Scientists have succeeded in solving the mystery of when black holes “burp”; That is, when these astronomical bodies release flows and jets after feeding on the stars, throwing materials to huge distances into space.
Black holes are objects of extreme density, to the point that their gravity becomes, at a certain moment, too strong to allow light or matter to escape from them. These boundaries of no return are known as the “event horizon”; The point from which escape requires traveling at a speed exceeding the speed of light.
Despite their reputation as cosmic sinkholes, black holes are actually “very chaotic feeding organisms,” according to Dr. Adele Goodwin, an astrophysicist at Curtin University in Western Australia.
She added: “You have to get very close to the black hole to reach the event horizon, while stars are destroyed in areas much farther away than that.”
Scientists know, from rare observations of stars being torn apart by black holes - a process that involves an effect known as “macroscopic expansion” - that “only about half the volume of a star that gets very close to a black hole ends up being swallowed into the black hole,” according to Goodwin.
As for the rest of the material, it is released back into space in the form of powerful jets and flows, which are sometimes so huge that they can “affect the development of the entire galaxy,” she said. “You can think of it as a burp from a black hole,” she explained.
But the timing of these burps was previously a mystery to astrophysicists. “It sometimes happened a year after the black hole destroyed the star, and sometimes after 3 or 5 years.”
In new research published in the journal Nature Astronomy, Goodwin and co-researcher Dr. Andrew Mummery, from the Institute for Advanced Studies, expressed their belief that they have found the answer, by using radio telescopes to study 20 tidal disturbance events. These are cases in which supermassive black holes devour stars.
“Radio waves are the only frequency at which we can observe jets and flows as they move outward,” Goodwin explained.
The researchers concluded that supermassive black holes, whose sizes range from hundreds of thousands to billions of times the mass of our Sun, fire powerful jets in two distinct phases of their feeding cycle.
The first occurs when a black hole is feeding at very high rates. The second occurs hundreds to thousands of days after the star is first torn apart, when the feeding rate drops to about 2 percent of the maximum rate at which the black hole can swallow material.
It is known that this same limit stimulates burps from stellar-mass black holes; They are much smaller objects, with a mass of about 10 to 50 times the mass of our sun.
The research showed that black holes release jets at the same point in their feeding cycle, regardless of their size, according to Goodwin. She stressed that this discovery will enable scientists to accurately predict the timing of the launch of such jets, which narrows observation windows and saves valuable time for using telescopes.
“We can really begin to understand not only when the jets are fired, but also how powerful they are, and whether that depends on the properties of the black hole,” she added.
For her part, Dr. Sarah Webb, an astrophysicist at Swinburne University, said: “We are still trying to solve the basic mysteries of the most extreme objects in the universe. Supermassive black holes.
Webb explained that the study showed “that supermassive black holes behave quite predictably in two separate stages of their evolution,” and that the researchers “connected this to what we have previously observed regarding black holes with a much smaller stellar mass.”
From a small drawing drawn by a five-year-old child, a personal story began that accompanied Johnny Depp for years, before it was finally transformed into a bronze sculpture about two meters high. The American star reveals his first experiences in the world of sculpture through his work “The Bunnyman,” which will be displayed at the Contemporary Istanbul Contemporary Art Exhibition in Turkey, between September 22 and 27.
The work, made of white bronze, bears the features of a character that combines the form of a human and a rabbit, and appears as a mysterious guard carrying what is known as the “Sword of Truth.” The sculpture will stand outdoors inside the historic “Istanbul Arsenal”, a former Ottoman shipyard on the banks of the Golden Horn, as part of one of the exhibition’s special projects.
However, the value of the “Rabbit Man” for Depp does not stop at its strange appearance or its striking presence in public space. The character carries a personal story dating back to his childhood and his relationship with his son Jack. The artist was inspired to work from a drawing that his son had drawn when he was about five years old, which is approximately the same age that Deeb was when, as he says, he had a recurring dream that remained stuck in his memory.
Since then, the character has become a recurring part of Depp's artistic world, appearing in a number of his drawings, paintings and prints, before taking a three-dimensional form for the first time and moving from paper to sculpture.
The sculpture was executed in cooperation with Pantheon Art, which manages Depp’s artistic works, while the Fondaria Artistica Battaglia foundry in Milan handled its casting. The unveiling of the work comes at a time when Depp’s artistic activity is witnessing an increasing presence, in conjunction with his exhibition “A Bunch of Stuff” held at the Museum of Modern Art in Shanghai, which includes more than 200 artworks.
This step does not represent the beginning of Deeb’s relationship with fine art, as he had previously experimented in the field of artistic publications. In 2022, his first collection of printed works achieved great demand and sold out in less than 24 hours.
Between cinema, painting and sculpture, Depp seems to continue building his own artistic world, but his choice of “Rabbit Man” as his first sculptural work carries a different meaning. This time, it is not about a movie character or a picture of an international star, but rather a memory that started from a child’s drawing and an old dream, before finding its way, years later, to a bronze piece that now stands in the heart of Istanbul.
Australian police said that a man was killed today (Friday) after he was attacked by a shark while swimming at a popular beach in the state of Western Australia.
The incident is the latest in a series of shark attacks witnessed in the country, and comes a few days after a surfer was bitten by a shark in the same state.
Western Australia Police said that emergency services were called to deal with a report of an incident linked to a shark in the waters off Sorrento Beach, at about 10:30 am local time.
The police said in a statement: “It was reported that a man was bitten by a shark while swimming near the coast.” The statement added that the authorities launched a massive search operation by air and sea, but the swimmer died as a result of the attack.
Sorrento Beach is a popular swimming destination, and is located about 20 kilometers from Perth's central business district.
The local council said it closed all beaches within its jurisdiction after the attack.
The “Shark Smart” platform, which specializes in monitoring sharks, received a report of the sighting of a 5-meter white shark near the neighboring Buinabot Reef shortly after noon today (Friday). It has not been confirmed whether this is the same shark that attacked the swimmer today.
On Monday, a surfer was attacked on a beach in the city of Geraldton, located about 400 kilometers north of Perth. Local media reported that he lost one of his feet and suffered serious injuries to his leg.
This comes after a 35-year-old man was killed while spearfishing off the state's south coast in June, and another 38-year-old man was killed after a shark attack on an island near Perth in May.
