Keyword: blackholes

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  • Cosmic zombies: Black holes can reanimate dead stars

    08/31/2018 9:14:04 AM PDT · by ETL · 20 replies
    Space.com ^ | August 30, 2018 | Mike Wall, Space.com Senior Writer
    Close encounters with medium-size black holes can reanimate dead stars, if only momentarily, a new study suggests. A team of astronomers performed computer simulations to determine what happens when a burned-out stellar corpse known as a white dwarf passes close to an intermediate-mass black hole — one that harbors between 1,000 and 10,000 times the mass of Earth's sun. The researchers determined that the black hole's powerful gravity can stretch and distort the white dwarf's previously inert innards so dramatically that nuclear-fusion processes can reignite for a few seconds, converting helium, carbon and oxygen into heavier elements such as iron....
  • Researchers Find Source of Strange 'Negative' Gravity

    08/13/2018 3:41:56 PM PDT · by plain talk · 84 replies
    LiveScience ^ | August 10, 2018 | Rafi Letzler
    Sound has negative mass, and all around you it's drifting up, up and away — albeit very slowly. That's the conclusion of a paper submitted on July 23 to the preprint journal arXiv, and it shatters the conventional understanding that researchers have long had of sound waves: as massless ripples that zip through matter, giving molecules a shove but ultimately balancing any forward or upward motion with an equal and opposite downward motion. That's a straightforward model that will explain the behavior of sound in most circumstances, but it's not quite true, the new paper argues. A phonon — a...
  • The Next Big Discovery in Astronomy? We Probably Found It Years Ago...

    06/03/2018 9:18:47 AM PDT · by LibWhacker · 27 replies
    Space.com ^ | 6/3/18 | Eileen Meyer
    The Next Big Discovery in Astronomy? We Probably Found It Years Ago — But Don't Know It Yet By Eileen Meyer, University of Maryland, Baltimore County | June 3, 2018 08:44am ET MORE An artist's illustration of a black hole "eating" a star.Credit: NASA/JPL-Caltech This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights. Earlier this year, astronomers stumbled upon a fascinating finding: Thousands of black holes likely exist near the center of our galaxy. The X-ray images that enabled this discovery weren't from some state-of-the-art new telescope. Nor were...
  • Mathematicians Disprove Conjecture Made to Save Black Holes

    05/19/2018 7:14:18 AM PDT · by LibWhacker · 36 replies
    Quanta Magazine ^ | 5/17/18 | Kevin Hartnett
    Nearly 40 years after it was proposed, mathematicians have settled one of the most profound questions in the study of general relativity. In a paper posted online last fall, mathematicians Mihalis Dafermos and Jonathan Luk have proven that the strong cosmic censorship conjecture, which concerns the strange inner workings of black holes, is false.“I personally view this work as a tremendous achievement — a qualitative jump in our understanding of general relativity,” emailed Igor Rodnianski, a mathematician at Princeton University.The strong cosmic censorship conjecture was proposed in 1979 by the influential physicist Roger Penrose. It was meant as a...
  • Astronomers Spy Swarms of Black Holes at Our Galaxy's Core

    04/04/2018 12:39:19 PM PDT · by LibWhacker · 31 replies
    Scientific American ^ | 4/4/18 | Lee Billings
    Anticipated but never before seen, the existence of tens of thousands of these dark objects at the galactic center could have far-reaching implications for astrophysics An artist's rendering of the Milky Way's core, with a supermassive black hole at its center. Scientists have discovered what appear to be twelve smaller black holes orbiting our galaxy's central giant. Each is thought to actually be a binary system composed of a black hole and a low-mass star. Gas siphoned from the star glows in x-rays as it falls into the black holes, allowing them to be seen. Credit: Columbia University For the...
  • Massive black hole 100,000 times bigger than the Sun discovered

    09/11/2017 8:29:48 AM PDT · by ETL · 42 replies
    The Sun, via FoxNews.com/Science ^ | September 08, 2017 | Aletha Adu
    An immense black hole 100,000 times bigger than the sun has been discovered at the heart of the Milky Way. The enormous void, which lies around 25,000 light years from Earth, could help scientists uncover the how stars, galaxies and even life itself came to be in the universe. ..." According to reports, this newly-discovered black hole could rank as the second largest ever seen in the Milky Way. Despite its immense size, scientists have called it a "mini me" version of its super-massive "cousin" known as Sagittitarius A*.
  • Gravitational Lensing Provides Rare Glimpse Into Interiors of Black Holes

    08/18/2017 12:16:04 AM PDT · by LibWhacker · 2 replies
    Universe Today ^ | 8/17/17 | Matt Williams
    Gravitational Lensing Provides Rare Glimpse Into Interiors of Black Holes Article written: 17 Aug , 2017 by Matt Williams The observable Universe is an extremely big place, measuring an estimated 91 billion light-years in diameter. As a result, astronomers are forced to rely on powerful instruments to see faraway objects. But even these are sometimes limited, and must be paired with a technique known as gravitational lensing. This involves relying on a large distribution of matter (a galaxy or star) to magnify the light coming from a distant object.Using this technique, an international team led by researchers from the California...
  • LIGO Continues To Make Waves in Gravitational Wave Detection Physics

