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New Gravity Theory Suggests How Cosmic Order Emerges Despite Rising Entropy

23 July 2026 at 13:41

Galaxies, stars, and living cells are all examples of local order emerging in the universe. At first glance, that seems to contradict one of physics’ oldest principles.

However, a recent study in Physical Review D offers a mathematical explanation for how these structures form while still obeying the second law of thermodynamics.

The second law of thermodynamics states that entropy, or disorder, in an isolated system always increases over time. Einstein famously said that “the second law of thermodynamics occupies a unique position among the laws of Nature,” reflecting how fundamental he believed the principle to be.

In its early days, the universe was smooth and uniform, with low entropy. As it expanded, gravity pulled gas into stars, stars into galaxies, and eventually made life possible. Each step seems to create order in one place, even though the universe as a whole became more disordered. Cosmologists have usually explained this by pointing to the universe’s growing volume.

Gravity as a Ledger, Not a Force

Mathematician Ginestra Bianconi at Queen Mary University of London addressed this problem with a framework called Gravity from Entropy. Rather than treating gravity as a fundamental force, the Gravity from Entropy framework proposes that it emerges from an information-based difference between two descriptions of spacetime geometry. One metric describes the actual shape of spacetime, while the other describes the geometry that matter and curvature would create. When these two match, gravity disappears. When they differ, gravity arises from the difference.

In the low-energy, weak-curvature limit, the framework reduces to general relativity. In the new study, Bianconi adds a thermodynamic perspective. She applies Gravity from Entropy to the standard model of an expanding universe and shows that the local geometric degrees of freedom follow the first law of thermodynamics, with their own temperature and pressure emerging from the equations.

Falling Density, Rising Total

One of the study’s central findings is the distinction between total entropy and entropy per unit volume. As the universe grows, the total entropy increases, just as the second law demands. However, the study found that entropy per unit volume decreases over time even as the universe’s total entropy continues to increase. Within the Gravity from Entropy framework, Bianconi proposes that this declining local entropy density may help explain how galaxies and other cosmic structures emerge.

The study also shows that these geometric temperatures change depending on what dominates the universe. In a universe dominated by matter or radiation, the temperature decreases over time. In a universe dominated by dark energy, like our own, they remain nearly constant. The framework even assigns a temperature and pressure to empty spacetime.

A Theory Still Waiting to Be Tested

“This work reveals how the Gravity from Entropy theory can tackle the challenging question of reconciling the second law of thermodynamics with the emergence of complexity in our universe,” stated Bianconi. “These results may open new avenues for investigating the long-standing problem of reconciling the foundations of cosmological irreversibility, the emergence of complex structures, and ultimately life with fundamental gravitational dynamics.”

So far, Gravity from Entropy has not been confirmed by observations. The theory makes predictions that future observations of large-scale cosmic structures and other gravitational phenomena could test. While it remains unproven, Bianconi believes it could offer a new way to link gravity, thermodynamics, quantum mechanics, and the rise of complexity in the universe.

Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.

The Sun’s twin star may have tilted the planets’ orbits

23 July 2026 at 12:00

Around 4.6 billion years ago, an immense cloud of gas and dust in space collapsed in on itself. As it collapsed, gravity pulled most of the material toward several small points, one of which would eventually become our Sun. The other points formed other stars in what scientists call an open cluster. 

During this early stage of the Sun’s life, it was surrounded by a swirling disk of leftover material aligned with its equator, known as a protoplanetary disk. Eventually, this disk condensed to form the planets that make up our solar system. This process normally results in a system with a star at its center, and the planets orbiting the plane of the star’s equator. 

However, scientists have found that this scenario doesn’t quite hold for our solar system. The planets in our solar system orbit the Sun in a single plane offset from the Sun’s equator by approximately 6°. The fact that the planets are in the same orbital plane suggests that the protoplanetary disk model of solar system formation is correct, since the odds of the Sun capturing 8 rogue planets in this arrangement are astronomically low. So, what threw the planets in our solar system off-kilter?

The plane in which the solar system’s planets orbit the Sun is offset from the Sun’s equator by approximately 6°. Li simulated how the solar system tilted based on its 4 largest planets, from left to right: Neptune, Saturn, Jupiter, and Uranus.

The plane in which the solar system’s planets orbit the Sun is offset from the Sun’s equator by approximately 6°. Li simulated how the solar system tilted based on its 4 largest planets, from left to right: Neptune, Saturn, Jupiter, and Uranus. Illustration by Andrew Bizal.

To determine what caused the solar system to tilt, Daohai Li at Queen Mary University of London recently used the computer program NBODY6++ to model different versions of the open cluster from which the Sun came. In these simulations, he varied the number of stars in the cluster, from 500 to 2,000 to 8,000. He also varied the radius of the cluster, from 0.25 to 1 to 4 parsecs (8 to 30 to 100 trillion kilometers or 5 to 20 to 70 trillion miles). Finally, he varied the percentage of stars with a binary companion from 10% to 50% to 90%. Li assigned each star a randomly generated initial mass, starting position, and velocity, and simulated their interactions for 400 million years.

First, Li examined the simulations to identify stars with masses approximately equal to the Sun’s. From this group of solar-massed stars, Li found ones that left the cluster after 400 million years as a single star, after either forming alone or having lost a former companion star. He proposed that these stars were the most similar to the Sun and could thus host a simulated solar system.

Li then simulated the planets and their orbits as they would have formed on these potential host stars. To simplify this process, Li only simulated the 4 giant planets, Jupiter, Saturn, Uranus, and Neptune, which dominate planetary behavior in our solar system. He modeled these solar systems independently for 200 million years to ensure they would remain intact and used those that did for statistical analysis of the solar system’s past.

Overall, Li discovered 2 scenarios that could explain the solar system’s tilt. In the first, the primordial solar system was jostled by many distant neighboring stars in its cluster. This jostling tilts the planets’ orbits, but it does so randomly. Therefore, this scenario would make it unlikely for the planets to remain in the same orbital plane. It would also cause them to orbit the Sun faster and more chaotically than in our solar system.

In the second scenario, the Sun had a temporary companion star that it either formed with or briefly encountered before separating. When this occurred, the simulated planets’ orbits all tilted together. Stars that formed with a binary companion had a 10% chance of tilting their planets’ orbits by 6° or more, while stars that formed alone had a less than 0.1% chance. 

Li concluded that the solar system could have tilted as a result of interactions between the Sun and a temporary companion star within its parent cluster. However, he acknowledged that the model strongly depends on how closely a star passes by the Sun, since the closer a star passes, the more it disturbs the solar system. Despite this uncertainty, it’s possible that somewhere in space is the Sun’s twin or former neighbor that we haven’t seen in eons, and that’s what made our solar system crooked!

The post The Sun’s twin star may have tilted the planets’ orbits appeared first on Sciworthy.

Scientists may have found the 1st twin star system where both stars exploded

For the first time, scientists may have discovered a binary system—like the twin suns of the fictional planet Tatooine in "Star Wars"—where both stars exploded as supernovas, a new study finds.

Although Earth may orbit around a single star, more than half of all stars are in systems where two or more suns orbit each other. "When it comes to massive stars, the percentage in multiple systems are even higher," study lead author Miltiadis Michailidis, a postdoctoral fellow at Stanford University in California, told Space.com.

