Astronomers working with NASA’s Neil Gehrels Swift Observatory have spotted something unusual. The observatory’s X-Ray Telescope (XRT) has captured emissions from a supermassive black hole (SMBH) in a galaxy about 500 million light-years away. The black hole is repeatedly feeding on an unfortunate star that came too close.Continue reading “A Black Hole Nibbles on a Star Every 22 Days, Slowly Consuming it”
In astronomy, we speak casually of extremely large numbers and extremely vast distances as if they’re trivial. A supermassive black hole can have several billion solar masses, a distant quasar is 500 million light-years away, etc. Objects like galaxies that are mere tens of millions of light years away start to seem familiar.
But even though our Wikipedia pages are full of data on distant objects, there’s a deceptive lack of understanding of some of their basic properties. Take Messier 87, for example, a galaxy often talked about and seen in images. It’s noteworthy for being home to the first black hole ever imaged.
It’s so far away that astronomers have no real idea what its three-dimensional shape is.Continue reading “M87 Galaxy Reconstructed in Thrilling 3D”
Supermassive black holes (SMBHs) lurk in the center of large galaxies like ours. From their commanding position in the galaxy’s heart, they feed on gas, dust, stars, and anything else that strays too close, growing more massive as time passes. But in rare circumstances, an SMBH can be forced out of its position and hurtle through space as a rogue SMBH.Continue reading “Astronomers Spot a Rogue Supermassive Black Hole, Hurtling Through Space Leaving Star Formation in its Wake”
Black holes swallow everything—including light—which explains why we can’t see them. But we can observe their immediate surroundings and learn about them. And when they’re on a feeding binge, their surroundings become even more luminous and observable.
This increased luminosity allowed astronomers to find a black hole that was feasting on material only 800 million years after the Universe began.Continue reading “Hungry Black Hole was Already Feasting 800 Million Years After the Big Bang”
The death of a star is one of the most dramatic natural events in the Universe. Some stars die in dramatic supernova explosions, leaving nebulae behind as shimmering remnants of their former splendour. Some simply wither away as their hydrogen runs out, billowing into a red giant as they do so.
But others are consumed by behemoth black holes, and as they’re destroyed, the black hole’s powerful gravity tears the star apart and draws its gas into a donut-shaped ring around the black hole.Continue reading “The Donut That Used To Be a Star”
Something extraordinary happens about every 10,000 to 100,000 years in galaxies like the Milky Way. An unwary star approaches the supermassive black hole (SMBH) at the galaxy’s center and is torn apart by the SMBH’s overpowering gravity. Astronomers call the phenomenon a tidal disruption event (TDE.)
Usually, a TDE spells doom for the star as its gas is torn away into the black hole’s accretion ring, causing a bright flaring visible for hundreds of millions of light years. But researchers have found one black hole that’s playing with its food.Continue reading “A Black Hole is Savoring its Meal, Feeding on the Same Star Over and Over Again”
When a flash of light appears somewhere in the sky, astronomers notice. When it appears in a region of the sky not known to host a stellar object that’s flashed before, they really sit up and take notice. In astronomical parlance, objects that emit flashing light are called transients.
Earlier this year, astronomers spotted a transient that flashed with the light of a trillion Suns.Continue reading “A Black Hole Consumed a Star and Released the Light of a Trillion Suns”
Researchers using the IceCube Neutrino Observatory have detected neutrinos emanating from the energetic core of an active galaxy millions of light-years away. Neutrinos are difficult to detect, and finding them originating from the galaxy is a significant development. What does the discovery mean?Continue reading “IceCube Senses Neutrinos Streaming From an Active Galaxy 47 Million Light-Years Away”
At the edge of known space are quasars. They are powerful cosmic engines capable of creating intense beams of light across billions of light years. And they are powered by supermassive black holes (SMBHs). Most galaxies have a SMBH, including our own galaxy, but for quasars to be so powerful their SMBHs must have become very large very quickly. We’re still learning just how they formed. We’ve long thought their formation involved a special set of circumstances, but a new study shows that early quasars could have formed purely from cold dark gas.Continue reading “Supermassive Black Holes Formed Directly out of Enormous Streams of Cold gas”
One of the key aspects of galactic evolution is star production. On a basic level, stars form within a galaxy’s gas and dust all the time, and where they form can help determine a galaxy’s shape and size. But there seems to be a sweet point when star production in a galaxy is particularly strong. Galaxies often have a period of rapid star production which then drops off. Astronomers are still trying to understand what causes this drop-off.Continue reading “Supermassive Black Holes Shut Down Star Formation”