We don’t quite understand how the first supermassive black holes formed so quickly in the young universe. So a team of physicists are proposing a radical idea. Instead of forming black holes through the usual death-of-a-massive-start route, instead giant dark matter halos directly collapsed, forming the seeds of the first great black holes.Continue reading “How did Supermassive Black Holes Form? Collapsing Dark Matter Halos can Explain Them”
On its own, a black hole is remarkably easy to describe. The only observable properties a black hole has are its mass, its electric charge (usually zero), and its rotation, or spin. It doesn’t matter how a black hole forms. In the end, all black holes have the same general structure. Which is odd when you think about it. Throw enough iron and rock together and you get a planet. Throw together hydrogen and helium, and you can make a star. But you could throw together grass cuttings, bubble gum, and old Harry Potter books, and you would get the same kind of black hole that you’d get if you just used pure hydrogen.Continue reading “Hawking Made a Prediction About Black Holes, and Physicists Just Confirmed it”
Gravitational-wave detectors have been a part of astronomy for several years now, and they’ve given us a wealth of information about black holes and what happens when they merge. Gravitational-wave astronomy is still in its infancy, and we are still very limited in the type of gravitational waves we can observe. But that could change soon.Continue reading “Gravitational-Wave Detector Could Sense Merging Primordial Black Holes With the Mass of a Planet, Millions of Light-Years Away”
Back in 2019, the world was treated to the first ever image of a black hole, which was originally captured in 2017. The feat was widely heralded as a leap forward for astrophysics, supporting Einstein’s Theory of Relativity. Now a team led by the Radboud University proposes sending instruments into space to estimate black hole parameters more accurately by an order of magnitude. The newest paper, led by Dr. Volodymyr Kudriashov, translates science goals into technical requirements and focuses on the instrumentation needed for the Event Horizon Imager, as the mission is called.Continue reading “Space Telescopes Could Provide Next-Level Images of Black Hole Event Horizons”
Black holes are the most powerful destructive forces in the universe. They can rip apart a star and scatter its ashes out of the galaxy at nearly the speed of light. But these engines of destruction can also pave the way for new stars to form, as a new study in Nature shows.Continue reading “Black Holes don't Just Destroy, They Also Help With Star Formation”
Astronomers recently caught a supermassive black hole gulp down a star. It flared in exactly the same way as its smaller cousins do when those black holes have a snack. It just took longer and was a million times brighter.Continue reading “Whether They’re Stellar-Mass or Supermassive, Black Holes Behave Pretty Much the Same Way”
Why are black holes so alluring?
You could cite plenty of reasons: They’re matter-gobbling monsters, making them the perfect plot device for a Disney movie. They warp spacetime, demonstrating weird implications of general relativity. They’re so massive that inside a boundary known as the event horizon, nothing — not even light — can escape its gravitational grip.
But perhaps the most intriguing feature of black holes is their sheer mystery. Because of the rules of relativity, no one can report what happens inside the boundaries of a black hole.
“We could experience all the crazy stuff that’s going on inside a black hole, but we’d never be able to tell anybody,” radio astronomer Heino Falcke said. “We want to know what’s going on there, but we can’t.”
Falcke and his colleagues in the international Event Horizon Telescope project lifted the veil just a bit two years ago when they released the first picture ever taken of a supermassive black hole’s shadow. But the enduring mystery is a major theme in Falcke’s new book about the EHT quest, “Light in the Darkness: Black Holes, the Universe, and Us” — and in the latest installment of the Fiction Science podcast, which focuses on the intersection of fact and science fiction.Continue reading “Scientist sees deep meaning in black holes after Event Horizon Telescope’s triumph”
In 2019 the Event Horizon Telescope (EHT) gave us the first direct image of a black hole. On one hand, the image it produced was rather unimpressive. Just a circular blur of light surrounding a dark central region. On the other hand, subtle characteristics of the image hold tremendous information about the size and rotation of the black hole. Most of the details of the black hole image are blurred by the limits of the EHT. But the next generation EHT should provide a sharper view, and could reveal the dark edge of a black hole’s event horizon.Continue reading “What Comes After Photographing a Black Hole's Event Horizon? Could we see the Photon Ring?”
Sometimes astronomers come up with awesome names for certain phenomena and then feel like they can’t use them in formal scientific contexts. Tidal Disruption Events (TDEs) are one of those – colloquially they are known as “spaghettifications” where a star is pulled apart until its constituent matter looks like a string of spaghetti.
Astronomers have long known of this process, which takes place when a star gets too close to a black hole, but most of that knowledge has come through studying radiation bursts emitted by the blackhole as it devoured the star. Now, a team led by Giacomo Cannizzaro and Peter Jonker from SRON, the Netherlands Institute for Space Research, and Radboud University now think they have captured the first glimpses of a star actively being spaghettified around the pole of a black hole.Continue reading “Are we Seeing a Star That Just got Spaghettified?”
In theory, a black hole is easy to make. Simply take a lump of matter, squeeze it into a sphere with a radius smaller than the Schwarzschild radius, and poof! You have a black hole. In practice, things aren’t so easy. When you squeeze matter, it pushes back, so it takes a star’s worth of weight to squeeze hard enough. Because of this, it’s generally thought that even the smallest black holes must be at least 5 solar masses in size. But a recent study shows the lower bound might be even smaller.Continue reading “Smallest, Closest Black Hole Ever Discovered is Only 1,500 Light-Years Away”