Black holes are thought of as cosmic leviathans, capable of destroying planets and stars. However, ... [+] in many respects they are essentially just heavy and dark stars.
Fusion in the middle of stars is what powers them. However, eventually fuel runs out. (Photo by: ... [+] QAI Publishing/Universal Images Group via Getty Images)
Eventually, the helium runs out too, and even heavier elements are used to power the nuclear fusion of the star, with oxygen, then silicon, until finally the star is converting its material into iron. And when iron appears, the star runs out of fuel and collapses in on itself, heating up as it collapses, causing a supernova. The outer layers of the star blast off into the cosmos, leaving a remnant.
Many things are taking place:
A supermassive black hole shredded a star and was caught in the act | Science News
Every so often, a celestial slasher film plays out in the heavens, as a supermassive black hole shreds a star and swallows part of it. Now scientists have gotten a rare, early glimpse of the show.
The episode, described September 26 in the Astrophysical Journal , was first detected by telescopes in January and named ASASSN-19bt . It's one of only dozens of these phenomena called tidal disruption events that astronomers have observed.
Such an event, when a star passes close enough to a black hole to get sucked in and torn apart, occurs only about once every 100,000 years in any given galaxy, says Suvi Gezari, an astronomer at the University of Maryland in College Park, who was not involved with the work. "This is really exciting," she says.
See What a Black Hole Would Do to Earth with Online 'Collision Calculator' | Space
And if the black hole harbored 4 million times the mass of the sun, ingesting our poor beleaguered Earth would swell the behemoth's event horizon — the point of no return beyond which nothing, not even light, can escape — by a mere 0.00000000007281%.
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That black hole would be of the supermassive variety, similar in heft to Sagittarius A*, the monster that lurks at the heart of our Milky Way galaxy. But what if we had a run-in with a much smaller black hole — say, one harboring just 20 solar masses? Well, then we'd make more of a dent, causing 0.000014562% event-horizon growth.
Holographic Duality Yields Breakthrough in Black Hole Physics
A group of Skoltech researchers led by Professor Anatoly Dymarsky studied the emergence of generalized thermal ensembles in quantum systems with additional symmetries. As a result, they found that black holes thermalize the same way ordinary matter does. The results of their study were published in Physical Review Letters .
The physics of black holes remains an elusive chapter of modern physics. It is the sharpest point of tension between quantum mechanics and the theory of general relativity. According to quantum mechanics, black holes should behave like other ordinary quantum systems. Yet, there are many ways in which this is problematic from the point of view of Einstein’s theory of general relativity.
While you're here, how about this:
Ask Ethan: How Dense Is A Black Hole?
In April of 2017, all of the telescopes/telescope arrays associated with the Event Horizon Telescope ... [+] pointed at Messier 87. This is what a supermassive black hole looks like, where the event horizon is clearly visible.
I have read that stellar-mass black holes are enormously dense, if you consider the volume of the black hole to be that space which is delineated by the event horizon, but that super-massive black holes are actually much less dense than even our own oceans. I understand that a black hole represents the greatest amount of entropy that can be squeezed into [any] region of space expressed... [so what happens to the density and entropy of two black holes when they merge]?
Astronomers Observe in Incredible Detail a Black Hole Flickering in Our Own Galaxy
A black hole flickering in the Milky Way galaxy has been filmed in unprecedented detail, with a new high frame-rate technique that is helping us understand the wild dynamics of these most enigmatic objects.
The black hole is named MAXI J1820+070, discovered in 2018, roughly 7 times the mass of the Sun and just 10,000 light-years from Earth.
As far as black holes go, it's way small - the lowest mass that we think a black hole can be is around 5 Suns - but there's something else really interesting about it. It's flickering, emitting a whole bunch of X-ray and visible light radiation, as it actively slurps down matter from a nearby star.
The Lowest Mass Black Hole has Been Found, only 3.3 Times the Mass of the Sun - Universe Today
Because of this, astronomers have diligently been trying to create a census of black holes in the Milky Way galaxy for many years. However, new research indicates that astronomers may have overlooked an entire class of black holes. This comes from a recent discovery where a team of astronomers observed a black hole that is just over three Solar masses, making it the smallest black hole discovered to date.
The discovery was especially noteworthy because it identified an object that astrophysicists previously didn't know existed. As a result, scientists are now forced to reconsider what they thought they knew about the population of black holes in our galaxy. As Todd Thompson , a professor of astronomy at The Ohio State University and lead author of the study, explained :
Physicist Builds a Calculator to Show What Would Happen if Earth Collided With a Black Hole
A new online tool calculates just how much cosmic destruction a run-in between the Earth and a black hole would cause.
The aptly-named Black Hole Collision Calculator determines how much a black hole would expand and the amount of energy it would release if it absorbed the Earth — or any other object , since the calculator is totally customizable, Space.com reports .
Particle physicist Álvaro Díez created the tool, which is hosted on the calculator database project Omni Calculator .
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