    06/25/2017 6:28:56 AM PDT · by Lonesome in Massachussets · 14 replies
    American Physical Society ^ | June 1, 2017 | Rachel Gaal
    The Laser Interferometer Gravitational-wave Observatory (LIGO) continues to make waves within the physics community. On June 1, they published their third gravitational wave detection from an observation in early January 2017. This new detection may help vet previously established theories of how these massive mergers behave, and has already provided a new round of observational data to push forward this new kind of astronomy. The confirmed results, published in Physical Review Letters, tell a story of two black holes that coalesced 3 billion light-years from Earth. So far, this is the farthest source from which gravitational waves have been detected...
  • Black holes could be 'back doors' to other parts of the universe, claim scientists

    08/05/2016 10:43:13 AM PDT · by b4its2late · 51 replies
    UK Mirror ^ | 5 Aug 2016 | John von Radowitz
    Black holes could be "back doors" to other regions of the universe, a new study suggests. However, it is unlikely anyone passing through one of the gateways would survive, say scientists. First they would be "spaghettified" - stretched out like a strand of pasta - by the black hole's immense gravity. Once on the other side of the "door" the traveller would be compacted back to normal size, but could not count on being restored back to life.
  • Mystery Solved: Black Holes Twist Space-Time Like Taffy

    08/01/2016 9:20:39 AM PDT · by BenLurkin · 12 replies
    space.com ^ | July 30, 2016 07:48am ET
    The story starts in the 1980s, when astronomers found that small (stellar-mass) black holes emit X-ray light that flickers in a curious pattern. At first, this flickering occurs every few seconds; however, the time between each flicker shortens over the course of a few months, eventually stopping completely. This "quasi-periodic oscillation" (QPO) was thought to be a result of a phenomenon predicted by Albert Einstein's theory of general relativity — that any object with enough mass, like a black hole, will twist space-time as it spins. Later, scientists calculated that these gravitational vortices will cause the orbits of particles around...
  • Astronomy Picture of the Day -- GW151226: A Second Confirmed Source of Gravitational Radiation

    06/15/2016 1:43:27 PM PDT · by SunkenCiv · 12 replies
    NASA ^ | Wednesday, June 15, 2016 | (see photo credit)
    Explanation: A new sky is becoming visible. When you look up, you see the sky as it appears in light -- electromagnetic radiation. But just over the past year, humanity has begun to see our once-familiar sky as it appears in a different type of radiation -- gravitational radiation. Today, the LIGO collaboration is reporting the detection of GW151226, the second confirmed flash of gravitational radiation after GW150914, the historic first detection registered three months earlier. As its name implies, GW151226 was recorded in late December of 2015. It was detected simultaneously by both LIGO facilities in Washington and Louisiana,...
  • Supermassive black holes in 'red geyser' galaxies cause galactic warming

    05/30/2016 4:08:50 PM PDT · by JimSEA · 37 replies
    Science Daily ^ | 5/25/2016 | University of Kentucky
    An international team of scientists, including the University of Kentucky's Renbin Yan, have uncovered a new class of galaxies, called "red geysers," with supermassive black hole winds so hot and energetic that stars can't form. Over the last few billion years, a mysterious kind of "galactic warming" has caused many galaxies to change from a lively place where new stars formed every now and then to a quiet place devoid of fresh young stars. But the mechanism that produces this dramatic transformation and keeps galaxies quiet has been one of the biggest unsolved mysteries in galaxy evolution. "These galaxies have...
  • Hawking at Harvard ... tackles the contradictory qualities of black holes

    05/10/2016 1:00:09 AM PDT · by LibWhacker · 15 replies
    Harvard.edu ^ | 4/18/16 | Peter Reuell
    Hawking at Harvard At packed Sanders Theatre, theoretical physicist and cosmologist tackles the contradictory qualities of black holes April 18, 2016 | Editor's Pick Popular Stephanie Mitchell/Harvard Staff Photographer"If determinism — the predictability of the universe — breaks down in black holes, it could break down in other situations. Even worse, if determinism breaks down, we can’t be sure of our past history either. The history books and our memories could just be illusions. It is the past that tells us who we are. Without it, we lose our identity," said Stephen Hawking. By Peter Reuell, Harvard Staff Writer Twitter...
  • Astrophysicists detect ultra-fast winds near supermassive black hole

