A dying star is shedding a massive sphere of dust and gas approximately half the size of our solar system. Astronomers are puzzled by this phenomenon as there’s no known process capable of producing such an extensive amount of material from a single star.
Red supergiants are the universe’s largest stars, representing the final stages of a massive star that has exhausted most of its fuel before it eventually goes supernova. During this brief phase, the star expands rapidly, releasing copious amounts of gas and dust and forming bubbles around it.
Mark Siebert from the Chalmers Institute of Technology in Sweden and his colleagues found that the red supergiant star DFK 52 possesses the largest known environment for such celestial bodies, creating a bubble 50,000 times wider than the distance between Earth and the Sun. Curiously, these stars are relatively dim, suggesting they have less energy than what would typically be needed to generate such a vast debris field. “I can’t ascertain how I can disperse so much material in that timeframe,” Siebert remarks.
Previously, DFK 52 had been observed by various telescopes, allowing astronomers to conclude that it expelled a normal quantity of gas. However, when Siebert and his team used the Atacama Large Millimeter Array (ALMA) in Chile, they detected light at longer wavelengths from older, much cooler materials.
“It reveals an extensive environment around DFK 52 with a very complex geometry that’s not entirely understood yet,” Siebert explains. “We don’t grasp the precise structure, but we acknowledge its immense scale.”
Similar to the intricate flow of bubbles throughout the structure, Siebert and his team observed ring-like formations at the core of the overall sphere, expanding at approximately 30 kilometers per second. They estimate that this activity likely stemmed from a significant event that occurred around 4,000 years ago, potentially key to understanding how the star generated so much material.
Location of DFK 52 observed by the Spitzer Space Telescope
NASA/JPL-CALTECH/IPAC
A potential explanation for the extensive environment is that these stars may have briefly increased in brightness and then dramatically faded, although red supergiants are not typically known for such fluctuations, according to Siebert. Alternatively, another star may be orbiting a larger star, stripping material from DFK 52, but this would likely result in a more symmetrical bubble, Siebert asserts. “It is evident that some additional energy sources must contribute to this phenomenon, but we remain uncertain about what they are,” he comments.
“The explosion won’t alter the star’s overall evolution, but it may significantly influence the future appearances of supernovas,” says Emma Beads from John Moores University, Liverpool, UK. “This is an intriguing development that enhances our understanding of unusual supernovae.”
World Capital of Astronomy: Chile
Discover the astronomical wonders of Chile. Visit some of the world’s most advanced observatories and experience the pristine night sky.
Enthusiasts of Marvel movies and comics might recognize the tale of Thor’s Hammer, Mjolnir. This metal was crafted from the core of a dying star. While the power of the God of Thunder is not accessible to anyone, some of the heavy metals around us might originate from a long-dormant planet.
Similar to living beings, stars experience a life cycle. For stars with less than about 10 times the mass of the sun, the concluding phase is a White Dwarf. At this point, stars are compressed to the density of Earth and reach temperatures of around 100,000 Kelvin, approximately 100,000°C or 180,000°F. Unlike other stars, they cease to fuse elements in their cores for energy. Instead, they maintain their structure through Quantum mechanical principles and slowly release heat. This is why scientists often refer to white dwarfs as The dead star.
Nevertheless, under certain conditions, a white dwarf can experience one last surge of energy. There exists a limit to a white dwarf’s size, specifically 1.4 times the mass of the sun. If a star exceeds this threshold, gravitational forces can overpower its structural support, caused either by accumulating surrounding gas and dust or by merging with another white dwarf. This rapid compression ignites a chain reaction of fusion, culminating in an explosion known as a Type IA Supernova. Researchers estimate that such an explosion occurs in the Milky Way every 100-700 years.
A group of astrophysicists aimed to explore this phenomenon along with a rarer alternative. If a star is spinning while accumulating material, it can collapse into something even denser, a Neutron Star, and eject excess material without undergoing an explosion. The team simulated the aftermath of six different scenarios where the white dwarf collapsed after surpassing the size limit, known as Post Bounce. In these simulations, they adjusted various parameters, such as speed, width, temperature, and size thresholds of the white dwarfs.
