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Scientists Discover Teeny Tiny Black Hole 277

Posted by Zonk
from the for-relative-terms-of-teeny-and-tiny dept.
AbsoluteXyro writes "According to a Space.com article, NASA scientists have discovered the smallest known black hole to date. The object is known as 'XTE J1650-500'. Weighing in at a scant 3.8 solar masses and measuring only 15 miles across, this finding sheds new light on the lower limit of black hole sizes and the critical threshold at which a star will become a black hole upon its death, rather than a neutron star. XTE J1650-500 beats out the previous record holder, GRO 1655-40, by about 2.5 solar masses."
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Scientists Discover Teeny Tiny Black Hole

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  • by Anonymous Coward on Wednesday April 02, 2008 @06:05PM (#22945880)
    They say LHC-001 will be even smaller!

    (But who will be there to measure...?)
    • Re: (Score:3, Informative)

      by Compholio (770966)

      Is it smaller than this one [newscloud.com]?
      Not even close, do you really think that we could make a 3.8 solar mass black hole in the lab (that's several hundred thousand times the mass of our planet)? A more accurate term for the kind of black hole we might make in the lab is the hypothetical "microsingularity".
  • Looks like now we have a small black hole for our youngest planet [slashdot.org]
  • by Anonymous Coward
    Is this the point where they say we'll need to re-think our theories on black hole evapouration too? But first, let's switch on the LHC and see what happens...
  • by Anonymous Coward on Wednesday April 02, 2008 @06:08PM (#22945924)
    HILARITY!
  • by cryptoluddite (658517) on Wednesday April 02, 2008 @06:10PM (#22945948)
    I see we weren't the first to build a large hadron collider.
  • by Anonymous Coward on Wednesday April 02, 2008 @06:14PM (#22945984)
    It may look cute now. But they grow up.
  • Size vs Age (Score:5, Interesting)

    by SKiRgE (411560) on Wednesday April 02, 2008 @06:15PM (#22945996)
    While it may be possible that this black hole was formed from a relatively small (to form a black hole) star, couldn't it also be the case that it just a really old black hole? Hawkings told of how black holes can 'evaporate' over time with lack of surrounding matter, perhaps that could be the case here.
    • Re: (Score:3, Informative)

      Possible, but I believe they evaporate over the course of trillions of years via Hawking radiation. Based on recent evidence, the universe is only old enough for it to still have been the smallest yet discovered.

      At least, if I were a scientist and not someone pulling this directly out of my ass, that might be what is happening here.
      • Possible, but I believe they evaporate over the course of trillions of years via Hawking radiation. Based on recent evidence, the universe is only old enough for it to still have been the smallest yet discovered.

        It would be really interesting if we eventually found a class of black holes which could only predate the big bang.

    • Re:Size vs Age (Score:5, Informative)

      by smolloy (1250188) on Wednesday April 02, 2008 @06:32PM (#22946170)
      It is true that black holes will evaporate over time, but they will also gain mass from infalling matter.

      But!

      The temperature of a black hole can be defined by the rate at which Hawking photons are streaming away from it. In the case of a black hole of a few solar masses, this temperature will be in the nano-Kelvin (I think -- don't hurt me if I'm wrong by a few orders of magnitude). Now remember everything in the Universe is sitting in a bath of cold photons from the Big Bang (i.e. the microwave background). These photons have a temperature of ~4 Kelvin.

      Therefore, black holes whose Hawking temperature is above the microwave background will be net *gaining* mass.

      Which is all a long way of saying, no, this isn't a normal size black hole that has decayed over time. It must have been created at this mass (or smaller).

      • Re: (Score:2, Interesting)

        by Anonymous Coward
        I get 16.4 nano-Kelvin for a 3.8 solar mass black hole. Nice guess.

        So the CMBR at 2.7 Kelvin is about 165 million times warmer than this black hole.

        Now as an academic aside, assuming the universe doesn't end in either a big rip or a big crunch, but rather a disappointing heat death, eventually the matter and energy in the universe would be so diffuse due to ordinary expansion that the temperature would drop below that 16.4 nano-Kelvin, and the hole would start losing mass. Over probably close to a goo
        • Re: (Score:2, Interesting)

          by smolloy (1250188)
          Since we're doing an academic exercise here, let's imagine the situation from the point of view of something falling into the black hole. If this something was looking backwards (i.e. out at the Universe, and not towards its impending doom), it would see all incoming photons strongly blue-shifted. To someone watching it fall into the black hole, they'd see it becoming more and more red-shifted, and slowing down more and more, until it appears to freeze, infinitely red-shifted, on the surface of the even
      • I take it you mean below, so any black hole above a certain size threshold won't decay until they eat all the background radiation in the universe. This size, presumeably, is above the lower limit for black hole creation in a supernova.
    • Has the Hawking radiation been observed? I thought it was still a hypothesis.
    • Yes, but the evaporation process is extremely slow. The following is an excerpt from the wiki article on Hawking Radiation [wikipedia.org]:

      For a black hole of one solar mass (about 2 × 10^30 kg), we get an evaporation time of 10^67 years--much longer than the current age of the universe.

