It’s an exciting time in astronomy today, where records are being broken and reset regularly. We are barely two months into 2024, and already new records have been set for the farthest black hole yet observed, the brightest supernova, and the highest-energy gamma rays from our Sun. Most recently, an international team of astronomers using the ESO’s Very Large Telescope in Chile reportedly saw the brightest object ever observed in the Universe: a quasar (J0529-4351) located about 12 billion light years away that has the fastest-growing supermassive black hole (SMBH) at its center.
Continue reading “The Brightest Object Ever Seen in the Universe”Gravastars are an Alternative Theory to Black Holes. Here's What They'd Look Like
One of the central predictions of general relativity is that in the end, gravity wins. Stars will fuse hydrogen into new elements to fight gravity and can oppose it for a time. Electrons and neutrons exert pressure to counter gravity, but their stability against that constant pull limits the amount of mass a white dwarf or neutron star can have. All of this can be countered by gathering more mass together. Beyond about 3 solar masses, give or take, gravity will overpower all other forces and collapse the mass into a black hole.
Continue reading “Gravastars are an Alternative Theory to Black Holes. Here's What They'd Look Like”Black Holes Existed at the Dawn of Time, Birthing Stars and Encouraging Galaxy Formation
The Universe is full of galaxies, many containing supermassive black holes. That sparked a question: which came first—the galaxies or their black holes? The answer is becoming very clear, thanks to the first year of observations made by the James Webb Space Telescope (JWST). Black holes were in the Universe from the earliest times, along with the very first galaxies. And, they helped shape the cosmos we observe today.
Continue reading “Black Holes Existed at the Dawn of Time, Birthing Stars and Encouraging Galaxy Formation”The Event Horizon Telescope Zooms in on a Black Hole's Jet
Although supermassive black holes are common throughout the Universe, we don’t have many direct images of them. The problem is that while they can have a mass of millions or billions of stars, even the nearest supermassive black holes have tiny apparent sizes. The only direct images we have are those of M87* and Sag A*, and it took a virtual telescope the size of Earth to capture them. But we are still in the early days of the Event Horizon Telescope (EHT), and improvements are being made to the virtual telescope all the time. Which means we are starting to look at more supermassive black holes.
Continue reading “The Event Horizon Telescope Zooms in on a Black Hole's Jet”The Early Universe Had Small Galaxies with Oversized Black Holes
When doing the marketing for the James Webb Space Telescope (JWST), NASA and the other telescope contributors liked to point out how it would open up the early universe to scrutiny. They weren’t exaggerating, and now scientific studies are starting to proliferate that show why. A new study published by authors from Harvard, the University of Arizona, and the University of Cambridge used three surveys produced by the JWST to analyze the supermassive black holes at the center of early galaxies. And they found they were much different than the one at the center of our own, at least in terms of relative size.
Continue reading “The Early Universe Had Small Galaxies with Oversized Black Holes”A Black Hole Has Cleared Out Its Neighbourhood
We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion.
But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood.
Continue reading “A Black Hole Has Cleared Out Its Neighbourhood”It's a Fine Line Between a Black Hole Energy Factory and a Black Hole Bomb
Black holes are powerful gravitational engines. So you might imagine that there must be a way to extract energy from them given the chance, and you’d be right. Certainly, we could tap into all the heat and kinetic energy of a black hole’s accretion disk and jets, but even if all you had was a black hole in empty space, you could still extract energy from a trick known as the Penrose process.
Continue reading “It's a Fine Line Between a Black Hole Energy Factory and a Black Hole Bomb”Webb Sees Dozens Of Young Quasars in the First Billion Years of the Universe
Within almost every galaxy is a supermassive black hole. Millions, sometimes billions of solar masses locked within an event horizon of space and time. They can power luminous quasars, drive star formation, and change the evolution of a galaxy. Because of their size and abundance, supermassive black holes must have formed early in cosmic history. But how early is still an unanswered question. It’s a focus of a recent study on the arXiv.
Continue reading “Webb Sees Dozens Of Young Quasars in the First Billion Years of the Universe”This is the Oldest Black Hole Ever Seen
There’s an incredibly ancient black hole out there that’s challenging astronomers to explain how it could exist only 400 million years after the Big Bang. It’s at the heart of a galaxy called GN-z11. Astronomers using JWST saw evidence of it gobbling up that galaxy, which is one way a black hole can grow.
Continue reading “This is the Oldest Black Hole Ever Seen”M87*'s Event Horizon Image. One Year Later
Fifty-five million light years from Earth there is a massive elliptical galaxy known as Messier 87, or M87 for short. It was cataloged by Charles Messier in the 1700s, along with 102 other fuzzy objects in the sky that were definitely not comets. It was confirmed to be a galaxy in the early 1900s, and by the mid-twentieth century, it was known to be a powerful radio source. But these days it is most widely known for the supermassive black hole deep in its core. Called M87*, it is the first black hole directly observed by astronomers. The first image of M87* was released in 2019, and was based on observations taken by the Event Horizon Telescope (EHT) in 2017. Now a new image based on 2018 data has been released. The similarities and differences between the two images tell us a great deal about M87* and black holes in general.
Continue reading “M87*'s Event Horizon Image. One Year Later”