When massive stars burn all their fuel, they can die in giant explosions known as supernovas. These outbursts can briefly outshine all of the other suns in these stars' galaxies. They often leave behind expanding super-hot clouds of debris known as supernova remnants. Astronomers have detected about 300 such remnants in our galaxy to date.

Given how often massive stars are found in binary systems, "one can expect many pairs of massive stars where both will explode as supernovas," Michailidis noted. "However, this has never been observed, until now."

One reason supernova pairs may have escaped attention is that "if the stars are too close together when they exploded, the resulting supernova remnants may look like that from a single explosion," Michailidis explained. Another is that one star going supernova may propel its partner far enough away to hide the fact they were ever a duo, he added.

In the new study, Michailidis and his colleagues investigated a supernova remnant known as IC 443, located about 6,000 light-years from Earth in the constellation Gemini. IC 443 is also known as the Jellyfish Nebula for how it resembles a jellyfish.

IC 443 is one of the most extensively studied supernova remnants in the galaxy because of how shock waves from the supernova have collided with surrounding clouds of gas and dust to create a set of concentric bubble shells, "much like how a drop of water falling on a lake creates circular waves," Michailidis said. "It is very isolated from its surroundings, without many other objects nearby to complicate its very bright emissions."

The scientists analyzed one of IC 443's much dimmer, long-hidden neighbors, dubbed G189.6+3.3. The German-led ROSAT (Roentgen Satellite) mission first discovered G189.6+3.3 in 1994 via its faint X-ray emissions, and the Russian-German Spektrum Roentgen Gamma (SRG) space observatory later clearly detected shell-like structures within G189.6+3.3, suggesting that it was a supernova remnant.

A pink haze over the jellyfish nebula.

A composite multiwavelength view of the IC 443 region (with the X-ray emission from IC 443 removed) overlaid with gamma-ray emission above 1 GeV detected by the Fermi Large Area Telescope.  (Image credit: NASA Goddard Space Flight Center and M. Michailidis et al. 2026; orange, brown: radio, ESA/Planck and MWISP; yellow: optical, DSS; red: infrared, NASA/WISE; violet: ultraviolet, NASA/Swift; teal: X-rays, SRG/eROSITA; magenta: gamma rays, NASA/DOE/Fermi LAT Collaboration)

In the new study, the researchers analyzed more than 16 years of data from NASA's Fermi Gamma-ray Space Telescope along with earlier X-ray, optical and radio measurements. They discovered signs that both IC 443 and G189.6+3.3 were both smashing into the same interstellar cloud of hydrogen, revealing they were close together in space, with the centers of their explosions about 30 to 50 light-years apart.

The researchers calculated that the chances of randomly encountering two unrelated supernova remnants at this distance from one another "was about one in 1,000," Michailidis said. "This suggests that our discovery is in fact the first known binary-system supernova pair."

The scientists estimated that G189.6+3.3 was older than IC 443, with the parent star of G189.6+3.3 exploding between 20,000 to 110,000 years ago, while IC 443 was created about 8,000 to 9,000 years ago. The original stars may have been 20 or more times the sun's mass.

These new findings can help shed light on how massive binary stars evolve, interact and die. For instance, further analysis of G189.6+3.3 and IC 443 can reveal how much of a kick the former gave the latter when it died, Michailidis said.

The scientists detailed their findings July 21 in the journal Nature Communications.

Apple TV adaptará “Peculiar Stars”, futuro romance de Rebecca Yarros

22 July 2026 at 18:41

O Apple TV adquiriu antecipadamente os direitos de produção de “Peculiar Stars”, o vindouro (e bastante disputado) romance de Rebecca Yarros, autora conhecida pela série de livros “Empyrean”.

A aquisição foi confirmada pelo serviço no X. A série será produzida pelo Apple Studios e contará com Yarros como produtora executiva, por meio da sua empresa Full Measures Productions.

A new tale of survival and romance from bestselling author Rebecca Yarros.

Apple Studios will develop Peculiar Stars, and Yarros will serve as executive producer through her banner Full Measures Productions. pic.twitter.com/g2KTQ6ZnSL

— Apple TV (@AppleTV) July 22, 2026
Uma nova história de sobrevivência e romance da autora best-seller Rebecca Yarros.

O Apple Studios desenvolverá “Peculiar Stars”, e Yarros será produtora executiva por meio da sua produtora, a Full Measures Productions.

“Peculiar Stars” será publicado em novembro e acompanhará uma jovem que fica presa em uma ilha deserta com um membro da família do seu noivo — o que transformará sua visão sobre o amor.

Quando eles são finalmente resgatados e retornam aos seus mundos repletos de privilégios, expectativas e segredos, esse retorno se mostra muito mais perigoso do que a ilha onde estavam.

De acordo com o Deadline, a Apple ainda está à procura de um roteirista para escrever a adaptação. No livro, a história terá um ritmo lento, se desenrolando por 543 dias na ilha supracitada.

O Apple TV está disponível no aplicativo Apple TV em mais de 100 países e regiões, seja em iPhones, iPads, Apple TVs, Macs, dispositivos Android, smart TVs ou online — além de também estar em aparelhos como Roku, Amazon Fire TV, Chromecast com Google TV, consoles PlayStation e Xbox. O serviço custa R$29,90 por mês, com um período de teste gratuito de 7 dias. Por tempo limitado, quem comprar e ativar um novo iPhone, iPad, Apple TV ou Mac ganha 3 meses do Apple TV. Ele também faz parte do pacote de assinaturas da empresa, o Apple One.

NOTA DE TRANSPARÊNCIA: O MacMagazine recebe uma pequena comissão sobre vendas concluídas por meio de links deste post, mas você, como consumidor, não paga nada mais pelos produtos/serviços usando os nossos links de afiliado.

'The Starry Night' in space: Dark Energy Camera channels a cosmic Van Gogh (video)

17 July 2026 at 16:00

Reboots and remakes may be all the rage in Hollywood with mixed degrees of success (we don't talk about the Nightmare on Elm Street reboot ... ever), but they aren't so popular in other forms of art such as painting. However, a recent cosmic rework of one of art's most well-regarded pieces could be just as breathtaking as its original counterpart.

That's all thanks to the Dark Energy Camera (DECam), which has captured a vibrant view of the Corona Australis molecular cloud, that shows the star-forming region resembling a cosmic take on Vincent Van Gogh's iconic painting The Starry Night.

The Corona Australis Molecular Cloud measures around 16 light-years in diameter is located around 430 light-years from Earth, making it one of the closest star-birthing regions to our solar system. The molecular cloud and its dark lanes of gas and dust, the raw materials for star construction, are at the left of the DECam image.

A vibrant view of the Corona Australis Molecular Cloud as seen by the DECam painting a scene reminiscent of Van Gogh’s The Starry Night.

A vibrant view of the Corona Australis Molecular Cloud as seen by the DECam painting a scene reminiscent of Van Gogh’s The Starry Night. (Image credit: Dark Energy Survey/DOE/FNAL/DECam/ CTIO/NOIRLab/NSF/AURA)

Also prominent on the left of the image is the shining nebula NGC 6729, which is a reflection nebula of the Corona Australis Molecular Cloud. That means that it is a cloud of interstellar dust that is reflecting the light of the newborn stars embedded within this molecular cloud.

