November 4th, 2011
03:44 PM ET

Hubble observes black hole's accretion disc

What does a black hole look like? Scientists have, for the first time, directly observed the disc that surrounds this area of tremendous gravitational pull, from which no light can escape.

Black holes power quasars, which are thought to be the extremely bright centers of certain galaxies surrounding supermassive black holes. Scientists believe that large amounts of energy are released when matter falls into a black hole, producing the light of the quasar. Around a black hole is an accretion disk, made of dust and gas.

The thing about quasars, though, is that they're so far from Earth that even at a typical size of 100 billion kilometers across, they appear so small to us that there will probably never be a telescope powerful enough to see their structures directly. That in turn means that most of our knowledge of quasars' inner structure is theoretical – not based on direct observations.

In order to learn more about the nature of these still-largely-mysterious objects, then, astronomers had to devise a new way to study quasars. That's exactly what they've done with the Hubble Space Telescope: They used the stars in a galaxy as a scanning microscope. The gravitational lensing of these stars amplifies the light from different parts of the quasar itself, resulting in detailed color information for a line through the accretion disc.

By combining several images produced using this technique, astronomers were able to see subtle color differences over the observation times, which translates to a full color profile across the black hole's accretion disc. The color profile in turn allowed the team to determine that the disc is between 100 to 300 billion kilometers across – a wide range, to be sure, but still incredibly accurate given the incredible distance between the relatively small quasar and Earth.

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Filed under: Discoveries • In Space • News
soundoff (19 Responses)
  1. Alex

    Why doesn't the acretion disk fall into the black hole? Why isn't it just a hole?

    November 30, 2011 at 10:15 am |
  2. Dean

    I hate to be the ingnorant one commenting, but I have a question that has plagued me for a long time. If Einstein truly did, mathematically, prove that nothing moves faster than light, and light never escapes a black hole, then doesnt it stand to reason that whatever physics is keeping light from escaping a black hole has to involve something moving faster than light?

    November 11, 2011 at 1:02 pm |
    • peabody

      no, it does not. and a better way of looking at einstein's calculations is to say that they are limited to objects with mass traveling below the speed of light. unless you like playing with limits that don't exist and imaginary numbers. But if you like i, I'd suggest playing with the frequency domain.

      November 11, 2011 at 2:52 pm |
    • James

      No, black holes don't require any velocity nevermind super-cee velocity to gobble up light.

      To put it into something you can visualise, think of the black hole as an ACTUAL HOLE in an otherwise (relatively) flat surface like say a pool table. Think of the beam of light as an exceedingly fast pool ball.

      The hole in the table has a sharp exponential funnel curve into it.

      In order to trap and hold the fast-moving pool ball the hole does not require any velocity. As long as the ball does not hit the rim of the funnel at a sufficient velocity and off-angle to run the rim and skip/slingshot back out it is doomed to be trapped regardless of how fast the hole may or may not be moving relative to the ball.

      November 11, 2011 at 8:48 pm |
  3. TurnLeadIntoGold

    I like black holes. But gravitational lensing is just to personal. So don't try to lens my hole and we'll becool

    November 10, 2011 at 10:22 pm |
    • OneOfNineKids

      Black holes are more likely to go to prison than white holes.
      Black Holes are constantly trying to suck EVERYTHING in.
      Black Holes Are Well BLACK
      just some facts for those interested.

      November 10, 2011 at 10:25 pm |
      • James

        *Black Hole* (in a high-pitched voice of Flip Wilson)...why, what's yo name? What in the hell you want comin' round here in them ships?

        November 22, 2011 at 1:20 pm |
  4. Lorenzo

    Personally I think it is awesome and I'd like o thank the folks at CNN for taking an interest in things like this. I find it interesting and if I can't be a part of the discoveries that are on the horizon I would at least like to be kept in the loop about what is going on around the world and beyond. I am eager to see what new discoveries are waiting just over the horizon.

    November 8, 2011 at 3:24 pm |
  5. jesco

    blesphemy! those are just the headlights of Jesus's pickup truck as he speeds towards Earth blastin' Hank Williams Jr.! Everyone knows science is evil!

    November 8, 2011 at 11:58 am |
  6. SamSkwirl

    I..for one... think black holes and white holes should remain segregated.

    November 8, 2011 at 11:18 am |
  7. Hatch

    Hooraaay for SCIENCE!! Always keep growing and inspiring the search for TRUTH. Give the "nay-sayers" nowhere to go. 'Nuff said.

    November 8, 2011 at 10:37 am |
  8. appapo

    "...between 100 to 300 billion kilometers across"; Good estimate, isn't it?

    November 7, 2011 at 10:06 pm |
    • Junius Gallio

      It's a far better estimate than was had before.

      November 7, 2011 at 10:20 pm |
    • Lokari

      Yes, actually, remarkably good, considering how far away these objects are.

      November 8, 2011 at 2:04 am |
  9. Amber

    wow! i really wish i would've done better in school and went into the science field!! I would LOVE to go into space as my "work" πŸ™‚ black holes are something that i still barely understand, it would be very cool if we could find out more information on these in the future πŸ™‚

    November 4, 2011 at 3:57 pm |
    • Juniys Gallio

      Agreed! Don't get me wrong, I love my job ... but working in space, or even in the space program, would be terrific.

      November 4, 2011 at 9:34 pm |
    • James

      It is never too late to pursue your dreams and interests.

      December 1, 2011 at 12:23 am |
      • Amber

        you're so right. thanks for thinking i still can. πŸ™‚ who knows, maybe you'll see me up there one day!

        December 6, 2011 at 1:55 pm |
  10. Gavin

    That is so awesome! Gravitational lensing is amazing.

    November 4, 2011 at 3:47 pm |


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