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Black Hole Awakens After 26 Years

Posted by samzenpus on from the go-back-to-sleep dept.

schwit1 writes: For the first time since 1989, the black hole in V404 Cygni, a system comprising a black hole and a star, has reawakened, suddenly emitting high energy outbursts beginning on June 15. The outbursts are probably occurring because the black hole is gobbling up material that has fallen into it. While the 1989 outburst helped astronomers gain their first understand of the behavior of a black hole in a star system, this outburst will help them understand how such systems evolve and change over time. The European Space Agency (ESA) reports: "First signs of renewed activity in V404 Cygni were spotted by the Burst Alert Telescope on NASA's Swift satellite, detecting a sudden burst of gamma rays, and then triggering observations with its X-ray telescope. Soon after, MAXI (Monitor of All-sky X-ray Image), part of the Japanese Experiment Module on the International Space Station, observed an X-ray flare from the same patch of the sky. These first detections triggered a massive campaign of observations from ground-based telescopes and from space-based observatories, to monitor V404 Cygni at many different wavelengths across the electromagnetic spectrum."

36 of 58 comments (clear)

  1. Status: OK by Sneeka2 · · Score: 2

    V200 Cygni

    There, FTFY.

    --
    Bitten Apples are still better than dirty Windows...
  2. Black Hole "Awakens" by Anonymous Coward · · Score: 1

    That is not dead which can eternal lie,
    And with strange aeons even death may die.

  3. I hate the term "awakens" by jfdavis668 · · Score: 4, Insightful

    The black hole just sat there. Something else collided with it, and the black hole gravity pulled it in. The something, probably a gas cloud, heated up during the fall and started to emit radiation. How does this cause something to wake up?

    1. Re:I hate the term "awakens" by Psychotria · · Score: 4, Funny

      The something, probably a gas cloud [...] How does this cause something to wake up?

      I dunno about you, but if someone farted in my face while I was sleeping I'd probably wake up as well.

    2. Re:I hate the term "awakens" by Anonymous Coward · · Score: 1

      Because by your own words, it was just sitting there. Now its doing something. It woke up. Its like waking up a laptop, yes it wasn't really asleep because it doesn't dream. Its called language, learn to use it motherfucker.

    3. Re:I hate the term "awakens" by NicknameUnavailable · · Score: 1

      Its like waking up a laptop, yes it wasn't really asleep because it doesn't dream. Its called language, learn to use it motherfucker.

      Google would beg to differ. It's called language, learn to use it motherfucker.

    4. Re:I hate the term "awakens" by m.alessandrini · · Score: 1

      Also, the black hole "being seated" somewhere is not so exact as well...

    5. Re:I hate the term "awakens" by CBM · · Score: 4, Informative

      Actually the term is appropriate. Gravity doesn't disappear, but material can orbit the black hole in an accretion disk, in a dormant state. When enough material builds up in the disk, accretion flow to the black hole can activate. It's called an accretion disk instability. In the astronomy business we would say the black hole has become active, or is having a transient outburst, but awaken is fine for public consumption.

  4. being an old hand on slashdot by nimbius · · Score: 4, Funny

    Im pleasantly surprised the words 'black hole awakens after 26 years' isn't followed up with some sort of infuriating article on SCO.

    --
    Good people go to bed earlier.
    1. Re:being an old hand on slashdot by Sneeka2 · · Score: 4, Funny

      No worries, that's a different kind of 'hole.

      --
      Bitten Apples are still better than dirty Windows...
  5. Watch a movie of V404 Cyg in the optical by StupendousMan · · Score: 4, Informative

    I've been using our university's observatory to take images of V404 Cyg for the past week. On Jun 23/24, the star underwent a particularly crazy series of variations: over a period of six hours, it fell to just 5 percent of its initial brightness, then recovered almost to its starting point.

    I made an animated GIF showing the star's changes over this period. You can see it on my observing log for the the night:

    http://spiff.rit.edu/richmond/...

    That page also includes my full dataset, and pointers to additional reading.

    The star is currently bright enough -- mag 11-14 -- to be studied easily with small telescopes. Anyone interested in joining the effort should start with the American Association of Variable Star Observers (AAVSO) -- go to their campaign page at

    http://www.aavso.org/aavso-ale...

    --
    Michael Richmond "This is the heart that broke my finger."
    mwrsps@rit.edu http://stupendous.rit.edu
    1. Re:Watch a movie of V404 Cyg in the optical by StupendousMan · · Score: 4, Interesting

      Good idea. We astronomers try to eliminate such possibilities by measuring OTHER stars nearby and comparing their variations to those of the target. In this case, nearby stars didn't vary over the night, so we can rule out clouds in the Earth's atmosphere, which would have affected them all.

      Now, it's possible that a cloud near the star itself could have something to do with this variation .... but the timescale for motions of such big objects is almost always far longer than a few hours. So, it's more likely that the variations are due to changes in the luminosity of the accretion disk around the black hole than to the motions of a big obscuring cloud in this case.

      --
      Michael Richmond "This is the heart that broke my finger."
      mwrsps@rit.edu http://stupendous.rit.edu
    2. Re:Watch a movie of V404 Cyg in the optical by StupendousMan · · Score: 2

      My apologies. I should have marked the position of the variable star. I've just modified the web page so that the initial picture indicates the target -- click on that initial picture to see the movie. Thanks for pointing that out.


      since you're doing such extensive image processing anyway, why not correct for the blooming of bright stars and make them all the same size and shape?

      Well, in part, because I'm an astronomer, not a cinematographer, so my ability to make nice movies is rather limited. I could claim that there's some pedagogical value in seeing the ugly nature of the real scientific images, but, actually, that would just be covering up for the fact that I'm lazy.