NGC 6729 is composed of different elements that can be seen on the left side of the image. This includes an orange cloud that is actually the binary star system R Coronae Australis. This binary consists of a pre-main-sequence star that has gathered mass but hasn't yet triggered the fusion of hydrogen to helium in its core, and its companion, a red dwarf star. These stars orbit each other every 43 to 47 years and are incredibly bright, with their light also reflecting from nearby reflection nebulas. This light also ionizes nearby gas, creating glowing regions called emission nebulae, also part of NGC 6729.

clouds of multicolored gasses on a starry background

At left, the young binary system R Coronae Australis illuminates surrounding gas and dust, while the glittering globular cluster NGC 6723 shines at upper right, far beyond the nearby stellar nursery. (Image credit: Dark Energy Survey/ DOE/ FNAL/ DECam/ CTIO/NOIRLab/NSF/AURA)

To the top-right of the image is the globular cluster NGC 6723, nicknamed the Chandelier Cluster. Located around 29,000 light-years from Earth, NGC 6723 is thought to contain some of the oldest stars in the Milky Way.

The Chandelier Cluster contains tens of thousands to millions of stars, which aren't all ancient; within the spherically shaped globular cluster are more than a smattering of younger stars.

Astronomers and astrophotographers of all levels will be more than familiar with the Corona Australis Molecular Cloud and the Chandelier Cluster and this region as a whole.

But just as it took the artistic vision of Van Gogh to transform the night sky into a stunning painting, it has taken the observing power of the DECam, mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile, to bring out the stunning beauty of this slice of the night sky.

July 16, 1850: Bond and Whipple photograph Vega

16 July 2026 at 14:00

In 1839, the president of Harvard University invited William Bond to move into a house on campus and, by virtue of bringing along his own astronomical equipment, become the university’s first astronomer in residence. With public interest spurred by the 1835 passage of Halley’s Comet and the Comet of 1843, Harvard soon had enough moneyContinue reading "July 16, 1850: Bond and Whipple photograph Vega"

The post July 16, 1850: Bond and Whipple photograph Vega appeared first on Astronomy Magazine.

Scientists spot 4 superdense stellar corpses hiding behind their red dwarf companions

14 July 2026 at 22:00

Astronomers have spotted four dead star white dwarf stars playing a game of cosmic hide-and-seek, all four of which were hiding in the glares of red dwarf companion stars.

This marks the first detection of white dwarfs existing in double star systems in our cosmic backyard. The white dwarfs are all located within around 65 light-years of Earth, and one of them is number nine in the top 10 closest white dwarfs to the solar system.

White dwarfs are the type of stellar remnants left behind when stars around the size of the sun run out of fuel needed for nuclear fusion. This leads to their cores collapsing. The lack of fusion also means these stellar remnants cool and become dim. Thus, the light of much larger and brighter red dwarf stars is incredibly effective at hiding white dwarfs.

"Nearby isolated white dwarfs are usually easy to find, but we couldn't see these four stars directly in visible wavelengths because their red dwarf companions were drowning out their light," team leader Mairi O'Brien of the University of Warwick in the UK said in a statement. "It's a reminder that even in our own cosmic neighborhood, we can still find surprises if we look in the right way, at the right wavelengths."

Wobbles gave them away

Though astronomers have been diligently surveying our cosmic backyard for decades, white dwarfs are extremely good at remaining unseen. In fact, the only thing that gave these four hidden dead stars away? Curious "wobbles" caused in the motion of the stars they were hiding behind, like a hiding child causing a curtain to ripple.

The team followed up on these telltale clues by taking a closer look at these systems with NASA's long-serving Hubble Space Telescope. This investigation was conducted in ultraviolet light and using custom calibration to prevent flaring from the red dwarf companions from mimicking white dwarf signals.

This investigation not only revealed the four lurking white dwarfs, but also demonstrated that one of these systems, G 203-47, located just 25 light-years away, has some curious characteristics. Twenty-seven years elapsed between the initial radial wobble and the detection of this hidden dead star.

That isn't the weird thing, though. What is strange is that the red dwarf companion of this white dwarf only rotates once every 100 Earth days or so, yet it only takes about 15 days to orbit its dead star companion. This means that gravitational forces have failed to lock the red dwarf and white dwarf together, which is what happens in similar systems.

"What's fascinating is that G 203-47 shouldn't be rotating this slowly if it formed the same way as similar systems. This suggests that these binaries have had very different evolutionary histories," team member David Wilson, of the University of Colorado Boulder, said. "Some underwent violent, prolonged interactions early on that locked them tidally. Others, like G 203-47, experienced gentler, briefer encounters that left them in this unusual state."

An illustration of a reddish white star in the foreground and a blue star in the background.

An illustration of a red dwarf star orbiting a white dwarf dead star companion. (Image credit: Robert Lea (created with Canva))

The discovery of these white dwarfs helps researchers better understand the population numbers of the dead stars throughout the Milky Way. In fact, predictions would have suggested finding roughly four to five closely orbiting white dwarf-red dwarf pairs within around 65 light-years of our solar system, so finding four should instill a lot of confidence in our current theoretical models.

"Only about 30% of red dwarfs within 20 parsecs [65 light-years] have been systematically surveyed for hidden white dwarf companions," team member and University of Warwick researcher Pier-Emmanuel Tremblay said in the statement. "We think there could be as many as nine or 10 additional binary systems in our local stellar environment that we haven’t found yet.

"If we put more targeted effort into observing red dwarfs, perhaps we will find more surprises like this."

The team's research was published on Tues (July 14) in the journal Monthly Notices of the Royal Astronomical Society (MNRAS).

This cosmic 'lighthouse' is blazing a magnetic trail through the Milky Way

14 July 2026 at 17:00

Astronomers have, for the first time, directly mapped the magnetic field surrounding an unusual "lighthouse" pulsar, revealing an invisible cosmic highway that channels particles blasted from the rapidly spinning stellar remnant.

Using NASA's Imaging X-ray Polarimetry Explorer (IXPE) mission, researchers measured the magnetic field around the pulsar PSR J1101−6101 — nicknamed the "Lighthouse" — and confirmed a long-standing prediction that its high-energy particles stream along magnetic field lines extending through the Milky Way. This discovery offers a rare look at how some of the universe's most extreme objects accelerate particles to nearly the speed of light, according to a statement from the space agency.

Pulsars are rapidly rotating neutron stars — the ultra-dense remnants left behind when massive stars explode as supernovas. Their powerful magnetic fields channel beams of radiation from their magnetic poles that sweep across space as the stars spin, much like the beam of a lighthouse.

PSR J1101−6101, which is located at the center of the Lighthouse Nebula, spins about 16 times every second and is traveling at supersonic speeds after receiving a powerful kick from the supernova that created it. As it tears through interstellar gas, it leaves behind a bright X-ray tail while producing a narrow filament that juts out almost perpendicular to its direction of travel. Astronomers had long suspected this unusual structure traced energetic electrons escaping along the Milky Way's magnetic field.

