes move from up to down, some can briefly move in all directions, including up.

      On average, all galaxies are moving away from each other. But in a small localized sample of the universe, galaxies can appear to move in all directions, including towards each other.

      For example, in our own local group, the andromeda galaxy is actually moving towards our own milky way at surprising speed.

      • The expansion of the universe is not homogeneous.

        Think snowflakes in a snow storm. Ulimately, all snowflakes will obey gravity and end up on the ground. But in the chaos of a storm, even if most flakes move from up to down, some can briefly move in all directions, including up.

        On average, all galaxies are moving away from each other. But in a small localized sample of the universe, galaxies can appear to move in all directions, including towards each other.

        For example, in our own local group, the andromeda galaxy is actually moving towards our own milky way at surprising speed.

        Very well put. I am going to plagiarize. :)

      • flakes move from up to down, some can briefly move in all directions, including up..

        Because of wind. Are you saying that gravity in a vacuum results in the same effects of wind in our atmosphere?

      • Hm, ok. But still... how can they move in different directions and speeds much less collide? Everything starts at point zero. Expand out from P0 and velocity V0. V1 > V0. Vx => V(x-1) for all x. Yes? So thus universe is expanding and at ever greater velocity from P0. How does Px and Py ever meet under these circumstances? We don't have wind like with snow flakes causing chaos. I think they -should- all head in a straight line from P0.
        • But still... how can they move in different directions and speeds much less collide?

          The mass is not evenly distributed. So some bits get shot around others, in a slingshot effect.

        • Be careful extrapolating from P0. We don't really know what happened at time zero (I'm not up enough on the theory to even define time zero, either), so you can't really extrapolate from zero, but your analysis after time zero seems sound as far as it goes. However, as drinkypoo said, once the expansion got going the mass was not evenly distributed and some places had local concentrations which allowed gravity to overcome the general expansion of space-time and form gravitationally bound galaxies and clust

    • by meglon ( 1001833 )
      Gravity.
  • more liberal propaganda!
    • Actually, it's based on the scientific method, and not a form of agenda applied to affect political change.

      And, the observations were not taken in Liberal Kansas, pop. 20,000.

  • If this black hole and the galaxy around it is so enormous, why was it not found before every other?
    • by Way Smarter Than You ( 6157664 ) on Sunday December 08, 2019 @10:23PM (#59499594)
      Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
      • by idji ( 984038 )
        Gabest has an ID 10^6, so he should understand that reference and have already known it was the answer to his question. Perhaps he needs to hand in his nerd credentials.
        • by Megane ( 129182 )
          You apparently forgot to escape your '<' (&lt;) and didn't notice it in preview. Hope this helps!
    • Yo momma was in the way.

      • by AntEater ( 16627 )

        Oh dear! I can't believe I had to scroll this far down just to find a "your mom" joke in the comments. Thank you for not disappointing.

    • Because it's a long way away, so it's angular size is small.

      If you actually read any of the papers around the "Event Horizon Telescope" imaging of the surface of a black hole earlier this year, (a big if, I'll grant) you'll remember that the Milky Way's size on the sky (the angular size of Sgr A*) is nearly the same as that of the core SMBH of M87, about 1600 times as far away. So, M87-SMBH is about 1600 times as distant as the core of the Milky Way.

      Clearer now?

  • Comment removed based on user account deletion
  • The universe itself is most likely the biggest black hole of all.
  • 40 billion times the sun's mass? That does not make much sense.

    I would expect it to be no other than 42 billion times the sun's mass.

  • That's Volume 7 of The Art of Computer Programming!

  • Picture or it didn't happen.
  • "...which can kick huge swaths of nearby stars out to the edges..."

    I thought black holes were gravity wells, not repellers.

    "...a monster about as big as our solar system but with the mass of 40 billion suns..."

    What is as big as our solar system? ...the event horizon? ...the singularity itself?

    • Rotating black holes are no different from rotating planets.

      We use planets in the solar system as slingshots.

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