Scientists believe a giant, dying star attempted to swallow the black hole. It didn’t finish well for the stars, new research says.
Supernova: The dramatic end of the life of the star
Supernovae are one of the biggest explosions in the universe, but what causes these explosions?
Accuweather
A new discovery about how the collision between an explosive star, supernova and black holes, could change the way scientists understand the life and death of stars.
This discovery is that astrophysicists have observed the resulting giant stars, which they believe is their interaction with dense black holes. The supernovae were caused by intense gravity stress that attempted to “swallow” the black hole, the study authors say.
This phenomenon can occur more than scientists realize, and a new tool for observing supernova explosions could reveal other examples of black holes that spark supernovae, according to the authors of the lead study.
“If that’s much more common then it would change the way you think about how stars explode,” said Alex Galliano, the research’s lead author and a fellow at the National Science Foundation’s Institute for Artificial Intelligence and Fundamental Interaction.
One of the coolest parts of the discovery is that it was made possible through the use of artificial intelligence, or AI, Gagliano said. AI has helped stars flag stars that operate very early on, allowing teams to closely monitor when amazing events unfold.
The study, published in The Astrophysical Journal, was conducted by a team led by the Center for Astrophysics, a collaboration between Harvard University, the Smithsonian and the Massachusetts Institute of Technology. It is part of a young supernova experiment and wants to discover thousands of new cosmic explosions.
What is a supernova? Black hole?
A supernova is a spectacular explosion of a giant dying star. According to NASA, stars – giant balls of gas – have all life cycles, ranging from millions to trillions of years. When a giant star, several times the mass of the Sun’s mass, flows out of the central nuclear fuel, the force of gravity takes over and suddenly collapses, creating a shock wave that explodes into the supernova.
Supernovae usually leave a very dense core. The very largest supernova leaves behind an infamous black hole for their great mystery. Black holes are a point of the universe, and because of the very strong gravity, they cannot come out even if they are not light, says NASA. Their gravity is very strong as material is confined to small spaces. The black holes are invisible because the light cannot escape, but scientists can find evidence of them when they inhale matter and gas.
Sometimes it is observed that the black hole has a companion star. That is the interaction researcher who has been brought to zero through this new discovery.
Why is this explosive star so special?
The discovery of a supernova called SN 2023ZKD was very unusual as it put together a piece of puzzle that has never been seen before, Gagliano said. Typically, supernova explosions light up for a week or two before reaching peaks, then dim dark, he said.
Initially, the SN 2023ZKD looked like a typical supernova explosion, but at a sudden peak of brightness. However, it then darkened at an unusually slow rate, and the AI program flagged it for further research. Scientists saw decline for several months and then took very strange behavior. It began to lighten again at its second peak.
To understand this, researchers looked back at old archival data and discovered that before the first explosion the star had slowly brightened for about four years. All of these factors pointed to one possible explanation.
Approximately 730 million light years from Earth, SN 2023ZKD is a star trapped in orbital dance by a black hole, and as it gradually approached each other, the black hole pulled the star’s material, gradually causing a glow. At the moment of the explosion, the stars and black holes became very close, and the stars could no longer survive, he said.
Extreme gravity stress from the black hole caused a supernova explosion. A second peak of brightness occurred when the explosion itself collided with a cloud like a leftover disk from the interaction between the star and the black hole.
“It has long been known that most stars have companions who interact with them at some point in their lives…but I really didn’t think this interaction played a leading role in driving the death of the stars,” Galliano said. “It’s very new and exciting and I think it forces me to revisit what I think about simulating the end of the star.”
How AI helps astrophysicists to make new discoveries
The explosion was first discovered in July 2023 after researchers were warned of an unusually slow dimming of the supernova’s glow. The alerts came from an AI program designed to scan the sky for all supernovas, and reports on unusual activity every morning.
The alert allowed the researchers to continue observing the supernova, shockingly beginning to brighten up again, indicating a second explosion.
Without the AI program, the initial explosion might have looked just as observable as many other supernovaes. Gagliano said that from medicine to astrophysics, the role of AI in sifting through mountains of data that human researchers can’t do and flagging abnormally is growing in several scientific fields.
“It is one of the only reasons why we were able to make this discovery and realize that it is scientifically interesting through a combination of machine learning and astrophysics researchers,” he said.