"We wanted to test that theory,"Jack Dinsmore, lead author of the study and undergraduate student at Stanford University, said in the statement. "The 'smoking gun' would come by measuring the polarization of the light, which indicates the magnetic field direction. If the magnetic field points along the filament, that confirms that the filament's particles are flowing along the field."

Unlike conventional X-ray telescopes, IXPE measures the polarization of X-rays — the preferred orientation of their electric fields — allowing scientists to reconstruct the geometry of otherwise invisible magnetic fields. Because the Lighthouse Nebula is relatively faint in X-rays, the researchers developed new analysis techniques to extract as much information as possible from the observations.

A full view of the composite IXPE helped construct. There's a purple version of the blue streak in IXPE's boxout that very much resembles the blue streak.

Using IXPE, astronomers measured the nebula's magnetic field for the first time, confirming that high-energy particles escape the pulsar by traveling along the Milky Way's magnetic field lines. (Image credit: X-ray: Chandra: NASA/CXC/Stanford Univ./J.T. Dinsmore et al.; IXPE: NASA/MSFC/J.T. Dinsmore et al., Radio: CSIRO/ATNF/ATCA; Optical: 2MASS/UMass/IPAC-Caltech/NASA/NSF; Image processing: NASA/CXC/SAO/L. Frattare)

The team found that the magnetic field runs parallel to a remarkably long filament extending away from the pulsar, confirming that high-energy particles are streaming along magnetic field lines. But the observations also uncovered an unexpected twist: the field is far more orderly than scientists anticipated. The unusually strong polarization signal suggests the filament contains much less magnetic turbulence than current models predict, offering new insight into how fast-moving pulsars inject energetic particles into the surrounding galaxy.

"The striking divergence in magnetic field orientations observed between radio and X-ray wavelengths provides compelling evidence for the highly structured nature of these objects," Niccolò Bucciantini, co-author of the study from the Italian National Institute for Astrophysics, said in the statement. "This marks the first clear indication that particles of different energies occupy distinct regions within the system, hinting at the presence of multiple, and potentially very different, acceleration mechanisms at work."

Their findings were published July 9 in The Astrophysical Journal.

Astronomers may have heard the 1st 'whispers' of ghost particles created by supernova explosions

10 July 2026 at 11:00

The universe is haunted by "cosmic ghosts" called neutrinos, and new research suggests they may be the "whispers" of stars that died in supernova explosions over the course of billions of years.

The discovery is an important step forward in our understanding of the life and death of stars and how they enrich their environments with metals, elements heavier than hydrogen and helium. It could also help better understand how black holes and neutron stars are born when massive stars die.

The second most common particles in the universe, neutrinos get their spooky nickname because they are chargeless and near-massless, so phantom-like that around 100 trillion neutrinos pass through you at nearly the speed of light every second, but over your entire life only one will interact with the atoms of your body, if you're lucky.

The newly suggested connection between neutrinos and a history of supernova blasts has emerged from the first detection of a flux of neutrinos called the Diffuse Supernova Neutrino Background (DSNB). It was detected by one of the world's largest neutrino detectors, the Super-Kamiokande, located 3,280 feet (1,000 meters) underground in Gifu Prefecture, Japan.

"Observing the world's first indication of the Diffuse Supernova Neutrino Background is a deeply meaningful achievement and has been a long-cherished goal since the beginning of the Super-Kamiokande project," Hiroyuki Sekiya of the University of Tokyo said in a statement.

Stars go out with a bang but continue with a whisper

Supernovas come in a range of types, but the ones this research concerns are so-called "core-collapse supernovas." These occur when stars much more massive than the sun reach the end of nucleosynthesis in their cores. When they are no longer able to fuse elements to create metals heavier than iron, the stars become unable to produce the outward energy that for millions of years has balanced them against the inward push of gravity.

Thus, with gravity the ultimate winner of this cosmic tug of war, the star's core collapses, sending violent shockwaves rippling outward into the outer stellar layers, which are ripped away. This leaves the core as a stellar remnant, either a neutron star or a black hole, initially surrounded by an expanding shell of supernova debris.

The energy from these events is carried away by particles of light (photons) spread across the electromagnetic spectrum, but also by neutrinos. Yet, despite the fact that supernovas have been erupting every second over the course of 13 billion years or so to produce the neutrinos that accumulate as the DSNB, this ghostly signal is still faint, a whisper rather than a shout.

The Crab Nebula as seen by the Hubble Space Telescope and ground-based telescopes in a composite view The nebula is the aftermath of a brilliant supernova spotted in 1054.

The Crab Nebula as seen by the Hubble Space Telescope and ground-based telescopes in a composite view The nebula is the aftermath of a core-collapse supernova. (Image credit: NASA, ESA, NRAO/AUI/NSF and G. Dubner (University of Buenos Aires))

To "hear" these cosmic whispers, the team behind this research analysed almost 14 years of data from Super-Kamiokande in the form of Cherenkov light generated when neutrinos interact with 50,000 tons of ultrapure water.

This revealed a signal of neutrinos in line with what would be expected from the DSNB. This signal still needs to be confirmed, but it is a strong indicator of the DSNB, the first humanity has ever had.

Since the birth of the universe, neutrinos emitted by supernovas have diffused through space and accumulated over cosmic time.

Across the universe, supernova explosions occur several times per second. Since the birth of the universe, neutrinos emitted by these supernovae have diffused through space and accumulated over cosmic time. (Image credit: Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo)

"We are already planning on incorporating ongoing observations at Super-Kamiokande together with its successor detector, Hyper-Kamiokande, to further improve sensitivity in future collaborative studies," said team member Yosuke Ashida,of Tohoku University.

The team's results were presented on June 25, 2026, at Neutrino 2026: XXXII International Conference on Neutrino Physics and Astrophysics, held at the University of California, Irvine, USA.

This ball of stars named Terzan 5 may be one of the Milky Way's original building blocks

22 June 2026 at 22:00

A huge, shining bauble of stars called Terzan 5 could be a clump of our galaxy's central bulge that hasn't been smoothed out into the mix, and has instead survived as a fossil relic leftover from the birth of the Milky Way galaxy.

"Terzan 5 may provide direct evidence that can help explain how bulges formed in galaxies throughout the universe," said Barbara Lanzoni of the University of Bologna in a statement. Lanzoni is a member of a team of astronomers, led by Bologna colleagues Giorgia Zullo and Francesco Ferraro, who tackled Terzan 5 with the James Webb Space Telescope (JWST).

Terzan 5 is a globular cluster — a huge sphere of stars with a total mass two million times greater than our sun's and a total luminosity 800,000 times greater. The problem is, Terzan 5 lies about 18,800 light-years away in the bulge of the Milky Way galaxy. This means dense lanes of intervening galactic dust block our view, significantly dimming Terzan 5's apparent brightness. That's why it wasn't discovered until 1968 by the Turkish–French–Armenian astronomer Agop Terzan.

