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Space

Telescopes Record Last Moments of Star Devoured By a Black Hole (scitechdaily.com) 40

A reader shares a report from SciTechDaily: Using telescopes from the European Southern Observatory (ESO) and other organizations around the world, astronomers have spotted a rare blast of light from a star being ripped apart by a supermassive black hole. The phenomenon, known as a tidal disruption event, is the closest such flare recorded to date at just over 215 million light-years from Earth, and has been studied in unprecedented detail. The research is published today in Monthly Notices of the Royal Astronomical Society.

"We found that, when a black hole devours a star, it can launch a powerful blast of material outwards that obstructs our view," explains Samantha Oates, also at the University of Birmingham. This happens because the energy released as the black hole eats up stellar material propels the star's debris outwards. The discovery was possible because the tidal disruption event the team studied, AT2019qiz, was found just a short time after the star was ripped apart. "Because we caught it early, we could actually see the curtain of dust and debris being drawn up as the black hole launched a powerful outflow of material with velocities up to 10 000 km/s," says Kate Alexander, NASA Einstein Fellow at Northwestern University in the US. "This unique 'peek behind the curtain' provided the first opportunity to pinpoint the origin of the obscuring material and follow in real time how it engulfs the black hole."

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Telescopes Record Last Moments of Star Devoured By a Black Hole

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  • Only recently confirmed to exist, black holes seem to be everywhere all of a sudden. There could even be a low-mass one in our solar system. There could be many adrift on the fringes of spiral galaxies like ours. If only we could harness one and do freaky shit with it like time dilation, effectively traveling into the future.
    • There could even be a low-mass one in our solar system.

      There is no known mechanism for the formation of black holes smaller than about 3 solar masses.

      The smallest known BH is 3.8 SMs.

      Any BH smaller than 3 SMs could only have formed in the first few nanoseconds of the Big Bang but would have required far bigger asymmetries than the observed CMB.

      • There could even be a low-mass one in our solar system.

        There is no known mechanism for the formation of black holes smaller than about 3 solar masses...

        says the last human, just before the event.

        Seems Nigel Tufnel got his answer as to what happens when you turn the Hadron Collider up to 11...

      • No known natural way, yes. But artificial ones could be theoretically made [wikipedia.org].
        • To create a BH that would be stable for even one second, we would need to increase the power of the LHC by 28 orders of magnitude. Each particle would need the energy of 500 million Hiroshima bombs.

          • Problem is, that wouldn’t work. The thermal pressure isn’t so easy to overcome. That’s why it’s “easier” to do with em radiation, though you would need something the size of a star to pull it off, you could keep making them over and over. A few million metric tons of mass outta do it so yea, more like 31 orders of magnitude more. But the big benefit is you could use them as the ultimate power source for just about anything.
      • You're reversing the timeline.

        The CMB happened 380,000 years after the big bang.

        The microscopic black holes would have formed before that time.

        • The Universe became transparent to light, including IR, about 380,000 years after the BB when the plasma coalesced into atoms.

          At that point, the CMB would have shown any preexisting asymmetries in the distribution of mass.

          The distribution was not perfectly uniform, but nowhere near distorted enough to create primordial BHs.

          It is not impossible that some primordial BHs exist, but both the CMB and observational evidence of the present universe, suggest that they do not.

          So if your plan is to snag a small BH fr

    • "Only recently confirmed to exist, germs seem to be everywhere all of a sudden. There could even be a mass of them in your kitchen. There could be many adrift in the street outside. If only we could harness one and do freaky shit with it like vaccines, effectively erasing disease."

    • , effectively traveling into the future.

      Traveling into the future is easy. Just wait.

      • Yeah, but some people are impatient. Besides, it's currently impossible for anyone to wait more than about 100 years, and even that requires a lot of luck. Hardly anything really interesting happens on such such time scales.

    • It doesn't work the way you think it does.

      You're referring to the "Twin Paradox," where one twin stays home and another takes off at near-light speeds and returns.

      The traveler claims to have been gone only a few years and the stay-at-home is much older.

      Neither twin did anything remotely similar to "time travel."

      The stay at home lived a normal life throughout their time and the traveler experienced a normally-paced trip.