      So even though this hole is evaporating like any other it could not have been much larger at the time of its formation (although it might have been somewhat smaller depending upon how much mass it has sucked in during its existence so far), even if it had existed since the beginning of the Universe which is impossible because stars, and especially lower mass stars like the one that mos

    • by shma (863063)
      No, the time it takes for a stellar black hole to evaporate is much, much longer [wikipedia.org] than the age of the universe, even assuming that no matter is falling into it. For a mass this large, the time is on the order of 10^69 years. It is only microscopic black holes that decay quickly. For instance, if we take a proton-proton collision at the LHC, where each proton has an energy of 7 TeV, and form a black hole out of it, it would have a mass of 10^-23 kilograms and would evaporate in 10^-84 seconds, which is the
    • You're close to the correct reasoning. What has actually happened here is that the black hole in question has simply had wave after wave of matter thrown at it until it hit it's preset kill limit.

      Once that occurs, the black hole shuts down and it's simply a matter of time until it evaporates into nothing.

      I believe the final thing that appeared to enter the hole and allow it to reach it's kill limit was a space cruise ship, Tita-something or other. Closely followed by an upper-class-looking golden robot. I t
  • Goldilocks (Score:5, Funny)

    by Dopamine, Redacted (1244524) on Wednesday April 02, 2008 @06:16PM (#22946016)
    So, we've now discovered the biggest and smallest black holes known to exist within about a week of each other.

    When we find the most average, space bears will come and blast us into porridge.

    Astronomy kicks ass.
  • First extra-solar Large Hadron Collider discovered.
  • untrue statement (Score:5, Interesting)

    by ILuvRamen (1026668) on Wednesday April 02, 2008 @06:20PM (#22946056)
    They can't figure out the "critical threshold" because there isn't one. It all depends on too many variables to set a universal limit (hehehe get it...universal :-P) It depends on how much nuclear activity there is still going on when it start collapsing and what the amount of heavier atoms is and the amount of other things orbiting the star and any other forces affecting the star at that time and how fast it's moving and spinning. Mass is a smaller part of the calculation than they're making it sound like. If they're going to factor everything in just to find some minimum mass, well duh, two particles and a hell of a lot of force. Haven't they suggested that in that big particle accelerator aka donut of doom. So yeah, a critical mass threshold doesn't exist.
  • by syousef (465911) on Wednesday April 02, 2008 @06:31PM (#22946162) Journal
    For those of you who haven't done any Astrophysics...

    http://en.wikipedia.org/wiki/Chandrasekhar_limit [wikipedia.org]
    • by esampson (223745)
      I believe according to the link you sent that the Chandrasekhar limit is the upper limit for how massive a non-rotating star can be before it collapses into a black hole (there are obviously plenty of stars with more mass than this but they have rotation or other things that prevent them from collapsing). What the article is talking about is a theoretical lower limit for how small something can be before naturally forming into a black hole. This is not necessarily the same since you could have a smaller bod
      • by syousef (465911)
        I've studied Astronomy. The Chandrasekhar limit is a classic piece of Astrophysics that should be part of any popular article discussing the limiting size of an object becoming a black hole. I don't know of a mechanism that might cause a smaller body to form a black hole. That force would need to be applied in such a way as to overcome electron degeneracy pressure.

        1.4 solar masses is much smaller than the masses we're observing for black holes. My point was we haven't approached this yet. There are other fo
  • by nick_davison (217681) on Wednesday April 02, 2008 @06:56PM (#22946432)

    "this finding sheds new light"
    I'm pretty sure it doesn't.
  • The smallest blackhole is Uranus.

    Thank you, thank you - I'm here all week. The lasagna's great - tip your waitress...

    :-)

    RS

  • "That's not a black hole, it's a space station!"
  • It's not the size of your black hole that matters, it's how you manage your singularity.

  • Slownewsday:

    Shaposhnikov and his colleague Lev Titarchuk of George Mason University used this method to "weigh" XTE J1650-500 and found a mass of 3.8 suns. This value is well below the previous record holder GRO 1655-40, which tips the scales at about 6.3 suns.
    Call me when they make that black hole using that collider they talk about in a different comment.
  • Atkins? (Score:2, Funny)

    by JeffSchwab (1159723) *
    I'd love to know XTE J1650-500's secret. I've tried diet and exercise, but I'm still only down to 3.9 solar masses and 16 miles across.

Nothing will dispel enthusiasm like a small admission fee. -- Kim Hubbard

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