Globular clusters tend to be ancient. They also tend to have formed all their stars in one giant burst. As such, all their stars should be the same age, 12 to 13 billion years old. Yet, a select few globular clusters show evidence of having more than one generation of stars. These include Omega Centauri, NGC 2808 and NGC 1783 in the Milky Way galaxy, as well as NGC 411 in the Small Magellanic Cloud and NGC 1696 in the Large Magellanic Cloud. Several explanations have been put forward, including the possibility that they are the core remnants of dwarf galaxies that have been stripped of most of their stars by gravitational tidal forces emanating from the Milky Way. Or perhaps these clusters were simply massive enough to retain some molecular gas for future stellar generations.

When the Hubble Space Telescope took a look at Terzan 5 in 2009 and then again in 2016, it found that it too was among the ranks of weird globular clusters with two generations of stars, dating back 12.5 and 4.7 billion years. However, because it is behind so much galactic dust, not even Hubble has the clearest of views.

The JWST, however, does. Its near-infrared vision can see through the dust.

"Webb's new near-infrared observations, cross-referenced with Hubble's archival observations, have given us a much clearer picture of the history of Terzan 5," said study leader Giorgia Zullo, who is a Ph.D. student at Bologna.

The JWST detected two further generations of stars, one generation born 3.8 billion years ago and another 2.5 billion years ago. Four generations of stars is hard to explain for any globular cluster, which is why the team think that Terzan 5 could be something more primordial: a leftover building block of the Milky Way's bulge that was never quite assimilated by our galaxy.

"For some reason, this peculiar clump of stars formed separately from the bulge and was not destroyed as the bulge itself formed," said Ferraro. "Terzan 5 is what we now call a bulge fossil fragment because it resembles the primordial clumps that contributed to the formation of the bulge."

Disk galaxies sport two main components: a relatively narrow disk formed from spiral arms, and a bulbous core called the bulge. Galactic bulges tend to be the oldest parts of galaxies, forming billions of years before the disks, at least in the Milky Way's case. The JWST is seeing this process occurring in the early universe, revealing clumpy, young galaxies, but given the great expanse of space and time that JWST is looking across, the observations of the building blocks that go into making these galaxies are still not totally clear. With Terzan 5, we could be looking at one of the building blocks of the Milky Way's bulge relatively close-up, and it could provide new insights into the birth of our galaxy.

An artist's impression of the James Webb Space Telescope flying through space against a star strewn deep blue sky featuring nebula clouds.

An artist's impression of the James Webb Space Telescope. (Image credit: NASA, ESA, CSA, Northrop Grumman)

Terzan 5 is probably not the only bulge fossil fragment either. As well as those other aforementioned globular clusters, some of which might be fossil fragments and others might be the cores of dwarf galaxies, the globular cluster Liller 1 close to the center of our galaxy shares many of Terzan 5's properties, including its high abundance of heavy elements produced by multiple generations of stars that have died either in supernova explosions.

The team are now looking to chase up another 40 or 50 globular clusters in the bulge to see if they could also be bulge fossil fragments, or whether they are just regular globular clusters.

The findings were presented at the 248th meeting of the American Astronomical Society in Pasadena, California which took place between June 14 and June 18. A paper describing the JWST observations has also been published in the journal Astronomy & Astrophysics.

Our sun is destined to 'kick and spit' its way across the solar system when it dies

22 June 2026 at 15:00

Scientists have discovered that dying stars don't go down without a fight. New research suggests that when stars like the sun enter their red giant phase, they spit out blobs of plasma and receive a corresponding "kick" in the opposite direction.

Stars become red giants when the hydrogen in their cores is exhausted, and that core collapses. This results in the outer layers of the star where nuclear fusion is still occurring, puffing out and expanding the star's radius to as much as 100 times its original size. Those outer layers are eventually lost altogether, leaving behind a dense stellar remnant known as a white dwarf. The sun itself will undergo this transformation in around 5 billion years, swelling out to around the orbit of Mars and engulfing the inner rocky planets, including Earth.

California Institute of Technology researcher Jim Fuller calculated that before a star becomes a white dwarf, it will receive around 10,000 little kicks over the course of hundreds of thousands of years. The cause of these kicks is the ejection of blobs of plasma from the red giant stars.

"In this model, blobs of matter are chaotically being ejected from the surface of the bloated stars in an asymmetric fashion," Fuller said in a statement. "And every time that happens, the star gets a little kick in the opposite direction. Like Newton said, for every action there is an equal and opposite reaction."

The blobs of plasma will be chaotically ejected in random directions, but this will still result in an overall net push on the red giant, a phenomenon mathematicians call a "random walk." This is akin to randomly flipping a coin to decide whether to move north or south and still eventually finding yourself moved from your starting position.

Fuller determined that for a red giant, this random walk would see a movement in a random direction at a speed of around 2,200 mph (3,540 km/h). This may seem like a lot, but it pales in comparison to the kicks received by massive stars that explode as supernovas.

An illustration shows a red giant ejecting plasma and receiving a kick in the opposite direction

An illustration shows a red giant ejecting plasma and receiving a kick in the opposite direction (Image credit: Jim Fuller/Caltech)

The lack of an explosion in the transformation of an average-sized star into a white dwarf makes these events less dramatic, but we have still seen evidence of this happening.

Caltech researcher Kareem El-Badry has previously discovered that widely separated binaries are less common in cases when one star has undergone the transformation into a white dwarf. One possible explanation is that repeated kicks during the red giant phase eventually break apart these loosely bound stellar pairs.

"If the orbital speed of the binaries is less than the kick speed, the wide binaries will become gravitationally unbound," Fuller said. Fuller's model also suggests something that astronomers are yet to see. He predicts that in some cases the kicks received by a red giant could send it pinballing toward a stellar companion, causing a massive explosion when the two collide.

Astronomers could now search the cosmos for such events, the discovery of which would help verify Fuller's model.

Fuller's results were presented at the 248th meeting of the American Astronomical Society in Pasadena. The study has been submitted to the Proceedings of the Astronomical Society of the Pacific.

Stages of Star Formation

18 June 2026 at 17:13
An area inside a star-forming molecular cloud. The background is covered with layers of gas and dust in blue, green and yellowish colors. Thicker clumps of cold dust, dark brown to black, block out light completely. Stars lie among and atop the clouds, from small orange ones to large white or blue ones. Waves and streams of glowing whitish gas are created by jets from protostars colliding with the surrounding material.
This NASA/ESA/CSA James Webb Space Telescope Picture of the Month shows the giant molecular cloud Orion A, an area of the sky replete with star-forming clouds.
ESA/Webb, NASA & CSA, T. Megeath, M. Zamani (ESA/Webb) Acknowledgement: M. H. Özsaraç

This image, captured by NASA’s James Webb Space Telescope and released on June 5, 2026, shows just a small portion of one of the Orion Molecular Clouds, a long and massive filament of cold gas and dust beyond the Orion Nebula. Every stage of star formation — from the youngest stellar embryos to protoplanetary discs to newly-minted pre-main sequence stars — is contained within this scene which stretches 150 light-years across.

Read more about this image.

Image credit: ESA/Webb, NASA & CSA, T. Megeath, M. Zamani (ESA/Webb); Acknowledgement: M. H. Özsaraç

The post Stages of Star Formation appeared first on NASA Science.