    03/24/2016 12:44:16 PM PDT · by Red Badger · 22 replies
    phys.org ^ | March 21, 2016 | Provided by: York University
    Artist's illustration of turbulent winds of gas swirling around a black hole. Some of the gas is spiraling inward, but some is being blown away. Credit: NASA, and M. Weiss (Chandra X -ray Center) ============================================================================================================================================== New research led by astrophysicists at York University has revealed the fastest winds ever seen at ultraviolet wavelengths near a supermassive black hole. "We're talking wind speeds of 20 per cent the speed of light, which is more than 200 million kilometres an hour. That's equivalent to a category 77 hurricane," says Jesse Rogerson, who led the research as part of his PhD thesis in...
  • Cosmic rays fired at Earth – now we know where from

    03/17/2016 9:55:45 AM PDT · by LibWhacker · 33 replies
    Cosmos ^ | 3/17/16 | Bill Condie
    Cosmic rays fired at Earth - now we know where from The violent region at the centre of our galaxy is the prime candidate, after gamma ray analysis, Bill Condie reports. Photo montage of gamma-rays as measured by the HESS array on the night sky over Namibia, with one of the small HESS telescopes in the foreground. Credit: H.E.S.S. Collaboration, Fabio Acero and Henning Gast Astronomers believe they may have identified the source of the stream of cosmic rays that rain down on Earth from outer space. Cosmic rays are extremely high-energy particles such as protons and atomic nuclei....
  • Clocking the Extreme Spin of a Monster Black Hole

    03/17/2016 6:36:54 PM PDT · by MtnClimber · 22 replies
    D-News ^ | 15 Mar, 2016 | IAN O'NEILL
    upermassive black holes are the most extreme objects in the known universe, with masses millions or even billions of times the mass of our sun. Now astronomers have been able to study one of these behemoths inside a strange, distant quasar and they’ve made an astonishing discovery — it’s spinning one-third the speed of light. Studying a supermassive black hole some 3.5 billion light-years away is no easy feat, but this isn’t a regular object: it’s a quasar that shows quasi-periodic brightening events every 12 years or so — a fact that has helped astronomers reveal its extreme nature. Quasars...
  • Are Supermassive Black Holes Hiding Matter?

    02/29/2016 10:00:38 PM PST · by BenLurkin · 26 replies
    universetoday.com ^ |  29 Feb , 2016 | Matt Williams
    [S]cientists...for some time now, they have been working with a model that states that the Universe consists of 4.9% “normal” matter (i.e. that which we can see), 26.8% “dark matter” (that which we can’t), and 68.3% “dark energy”. From what they have observed, scientists have also concluded that the normal matter in the Universe is concentrated in web-like filaments, which make up about 20% of the Universe by volume. But a recent study performed by the Institute of Astro- and Particle Physics at the University of Innsbruck in Austria has found that a surprising amount of normal matter may live...
  • ASTRONOMERS JUST SNAPPED PHOTOS OF THE MOST MASSIVE BLACK HOLE WE’VE EVER OBSERVED

    02/18/2016 10:44:57 AM PST · by LibWhacker · 53 replies
    Digital Trends ^ | 2/17/16 | Chloe Olewitz
    A new photograph of galaxy NGC 4889 may look peaceful from such a great distance, but it’s actually home to one of the biggest black holes that astronomers have ever identified. The Hubble Space Telescope allowed scientists to capture photos of the galaxy, located in the Coma Cluster about 300 million light-years away. The supermassive black hole hidden away in NGC 4889 breaks all kinds of records, even though it is currently classified as dormant. So how big is it, exactly? Well, according to our best estimates, the supermassive black hole is roughly 21 billion times the size of the...
  • Galactic center's gamma rays unlikely to originate from dark matter, evidence shows

    02/05/2016 1:08:03 PM PST · by MtnClimber · 15 replies
    Princeton University ^ | 4 Feb, 2016 | Catherine Zandonella, Office of the Dean for Research
    Bursts of gamma rays from the center of our galaxy are not likely to be signals of dark matter but rather other astrophysical phenomena such as fast-rotating stars called millisecond pulsars, according to two new studies, one from a team based at Princeton University and the Massachusetts Institute of Technology and another based in the Netherlands. Previous studies suggested that gamma rays coming from the dense region of space in the inner Milky Way galaxy could be caused when invisible dark matter particles collide. But using new statistical analysis methods, the two research teams independently found that the gamma ray...
  • Dark matter and the dinosaur: New theory challenges notions on origins of human life

    12/12/2015 1:32:59 AM PST · by Squawk 8888 · 22 replies
    National Post ^ | December 12, 2015 | Joseph Brean
    TORONTO — Dark matter inspires many strange theories, but until now few have involved giant lizards and the origins of humanity. If physicist Lisa Randall’s theory is correct, however, there is a clear link between dark matter, the great unknown majority of universal stuff and the extinction of the dinosaurs, which cleared the path for the rise of mammals, including that special species, homo sapiens. Roughly, her idea is that the rotation of a vast disc of dark matter through our solar system dislodged an asteroid from a weak and distant orbit, and sent it hurtling toward Earth, where it...