They then controlled the initial conditions, including the mass of the white dwarf. Alkar simulated the behavior of low-energy particles referred to as liquid physics Neutrino 2D. Given the computational demands, astrophysicists typically simulate only a fraction of a second of post-bounce behavior. However, this team extended their simulation to 4.5-7 seconds to gain a deeper understanding of how ejected layers from white dwarfs behave.
The simulated white dwarf quickly collapsed, transitioning from a slower rate of 0.8 seconds to a rapid 0.04 seconds. The scenario diverged, with the unspinning white dwarf erupting into a supernova, while the spinning white dwarf transformed into a neutron star. In this latter case, the remnants of the stars were so densely packed that neutrinos collided with them, heating them up and ejecting them from the star.
The focus then shifted to the ejected material. The mass of material expelled ranged from 0.005 times to 0.05 times the mass of the sun, equivalent to about 1,700 to 17,000 Earth masses. Heavier elements like nickel can form during this process.
The researchers concluded that the outer layers ejected from collapsing white dwarfs could change rapidly during these events. They discovered that the material released was initially rich in protons and formed lighter elements but later became enriched in neutrons and heavier elements.
The team recommended developing more advanced 3D models of white dwarfs prior to their collapse for future studies. They suggested that astrophysicists could utilize these models to estimate the contribution of elements in the solar system originating from white dwarf collapses.
Fast Radio Bursts (FRBs) represent one of the greatest mysteries of the universe in our time. Initially identified in 2007, these transient radio wave phenomena have perplexed astronomers ever since.
Although we have detected thousands of them, the precise causes, origins, and unpredictable behaviors of FRBs remain elusive.
Just when scientists thought they were starting to unravel the mysteries, two new studies published in January 2025 added twists to the ongoing FRB enigma, challenging earlier theories.
“The FRB is one of those cosmic mysteries that deserves to be solved,” states Dr. Tarraneh Eftekhari, a radio astronomer at Northwestern University, in reference to the first new paper published in Astrophysics Letter.
Though the solution may be a long way off, the universe continues to guard its secrets.
What Makes the FRB Mysterious?
While it may not be entirely accurate to say that FRBs were discovered purely by chance, their initial detection happened within data collected for an entirely different purpose.
Pulsars, or “pulsating radio sources,” are far better understood cosmic phenomena, having been discovered in 1967 by Professor Jocelyn Bell Burnell, arising from neutron stars. These are incredibly dense remnants of giant stars boasting magnetic fields far stronger than Earth’s.
These rapidly spinning stellar remnants emit regular pulses of radio waves akin to cosmic beacons.
The consistency of these pulses and their emissions at specific frequencies initially led to the hypothesis that they could be of natural origin, which earned the first pulsar the nickname “Little Green Man 1.”
While pulsars quickly found their rightful place in astrophysics, FRBs tell a different story.
Jump forward to 2007 when they emerged unexpectedly from data gathered by the Parkes Multibeam Pulsar Survey, an international collaboration involving Jodrell Bank Observatory, Massachusetts Institute of Technology, Bologna Astronomical Observatory, and Australia’s National Facilities.
The emission from this event was so powerful that it overshadowed all other known sources at the time by a substantial margin.
“In terms of energy output, a 1-millisecond-long FRB can emit as much energy as the Sun produces over three days,” says Dr. Fabian Djankowski, an astrophysicist at the French National Centre for Science and Technology specializing in FRBs.
However, for over five years after the initial detection, no similar events were recorded. Skepticism faded as more FRBs began to emerge.
Thousands have been detected since then, and astronomers estimate that two or three FRBs may blaze across the sky every minute.
These enigmatic signals release immense energy from deep space, illuminating the sky with their mysterious nature. And the strangeness does not end there.