Stages of Star Formation

18 June 2026 at 17:13
An area inside a star-forming molecular cloud. The background is covered with layers of gas and dust in blue, green and yellowish colors. Thicker clumps of cold dust, dark brown to black, block out light completely. Stars lie among and atop the clouds, from small orange ones to large white or blue ones. Waves and streams of glowing whitish gas are created by jets from protostars colliding with the surrounding material.
This NASA/ESA/CSA James Webb Space Telescope Picture of the Month shows the giant molecular cloud Orion A, an area of the sky replete with star-forming clouds.
ESA/Webb, NASA & CSA, T. Megeath, M. Zamani (ESA/Webb) Acknowledgement: M. H. Özsaraç

This image, captured by NASA’s James Webb Space Telescope and released on June 5, 2026, shows just a small portion of one of the Orion Molecular Clouds, a long and massive filament of cold gas and dust beyond the Orion Nebula. Every stage of star formation — from the youngest stellar embryos to protoplanetary discs to newly-minted pre-main sequence stars — is contained within this scene which stretches 150 light-years across.

Read more about this image.

Image credit: ESA/Webb, NASA & CSA, T. Megeath, M. Zamani (ESA/Webb); Acknowledgement: M. H. Özsaraç

Sun-like star may have swallowed an exoplanet with help from a mysterious companion: 'You are what you eat, right?'

18 June 2026 at 17:00

Astronomers have a cosmic mystery on their hands, investigating a celestial crime scene to determine if a distant star has eaten a super-Earth exoplanet. The star may have had an accomplice — a failed star or "brown dwarf" companion — which may have steered the unfortunate planet toward its fiery doom.

The team charged with investigating this mystery first discovered hints of the crime when they found the star, TOI-5882, located around 1,300 light-years away, is surprisingly rich in the element lithium.

"You are what you eat, right?" team leader Brooke Kotten of the University of Michigan said in a statement. "We know that there's much more lithium in planetary material than there is in stars. So if a star eats a planet, it's going to take on a bunch of lithium."

So-called engulfment events such as this one occur very rapidly, on a timescale of a few days to a couple of weeks, which means catching stellar beings in the act of enjoying a planetary meal is extremely rare. Thus, astronomers have to act as cosmic crime scene investigators to reconstruct these events with the evidence at hand.

"That's what makes this field so exciting. You really are solving a mystery," Kotten said. "We can't just watch the crime happen, so we have to work with all the clues we're given to figure out whodunit."

One of the aims of these investigations is to discover the ways in which a star can devour a planet. One of the most common engulfment scenarios happens when a star runs out of hydrogen at its core at the end of its main sequence lifetime. This results in it swelling out to up to 100 times its original diameter, engulfing its attendant planets during its so-called red giant phase. This will occur in the solar system in around 5 billion years when the sun will puff out to around the orbit of Mars, swallowing the inner rocky planets, including our own.

However, Kotten and colleagues know this isn't what has happened in the TOI-5882 system, as this star hasn't yet become a red giant. Instead, the researchers think the sun-like star had assistance from its brown dwarf companion.

Companion brown dwarf of partner in crime?

Brown dwarfs get their slightly unfortunate nickname of "failed stars" because, despite forming from collapsing clouds of gas and dust, just like stars, they fail to grow to the masses needed to trigger the nuclear fusion of hydrogen to helium in their cores, the process that defines what a main-sequence star is. They're quite mysterious by existing in this sort of limbo between planet and star.

This particular brown dwarf has around 20 times the mass of Jupiter, or around 2% of the mass of the sun. That's not massive enough to trigger nuclear fusion, but is massive enough for it to have enough of a gravitational influence over planets orbiting TOI-5882. That means the team suspects this brown dwarf could have perturbed the orbit of this unfortunate planet enough to send it plummeting into its star.

This is something the scientists will need to investigate further. They may not have enough information yet to determine this planet's cause of death, but they do have some evidence that helps them identify the kind of world it would have been before it was obliterated. This comes from observations of the chemical composition and lithium content of 62 stars with similar ages and masses to TOI-5882.

"Lithium atoms delivered by planetary engulfment to a star are like sports fans arriving at a stadium," team member Seth Jacobson of Michigan State University said. "There may already be a few early arriving fans present, representing the initial amount of lithium in the stellar atmosphere, but they are quickly outnumbered."

A red glowing orb with a smaller red orb in the background.

An illustration of the lithium-enriched star TOI-5882 with its brown dwarf. (Image credit: Robert Lea (created with Canva))

From the lithium abundance they measured, the team has determined that this planet was a so-called super-Earth with a mass somewhere between two times that of our planet and the mass of the solar-system ice giant Neptune, which is around 18 times as massive as Earth.

"The fact that we can look at a star 1,300 light-years away and say with confidence, 'This star has more lithium than you would expect,' is a testament to both the precision of modern instrumentation and the hard interpretive work that goes into making sense of that signal," said Melinda Soares-Furtado, a senior author of the study and assistant professor at the University of Wisconsin. "And it's not like you have to cherry-pick the data to make it stand out. It's robust. No matter how you slice it, TOI-5882 is so enriched in lithium it shows up as being at least in the 97th percentile."

Soares-Furtado added that TOI-5882 is one of the few stars she has seen demonstrating evidence of planetary engulfment, although a few of the other stars in the control sample were enriched in lithium, albeit not to the extent of TOI-5882. That leaves another mystery for the team to solve, something that Soares-Furtado may well be quite content with.

"When I was growing up, I dreamed about becoming a private investigator," she said. "I think that explains a lot about where I ended up. I do feel like a detective."

The team's research was published on Monday (June 15) in The Astrophysical Journal.

NASA’s Fermi Mission Uncovers Possible Sibling Supernova Remnants

17 June 2026 at 18:15

6 min read

NASA’s Fermi Mission Uncovers Possible Sibling Supernova Remnants

A new study of two supernova remnants, the debris left behind after stars explode, suggests the explosions came from stellar siblings that once orbited each other. The first star’s detonation sent its binary companion hurtling through space, and then, after traveling for thousands of years, the surviving star blew up too.

Infrared, visible, and ultraviolet image of the area around the Jellyfish Nebula
This multiwavelength scene shows the Jellyfish Nebula supernova remnant (right), the interstellar cloud it’s interacting with, and a distinctive curving filament to its upper left. The filament, which is shown here both in optical and ultraviolet (UV) light, is the visible part of an overlapping supernova remnant, G189.6+3.3, that is more prominent in radio and X-rays. Visible light is shown in yellow, UV from NASA’s Neil Gehrels Swift Observatory is shown in violet, and infrared light from NASA’s retired WISE (Wide-field Infrared Survey Explorer) mission appears in cyan, red, and orange. Both remnants are located about 6,000 light-years away in the constellation Gemini. The brilliant star at far right is Propus, also known as Eta Geminorum.
NASA Goddard Space Flight Center and M. Michailidis et al. 2026; optical: DSS; infrared: NASA/WISE/JPL-Caltech/UCLA; ultraviolet: NASA/Swift

“Using 16 years of data from NASA’s Fermi Gamma-ray Space Telescope, our analysis uncovered gamma rays associated with a supernova remnant that was hidden in the glare of its neighbor, the Jellyfish Nebula, one of the brightest gamma-ray-emitting supernova remnants known,” said Miltiadis Michailidis, a postdoctoral fellow in the physics department at Stanford University in California. “There are so many striking connections between the two remnants that we conclude they’re likely related, giving us the first known example of a binary system where both stars have undergone supernova explosions.”