      The home twin can share stories about her past, but that past is not part of the travel

    • If only we could harness one and do freaky shit with it

      I suppose Rule 34 applies to astronomy too. Just don't come crying to me when your junk gets torn off or your urologist can't find it when it's a singularity.

  • by backslashdot ( 95548 ) on Tuesday October 13, 2020 @03:29AM (#60601984)

    I felt a great disturbance in the Gravitational Force, as if millions of voices suddenly cried out in terror and were suddenly silenced.

    • Was that a statement from LIGO ?

    • The civilization that lived on a planet orbiting that star realized it was going to happen long ago. They put together a great project to build space arks and transport everyone to a new home world. They will arrive here sometime next week.
  • by excelsior_gr ( 969383 ) on Tuesday October 13, 2020 @06:26AM (#60602258)

    Because we caught it early, we could actually see the curtain of dust and debris [...]

    Early?! Dude, you're actually 215 million years too late!

    On a more serious note, can someone who actually knows this stuff tell us how long such phenomena last? Does the star get consumed within minutes, years, decades or what? Of course I understant that all these time-frames are nothing compared to the lifetime of a star, but how long does it take for it to dissappear in a black hole? Does it depend on size?

    • Re:Early?! (Score:5, Informative)

      by fazig ( 2909523 ) on Tuesday October 13, 2020 @07:24AM (#60602352)
      What they supposedly caught on their sensors was a tidal disruption flare, which is supposed to happen at the start of such a process. I am not sure how long this particular process (that tidal disruption event) would last. But you're asking for something different in your post.

      From what I understand, it could take billions of years from the perspective of an outside observer until all of the matter from what used to be a star has fallen onto the singularity.
      Factors for the possible duration of should be size, distance, relative velocity vectors.

      Since when we're asking a question of "how long" we're talking about time and have to understand that space time quite curved around such a massive object occupying a relatively tiny space as a black hole. The closer an objects gets to such a strongly curved space time, the slower time moves forward for an outside observer.

      Here it's also important to remember that objects around a black hole can exist in a stable orbit. In that regard black holes are no different than any other massive object, 'orbital speed' exists unless you get so close that this orbital speed would exceed the speed of light, which for all we know is impossible to be achieved by an object with a rest mass > 0.
      If your velocity is slower than that given your distance to the massive object, you'll fall into the massive object. If the velocity is higher you'd drift away.
      • Re:Early?! (Score:4, Interesting)

        by Immerman ( 2627577 ) on Tuesday October 13, 2020 @10:23AM (#60602904)

        >If the velocity is higher you'd drift away.
        Not quite.

        If your velocity is higher than needed for a circular orbit given your current position, you'll still be on an elliptical orbit.

        If your velocity is higher than an elliptical orbit can constrain, then you're traveling faster than escape velocity and will depart on a hyperbolic or (very unlikely) parabolic trajectory and will depart from the region without circling the black hole even once.

        • To nitpick (and not to take away from your answer), the parabolic part of the trajectory disappears once the object reaches escape velocity. It becomes a straight line, barring influences from other nearby massive objects.

          Good answer, though.

          • Umm, no - escape velocity is what puts it on the parabolic trajectory (or more likely hyperbolic - parabolic only applies to the special case when you're traveling at *exactly* escape velocity)

            The trajectory itself doesn't become straight (barring other influences) until you leave the gravitational influence of the primary, at infinite distance. Though obviously it gets pretty close to straight long before then. Critically, it's distance that straightens the path, not speed. So long as there's any gravit

        • by fazig ( 2909523 )
          I'll take it.

          My intention is mostly to dispell that still circulating myth that black holes are something super special that eventually will 'devour' everything that comes near them.
          • And a good intention it is.

            I try to keep it simple: A black hole behaves exactly like any other massive object, until the moment you actually touch the event horizon.

  • a star being ripped apart by a supermassive black hole

    That sounds vaguely like certain specialty deep fake sexual fetish sites.

  • Total clickbait. Seriously? You recorded the last moments and you just had to put a Hollywood spin on it.

    • The article is not clickbait but I share your disdain for "an artist's rendition."

      If the authors want to include explanatory graphics that work to explain, then OK.

      The teaser image is often a waste of time.

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