Initially, FRBs were believed to be one-off occurrences, cosmic anomalies. This assumption seemed valid, as follow-up observations failed to reveal any repeating sources.
That changed in 2016 when FRB 121102 was found to emit repeated bursts. Currently, between 3% and 10% of FRBs are classified as “repeaters.”
Why do some FRBs remain silent after a single burst, while others emit multiple bursts? This is yet another mystery awaiting resolution.
read more:
What Causes FRBs?
Numerous hypotheses have been proposed regarding the cause of FRBs, ranging from chaotic black hole collisions to extraterrestrial signals. Many explanations have emerged, including the unlikely scenario of a microwave being accidentally detected. However, one candidate seems to rise above the rest.
“When massive stars collapse and go supernova, they leave behind highly magnetized neutron stars, or ‘magnetars,'” notes Eftekhari. “The reason magnetars are a compelling candidate for FRBs is that we have observed similar events emanating from known magnetars within our Milky Way.”
Neutron stars already possess strong magnetic fields, but magnetars are in a category of their own, with magnetic fields thousands of times stronger than those of typical neutron stars.
Furthermore, a higher frequency of FRBs has been detected in galaxies with rapid star formation. As Eftekhari explains, “To produce a supernova that results in a magnetar, a massive star is required, and these giant stars are found in star-forming galaxies.”
So, is the case settled? Not quite.
The Canadian CHIME radio telescope detected FRB 20240209A, potentially originating from a globular cluster. – Photo Credit: CHIME Experiment
This is where the two new studies published in January 2025 come into play, both examining the recurring FRB known as 20240209A.
“The first exciting aspect of this FRB is that it originates outside our galaxy,” says Vishwangi Shah, a doctoral student at McGill University, referencing the second study.
“There is only one other FRB detected outside our galaxy. In terms of its repeaters, I believe it originates from a globular cluster.”
Both Eftekhari and Shah suggest that 20240209A is also associated with globular clusters (dense groups of ancient stars existing on the outskirts of galaxies).
“This is remarkable,” Eftekhari comments. “The notion of magnetar progenitors poses a challenge since they typically require a group of young stars to form magnetars.”
So what does this mean for FRBs? One possibility is that magnetars are still the culprits, but they may be generated through entirely different mechanisms.
For instance, within these stellar graveyards, two normal neutron stars might combine to form magnetars. Alternatively, a white dwarf—a stellar remnant too small to evolve into a neutron star—could gather material from a nearby companion, culminating in a massive explosion that results in a magnetar.
Ultimately, the exact origin of these outlier events remains unknown. “It’s thrilling to contemplate that we might be dealing with a subpopulation of FRBs,” Eftekhari remarks. “This case isn’t as clear as it appears.”
Can We Determine the Origins of FRBs?
Despite nearly two decades of research, many questions regarding FRBs linger. Which objects are responsible? What processes drive these phenomena? And why do some FRBs repeat while others do not?
Thanks to advances in FRB detection technology, answers may be nearer than anticipated.
CHIME is currently undergoing enhancements aimed at pinpointing bursts with unprecedented precision.
This advancement in FRB detection represents great progress in unraveling their mysteries. While many FRBs have been observed, accurately identifying their environments has left several key questions regarding their origins unanswered.
Jankowski believes that in the near future, many cases like 20240209A could be unlocked, revealing their underlying mechanisms. “I anticipate significant progress in the coming years,” he adds.
The Square Kilometer Array (SKA), a massive observatory spanning Australia and South Africa, aims to join the search for FRBs shortly.
Eftekhari and Shah have also proposed utilizing the James Webb Space Telescope to explore the region where 20240209A was detected.
“It’s an incredibly exciting time for FRB research,” highlights Jankowski. “We are poised to make remarkable discoveries in the next few years.”
Meet Our Experts
Dr. Tarraneh Eftekhari is a radio astronomer at Northwestern University, USA, with contributions to various scientific journals including Astrophysics Letter, Nature Astronomy, and Astrophysical Journal.