Michailidis presented the findings Wednesday at the 248th meeting of the American Astronomical Society in Pasadena, California. A paper describing the results will appear in a future edition of Nature Communications.

The study focused on a faint supernova remnant called G189.6+3.3, which is mainly visible in X-rays. It is upstaged by its brighter and better-known neighbor, the Jellyfish Nebula (IC 443). The two star wrecks, both located in the constellation Gemini, appear to partially overlap as seen in X-rays. Recent X-ray evidence suggests that hot plasma likely associated with G189.6+3.3 may extend across the entire region, a hint that the overlap may be nearly total.

A massive star explodes when its energy-producing core runs out of fuel and collapses under its own weight, triggering an explosion that blows the star apart. The explosion’s shock wave encloses a hot cloud of debris that rapidly expands into space. So far, astronomers have cataloged about 300 supernova remnants in our galaxy.  

The Fermi mission is part of NASA’s fleet of observatories monitoring the changing cosmos to help humanity better understand how the universe works. More than a decade ago, observations from Fermi’s LAT (Large Area Telescope) showed that the shock waves of supernova remnants accelerated particles to within a fraction of the speed of light, a process first proposed by physicist Enrico Fermi — the mission’s namesake — in 1949.

These high-speed particles, called cosmic rays, interact with interstellar gas to produce gamma rays, the highest-energy form of light. Protons make up 99% of cosmic ray particles. To prove that accelerated protons are responsible for the glow, astronomers search for a specific gamma-ray feature. When cosmic-ray protons smash into interstellar gas, they produce a short-lived particle called a neutral pion, which almost immediately decays into a pair of gamma rays. This emission occurs within a specific band of energies associated with the neutral pion’s mass and lies within the range detected by Fermi’s LAT instrument.

In 2013, Fermi observations proved that the Jellyfish Nebula, which is interacting with part of a glowing cloud of hydrogen gas known as Sharpless 249, produced gamma rays through this mechanism. Its neighbor, G189.6+3.3, was discovered in 1994 as part of an X-ray survey by the German-led ROSAT (Roentgen Satellite) mission.

A bright filament of gas lies between the overlapping remnants. New observations of this feature reveal that the shock wave from G189.6+3.3 slammed into dense interstellar gas there and dramatically slowed, key evidence that both remnants are interacting with the same cloud system.

Multiwavelength composite showing high-energy light from the G189 supernova remnant
The well-known supernova remnant IC 443 (right) has an older, fainter neighbor (shown here in blue-green and magenta) called G189.6+3.3. A filament of gas between them, glowing in visible and ultraviolet light (violet arc at center), traces the neighbor’s shock wave and shows that both remnants are interacting with the same molecular cloud, shown in red, orange, brown for infrared and radio data and yellow for visible light. Blue-green shows X-rays from the fainter remnant, while magenta shows gamma rays with energies greater than 10 billion electron volts; for comparison, visible light has energies between about 2 and 3 electron volts. In this view, high-energy light from the much brighter IC 443 has been removed for clarity. Gamma-ray emission near the filament stems from protons accelerated in the supernova’s shock wave as it expands into the cloud.
NASA Goddard Space Flight Center and M. Michailidis et al. 2026; radio, MWISP and ESA/Planck; infrared: NASA/WISE/JPL-Caltech/UCLA; optical: DSS; ultraviolet: NASA/Swift; X-ray: SRG/eROSITA; gamma ray: NASA/DOE/Fermi LAT Collaboration

Astronomers think the Jellyfish Nebula is also a candidate PeVatron, a cosmic particle accelerator capable of boosting protons to energies so high they could nearly escape our galaxy. Such particles can produce gamma rays with trillions of times more energy than visible light. Finding a second particle accelerator near the Jellyfish Nebula could offer scientists new clues for how supernova remnants develop into PeVatrons.

“The overlapping remnants, a connecting gas filament, and the availability of data from Fermi and other facilities motivated us to delve into this complex but little-studied region,” said co-author Marianne Lemoine-Goumard, an astrophysicist at the French National Centre for Scientific Research (CNRS) based at the University of Bordeaux. “With Fermi’s LAT instrument, we found gamma-ray emission associated with accelerated protons in the northern part of the fainter remnant. If both remnants are interacting with the same structure, then they must share a common distance from us.”

The team concludes the remnants lie about 6,000 light-years away, their explosion centers are separated by roughly 40 light-years projected onto the plane of the sky, and the original stars may have been 20 or more times the Sun’s mass.

Estimates of the remnants’ ages vary widely, but the team concludes that the age of the Jellyfish Nebula is 8,000 to 9,000 years, while G189.6+3.3 is between 20,000 to 110,000 years old. This means the delay between the explosions could have extended for up to 100,000 years.

In addition, the team conducted computer simulations of a million massive binary systems. They show that systems where the stars orbit close enough to exchange matter and interact during their lives can readily produce dual supernova explosions with similar separations and time delays as those found for the remnants. The team also estimated that the chance of randomly encountering this combination of observed spatial alignment and compatible distances to be less than 1%, strongly supporting a physical association.

“The evidence we’ve compiled — including observations across the spectrum, the chemical and physical properties of the remnants, simulations, and more — paints a compelling picture of a dual supernova event,” said Michailidis.

This study identifies a unique possible example of a binary system where both stars exploded as supernovae and left behind separate, detectable supernova remnants. Astronomers think that most massive stars form in binary or multiple-star systems. The Jellyfish Nebula/G189.6+3.3 complex offers astronomers a rare opportunity to study how massive binary stars evolve, exchange matter, explode, and experience velocity changes — called kicks — induced by the supernova blast. It also provides a powerful new laboratory for understanding how coupled supernova remnants behave, including how they accelerate particles, generate gamma rays, and shape their surrounding environments.

“Fermi’s gamma-ray observations of supernova remnants continue to reveal the dynamic lives of stars,” said Elizabeth Hays, the Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We can now connect the glowing remains of two massive stars to a powerful pair that evolved together over thousands of years.”

By Francis Reddy
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Media Contact:
Claire Andreoli
301-286-1940
NASA’s Goddard Space Flight Center, Greenbelt, Md.

NASA’s Fermi Mission Uncovers Possible Sibling Supernova Remnants

17 June 2026 at 18:15

6 min read

NASA’s Fermi Mission Uncovers Possible Sibling Supernova Remnants

A new study of two supernova remnants, the debris left behind after stars explode, suggests the explosions came from stellar siblings that once orbited each other. The first star’s detonation sent its binary companion hurtling through space, and then, after traveling for thousands of years, the surviving star blew up too.

