Space and astronomy news
In September 2022, an automated sky survey detected what seemed to be a supernova explosion about one billion light-years away. The Zwicky Transient Facility (ZTF) spotted it and gave it the name AT2022tsd. But something was different about this supernova. Supernovae explode and shine brightly for months, while AT2022tsd exploded brightly and then faded within days.
Continue reading “Can a Dead Star Keep Exploding?”
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”
When a black hole consumes a star, things can get quite messy. Take, for example, the event known as ASASSN-14li, where a massive star strayed too close to a supermassive black hole and paid the ultimate price.
Continue reading “A Giant Black Hole Destroyed a Star and Threw the Pieces Into Space”
It’s a tale as old as time. A cataclysmic event occurs in the universe and releases a tremendous amount of energy in a short period of time. The event then fades into the darkness and the cosmos returns to normal. These short-lived cosmic events are known as transients and include things such as supernovae and gamma-ray bursts. Transients are quite common, but some of them can challenge explanations. Take for example the transient known as ZTF20abrbeie, nicknamed Scary Barbie.
Continue reading “What a Mess. A Black Hole's Stellar Meal is Brighter and Longer Lasting Than Ever Seen Before”
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”
Black holes are confounding objects that stretch physics to its limits. The most massive ones lurk in the centers of large galaxies like ours. They dominate the galactic center, and when a star gets too close, the black hole’s powerful gravitational force tears the star apart as they feed on it. Not even the most massive stars can resist.
But supermassive black holes (SMBHs) didn’t start out that massive. They attained their gargantuan mass by accreting material over vast spans of time and by merging with other black holes.
There are large voids in our understanding of how SMBHs grow and evolve, and one way astrophysicists fill those voids is by watching black holes as they consume stars.
Continue reading “A Star Came too Close to a Black Hole. It Didn’t End Well”
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”
Originally predicted by Einstein’s Theory of General Relativity, black holes are the most extreme object in the known Universe. These objects form when stars reach the end of their life cycle, blow off their outer layers, and are so gravitationally powerful that nothing (not even light) can escape their surfaces. They are also of interest because they allow astronomers to observe the laws of physics under the most extreme conditions. Periodically, these gravitational behemoths will devoir stars and other objects in their vicinity, releasing tremendous amounts of light and radiation.
In October 2018, astronomers witnessed one such event when observing a black hole in a galaxy located 665 million light-years from Earth. While astronomers have witnessed events like this before, another team from the Harvard & Smithsonian Center for Astrophysics noticed something unprecedented when they examined the same black hole three years later. As they explained in a recent study, the black hole was shining very brightly because it was ejecting (or “burping”) leftover material from the star at half the speed of light. Their findings could provide new clues about how black holes feed and grow over time.
Continue reading “A Black Hole Burps out Material, Years After Feasting on a Star”
Supermassive black holes (SMBH) reside in the center of galaxies like the Milky Way. They are mind-bogglingly massive, ranging from 1 million to 10 billion solar masses. Their smaller brethren, intermediate-mass black holes (IMBH), ranging between 100 and 100,000 solar masses, are harder to find.
Astronomers have spotted an intermediate-mass black hole destroying a star that got too close. They’ve learned a lot from their observations and hope to find even more of these black holes. Observing more of them may lead to understanding how SMBHs got so massive.
Continue reading “Astronomers Discover an Intermediate-Mass Black Hole as it Destroys a Star”