Dr. Fabian Djankowski is an astrophysicist at the French National Centre for Science and Technology who specializes in FRBs. His work has appeared in Monthly Notices of the Royal Astronomical Society, Astrophysics Letter, and Astronomy and Astrophysics.
Vishwangi Shah is a doctoral student at McGill University in the USA and a researcher focusing on radio astronomy and FRBs. She has been published in Astrophysics Letter and Astronomy Journal.
Similar to childbirth, the process of dying involves stages and noticeable progressions. The speed at which this process occurs varies from person to person, just like in childbirth. In some cases, medical support may be necessary to ensure that dying, or childbirth, is as safe and comfortable as possible.
As death nears, most individuals lose interest in eating and drinking. This is a normal occurrence, and sometimes only a small amount of food may be welcomed when regular meals become overwhelming.
Dying individuals often experience extreme fatigue due to a lack of energy. While sleep usually helps to replenish energy and aid in recovery, in the final stages of life, the impact of sleep diminishes as the body weakens towards death.
Individuals approaching death spend less time awake and more time in a state of apparent unconsciousness. When they do wake up, many report feeling as though they had peacefully slept without any sense of being unconscious.
If the dying person relies on regular medications to manage symptoms, it is important to transition to medications that can be administered without the person needing to be awake. Skin patches, syringe pumps, or suppositories can be considered. It’s crucial to note that loss of consciousness is typically a result of the dying process itself rather than the medication.
What happens in the final moments?
As death progresses, heart rate decreases, blood pressure drops, skin temperature decreases, and fingernails darken. Internal organs also slow down as blood pressure declines. Restlessness, confusion, and periods of deepening consciousness may occur during this time.
While there are no established methods for studying the experiences of dying individuals, recent studies suggest that the unconscious brain may respond to noise as death approaches. Breathing patterns in an unconscious person are governed by the brain stem’s respiratory center, leading to heavy breathing and occasional saliva flow.
Breathing patterns may shift from deep to shallow and fast to slow until breathing eventually slows, becomes shallow, pauses, and ceases altogether. Following a few minutes without oxygen, the heart stops beating.
Recognizing common patterns of dying and understanding its stages can help companions comprehend what is happening, alleviate fears of unlikely complications, and empower them to seek medical assistance if necessary to manage symptoms and ensure a peaceful passing. Additional information can be found in BBC Short Films on Death.
Similar to childbirth, death is a bodily process that progresses through stages and is recognizable. The speed of the process varies from person to person, and medical support may be necessary to ensure a safe and comfortable experience.
As death nears, most people lose interest in eating and drinking, which is normal. Even if they are unable to manage full meals, a small taste may still be welcomed.
Dying individuals typically experience a lack of energy, similar to the extreme fatigue associated with severe illness or surgery recovery. While sleep normally recharges energy, it gradually diminishes as the body weakens towards death.
Waking hours decrease, and periods of unconsciousness become more frequent. People report feeling like they were peacefully asleep during these periods of unconsciousness.
If the dying person relies on regular medications, it may be necessary to switch to medications that do not require swallowing. Skin patches, syringe pumps, and suppositories can be used, as unconsciousness is usually caused by the dying process, not medication.
What happens in your last moments
As death progresses, the heartbeat slows, blood pressure drops, the skin cools, and the nails dull. Restlessness, confusion, and periods of deepening unconsciousness may occur.
There is no proven method to investigate what people experience near death, but recent research suggests that the unconscious brain responds to noise in the room. Breathing becomes automatic and may involve heavy, noisy breaths or breathing through saliva in the back of the throat without signs of distress.
Breathing cycles from deep to shallow, fast to slow, until it becomes slow and very shallow, eventually pausing and stopping altogether due to lack of oxygen.
Understanding common patterns of death and its stages can help companions feel less fearful and manage symptoms. Seeking medical attention when necessary is important. For more information, you can watch the BBC short film about death: BBC short film about death.
This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