Infrared, visible, and ultraviolet image of the area around the Jellyfish Nebula
This multiwavelength scene shows the Jellyfish Nebula supernova remnant (right), the interstellar cloud it’s interacting with, and a distinctive curving filament to its upper left. The filament, which is shown here both in optical and ultraviolet (UV) light, is the visible part of an overlapping supernova remnant, G189.6+3.3, that is more prominent in radio and X-rays. Visible light is shown in yellow, UV from NASA’s Neil Gehrels Swift Observatory is shown in violet, and infrared light from NASA’s retired WISE (Wide-field Infrared Survey Explorer) mission appears in cyan, red, and orange. Both remnants are located about 6,000 light-years away in the constellation Gemini. The brilliant star at far right is Propus, also known as Eta Geminorum.
NASA Goddard Space Flight Center and M. Michailidis et al. 2026; optical: DSS; infrared: NASA/WISE/JPL-Caltech/UCLA; ultraviolet: NASA/Swift

“Using 16 years of data from NASA’s Fermi Gamma-ray Space Telescope, our analysis uncovered gamma rays associated with a supernova remnant that was hidden in the glare of its neighbor, the Jellyfish Nebula, one of the brightest gamma-ray-emitting supernova remnants known,” said Miltiadis Michailidis, a postdoctoral fellow in the physics department at Stanford University in California. “There are so many striking connections between the two remnants that we conclude they’re likely related, giving us the first known example of a binary system where both stars have undergone supernova explosions.”

Michailidis presented the findings Wednesday at the 248th meeting of the American Astronomical Society in Pasadena, California. A paper describing the results will appear in a future edition of Nature Communications.

The study focused on a faint supernova remnant called G189.6+3.3, which is mainly visible in X-rays. It is upstaged by its brighter and better-known neighbor, the Jellyfish Nebula (IC 443). The two star wrecks, both located in the constellation Gemini, appear to partially overlap as seen in X-rays. Recent X-ray evidence suggests that hot plasma likely associated with G189.6+3.3 may extend across the entire region, a hint that the overlap may be nearly total.

A massive star explodes when its energy-producing core runs out of fuel and collapses under its own weight, triggering an explosion that blows the star apart. The explosion’s shock wave encloses a hot cloud of debris that rapidly expands into space. So far, astronomers have cataloged about 300 supernova remnants in our galaxy.  

The Fermi mission is part of NASA’s fleet of observatories monitoring the changing cosmos to help humanity better understand how the universe works. More than a decade ago, observations from Fermi’s LAT (Large Area Telescope) showed that the shock waves of supernova remnants accelerated particles to within a fraction of the speed of light, a process first proposed by physicist Enrico Fermi — the mission’s namesake — in 1949.

These high-speed particles, called cosmic rays, interact with interstellar gas to produce gamma rays, the highest-energy form of light. Protons make up 99% of cosmic ray particles. To prove that accelerated protons are responsible for the glow, astronomers search for a specific gamma-ray feature. When cosmic-ray protons smash into interstellar gas, they produce a short-lived particle called a neutral pion, which almost immediately decays into a pair of gamma rays. This emission occurs within a specific band of energies associated with the neutral pion’s mass and lies within the range detected by Fermi’s LAT instrument.

In 2013, Fermi observations proved that the Jellyfish Nebula, which is interacting with part of a glowing cloud of hydrogen gas known as Sharpless 249, produced gamma rays through this mechanism. Its neighbor, G189.6+3.3, was discovered in 1994 as part of an X-ray survey by the German-led ROSAT (Roentgen Satellite) mission.

A bright filament of gas lies between the overlapping remnants. New observations of this feature reveal that the shock wave from G189.6+3.3 slammed into dense interstellar gas there and dramatically slowed, key evidence that both remnants are interacting with the same cloud system.

Multiwavelength composite showing high-energy light from the G189 supernova remnant
The well-known supernova remnant IC 443 (right) has an older, fainter neighbor (shown here in blue-green and magenta) called G189.6+3.3. A filament of gas between them, glowing in visible and ultraviolet light (violet arc at center), traces the neighbor’s shock wave and shows that both remnants are interacting with the same molecular cloud, shown in red, orange, brown for infrared and radio data and yellow for visible light. Blue-green shows X-rays from the fainter remnant, while magenta shows gamma rays with energies greater than 10 billion electron volts; for comparison, visible light has energies between about 2 and 3 electron volts. In this view, high-energy light from the much brighter IC 443 has been removed for clarity. Gamma-ray emission near the filament stems from protons accelerated in the supernova’s shock wave as it expands into the cloud.
NASA Goddard Space Flight Center and M. Michailidis et al. 2026; radio, MWISP and ESA/Planck; infrared: NASA/WISE/JPL-Caltech/UCLA; optical: DSS; ultraviolet: NASA/Swift; X-ray: SRG/eROSITA; gamma ray: NASA/DOE/Fermi LAT Collaboration

Astronomers think the Jellyfish Nebula is also a candidate PeVatron, a cosmic particle accelerator capable of boosting protons to energies so high they could nearly escape our galaxy. Such particles can produce gamma rays with trillions of times more energy than visible light. Finding a second particle accelerator near the Jellyfish Nebula could offer scientists new clues for how supernova remnants develop into PeVatrons.

“The overlapping remnants, a connecting gas filament, and the availability of data from Fermi and other facilities motivated us to delve into this complex but little-studied region,” said co-author Marianne Lemoine-Goumard, an astrophysicist at the French National Centre for Scientific Research (CNRS) based at the University of Bordeaux. “With Fermi’s LAT instrument, we found gamma-ray emission associated with accelerated protons in the northern part of the fainter remnant. If both remnants are interacting with the same structure, then they must share a common distance from us.”

The team concludes the remnants lie about 6,000 light-years away, their explosion centers are separated by roughly 40 light-years projected onto the plane of the sky, and the original stars may have been 20 or more times the Sun’s mass.

Estimates of the remnants’ ages vary widely, but the team concludes that the age of the Jellyfish Nebula is 8,000 to 9,000 years, while G189.6+3.3 is between 20,000 to 110,000 years old. This means the delay between the explosions could have extended for up to 100,000 years.

In addition, the team conducted computer simulations of a million massive binary systems. They show that systems where the stars orbit close enough to exchange matter and interact during their lives can readily produce dual supernova explosions with similar separations and time delays as those found for the remnants. The team also estimated that the chance of randomly encountering this combination of observed spatial alignment and compatible distances to be less than 1%, strongly supporting a physical association.

“The evidence we’ve compiled — including observations across the spectrum, the chemical and physical properties of the remnants, simulations, and more — paints a compelling picture of a dual supernova event,” said Michailidis.

This study identifies a unique possible example of a binary system where both stars exploded as supernovae and left behind separate, detectable supernova remnants. Astronomers think that most massive stars form in binary or multiple-star systems. The Jellyfish Nebula/G189.6+3.3 complex offers astronomers a rare opportunity to study how massive binary stars evolve, exchange matter, explode, and experience velocity changes — called kicks — induced by the supernova blast. It also provides a powerful new laboratory for understanding how coupled supernova remnants behave, including how they accelerate particles, generate gamma rays, and shape their surrounding environments.

“Fermi’s gamma-ray observations of supernova remnants continue to reveal the dynamic lives of stars,” said Elizabeth Hays, the Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We can now connect the glowing remains of two massive stars to a powerful pair that evolved together over thousands of years.”

By Francis Reddy
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Media Contact:
Claire Andreoli
301-286-1940
NASA’s Goddard Space Flight Center, Greenbelt, Md.

The post NASA’s Fermi Mission Uncovers Possible Sibling Supernova Remnants appeared first on NASA Science.

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