      --
      Michael Richmond "This is the heart that broke my finger."
      mwrsps@rit.edu http://stupendous.rit.edu
    3. Re:Watch a movie of V404 Cyg in the optical by funwithBSD · · Score: 2

      Error: V404 Not Found

      --
      Never answer an anonymous letter. - Yogi Berra
  6. Re:Easy by moronoxyd · · Score: 1

    It's always sucking, but there needs to be something there for it to suck for it to suck something.

    But... that doesn't make sense.
    Either it's always sucking, then it is also sucking when there is nothing to be sucked in.
    Or it is only sucking when there is something to be sucked in, then it isn't always sucking.

    I wish we had somebody who could analyze this further. Somebody who specializes in black holes and their suckiness. Maybe in astronomic bodies in general. We could call those specialists 'astronomers'.

  7. The real importance of the event by m.alessandrini · · Score: 2

    IANAA, but I think the exceptional thing here is that such a huge change in an astronomical object can be seen in an human-life time scale, instead of millions years as usual.

    1. Re:The real importance of the event by CBM · · Score: 2

      Well yes and no. There are probably hundreds of thousands of these systems, lying dormant, in our galaxy. Each one is probably fed by a nearby orbiting donor star, that transfers matter in a slow trickle to an accretion disk which surrounds the black hole. The material kind of stays there, dormant, in the disk. When enough density builds up in the accretion disk, there is an hydrodynamic instability that causes flow to suddenly turn on. This will flush out the disk, the system will eventually turn off after a few months, and then it will lie dormant again. The time scale for recurrence could be a year, it could be thousands of years; it kind of depends on the mass transfer rate from the donor star and the mass of the black hole. There are typically tens of black hole outbursts per year in our galaxy, but V404 Cyg is one of the brightest known.

  8. Sloppy language by argStyopa · · Score: 3, Interesting

    Even in TFA, using the term 'reawakened' is so totally mischaracterizing the situation.

    It's not like black holes go dormant, or gravity goes to sleep. No, clearly it's been short of significant infall material and has suddenly consumed something substantial, leading to a burst of outflow energy.

    It's interesting and fascinating, but really we can do better to inform the general public (who is already woefully scientifically ignorant) than using tabloid-level language to explain it.

    Obligatory relevant xkcd: https://xkcd.com/1133/ 'Up goer five'

    --
    -Styopa
    1. Re:Sloppy language by CBM · · Score: 4, Interesting

      Actually, yes, black hole *systems* go dormant. The system consists of the black hole itself, but also an accretion disk orbiting the black hole, and also an orbiting donor star which is providing a relatively steady flow of matter to the outer part of the accretion disk.

      Matter can stay there, in the accretion disk for a year, tens of years, or thousands of years, until enough mass density builds up. At that point, an accretion disk instability turns on and you get a transient outburst, and then it will take a few months to flush out the disk.

      Google for "dwarf nova instability."

  9. Re:Jun 15....7800 years ago by m.alessandrini · · Score: 1

    Can we stop making this clarification? WE KNOW!

  10. Old news by Anonymous Coward · · Score: 2, Funny

    Pfft ... this happened 7800 years ago ... go /.

    1. Re:Old news by davester666 · · Score: 1

      It was just resting before continuing on with the main course...that much turkey will put anyone to sleep for awhile...

      --
      Sleep your way to a whiter smile...date a dentist!
  11. Ve Arr Gohing sthrooooo!!! by tekrat · · Score: 1

    Someone send Maximillian and VINcent to check it out....

    --
    If telephones are outlawed, then only outlaws will have telephones.
    1. Re:Ve Arr Gohing sthrooooo!!! by Chris+Mattern · · Score: 1

      No, that was thirty-six years ago.

  12. Um, seems like it revived 7800 years ago by mpercy · · Score: 1

    And our scientists just got around to noticing last week?

  13. Moonsized space station? by mpercy · · Score: 1

    Maybe?

  14. Of course... by TechNeilogy · · Score: 1

    ...it actually woke up a long, long time ago.

    --
    "The wisdom of the Patriarchs was that they *knew* they were fools." --Master Foo
  15. Re:Jun 15....7800 years ago by Translation+Error · · Score: 1

    Jun 15....7800 years ago. That's when we aware, actually event occurred when civilization here on Earth was in its infancy.

    You mean it's out of it now?!

    --
    When someone says, "Any fool can see ..." they're usually exactly right.
  16. The scary part is... by Gondola · · Score: 1

    If an event like this were to happen "near" us in astronomical terms, and we were in the (very, very large) path of lethal radiation, we would simply be exterminated. Bruce Willis could not save us.

  17. As I said before by Muad'Dave · · Score: 1

    As I said in my biopic, The Sleeper Has Awakened!

    --
    Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
  18. Well, not exactly current events by blackanvil · · Score: 1

    I'm just amused because this "current" increase in energy output actually happened about 7,800 years ago, and we're just now getting the news.

    1. Re:Well, not exactly current events by Hognoxious · · Score: 2

      By slashdot's standards that's good. It can take almost as long for events happening on the other side of the Earth.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
  19. Short time by m1c4a1 · · Score: 1

    What's 26 years for a black hole? An eye-blink?

  20. Re:Jun 15....7800 years ago by MobileTatsu-NJG · · Score: 1

    Are we supposed to congratulate you for having watched Star Trek?

    --

    "I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)

  21. Re:Jun 15....7800 years ago by amRadioHed · · Score: 1

    It's wrong anyways. In our frame of reference the event just occurred.

    --
    We hope your rules and wisdom choke you / Now we are one in everlasting peace
  22. Omnomnomnom by Tyr07 · · Score: 1

    Black holes also apparently emit sound. Isn't that an eerie thought? Frequency is astronomically low though.

    http://www.nasa.gov/centers/go...