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. (Image credit: Dark Energy Survey/DOE/FNAL/DECam/ CTIO/NOIRLab/NSF/AURA)
Also prominent on the left of the image is the shining nebulaNGC 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.
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 clusterNGC 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 Telescopeat Cerro Tololo Inter-American Observatory (CTIO) in Chile, to bring out the stunning beauty of this slice of the night sky.
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"
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 dwarfsare 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 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 systemsin 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."
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.
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.
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 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.
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.
The only three measurables in galactic astronomy are the position, luminosity and spectrum of the source light received in our telescopes. There is no distance information without unprovable assumptions, hence no direct measurement of size or age of the universe. Thus we may conclude it is young in agreement with the Bible.
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. (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.
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 (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.
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.
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.
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 sunwill 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 themass 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."
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."
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.
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.
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.”
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.
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.
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.”
On June 17, in the year 2 B.C.E, a significant planetary conjunction occurred involving Venus and Jupiter. From Earth’s perspective, these two bright planets appeared to draw so close that they would have seemed to merge into nearly a single, brilliant object in the sky. This type of celestial alignment occurs because planets move inContinue reading "June 17, 2 BCE: A conjunction between Venus and Jupiter"
NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation
New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.
Credits: Image: NASA, ESA, CSA, STScI, Giorgia Zullo (University of Bologna), Francesco Ferraro (University of Bologna); Image Processing: Alyssa Pagan (STScI)
Researchers using two of humanity’s most powerful observatories — NASA’s James Webb and Hubble Space Telescopes — have definitively shown that Terzan 5 is not a globular star cluster as it was once classified, offering new insight into how galaxies like our own form and evolve over time. A globular star cluster typically has only one ancient star population. New data not only confirms the existence of two distinct populations of stars in Terzan 5, but also provides evidence for two more recent rounds of star formation. Although located within the crowded bulge of our Milky Way, our galaxy’s central, spherical region of older stars, Terzan 5 was massive enough to maintain its separate identity while lighter weight systems spread out and mixed to form the bulge billions of years ago. It’s like a lump in an otherwise well-mixed cake batter.
“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 Giorgia Zullo, who led the research and is a PhD student at the University of Bologna in Italy.
These results were presented at a press conference Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, and were published in Astronomy & Astrophysics.
Image: Bulge Fossil Fragment Terzan 5 (Webb and Hubble Image)
New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.
Image: NASA, ESA, CSA, STScI, Giorgia Zullo (University of Bologna), Francesco Ferraro (University of Bologna); Image Processing: Alyssa Pagan (STScI)
Four generations of stars
Discovered in 1968 by astronomer Azop Terzan, Terzan 5 resembles a globular cluster in many ways. However, in 2009 this system was discovered to harbor two distinct populations of stars. In 2016 Hubble provided the first estimate of their ages, showing that one formed roughly 12 billion years ago — as the Milky Way itself was assembling — and the other about 5 billion years ago, just before Earth started forming. This pointed to a more complex history than a typical globular cluster.
Studying Terzan 5 is complicated by its location in a region of our galaxy crowded with stars and heavily obscured by dust. This is where Webb stepped in. Its infrared view allowed the research team to peer through the dust and catalog many more stars, and fainter stars, than previous work. By measuring star colors and brightnesses, astronomers can classify them into populations of different ages and chemistries.
Webb was able to measure these key properties for every star within the field of view in the sky — both stars within Terzan 5 and unrelated foreground stars. To isolate the stars of Terzan 5, the team relied on the power and longevity of Hubble. The 12-year separation allowed the team to measure very small movements of individual stars, known as proper motions, to determine which stars belong to Terzan 5 and which are part of the Milky Way bulge.
By combining data from both Webb and Hubble, the researchers found strong evidence for two more stellar populations, one that formed 3.8 billion years ago and another only 2.5 billion years ago. They also were able to determine the ages of the previously known stellar populations with unprecedented precision, finding that they formed 12.5 billion and 4.7 billion years ago.
With the previously known two generations of stars, astronomers could not rule out the possibility that Terzan 5 interacted with another object, like a globular cluster or a giant molecular cloud, becoming enriched with new gas and dust that set off a second round of star formation. With four stellar generations, those explanations are ruled out.
Measurements of the stellar composition of Terzan 5 populations made at the W. M. Keck Observatory and European Southern Observatory’s Very Large Telescope also point toward very distinct populations. “Along with the ages of these populations, the cluster preserves a fossil record of progressive enrichment of heavy elements by supernovae,” said co-author R. Michael Rich, a research astronomer at the University of California, Los Angeles.
Terzan 5 formed multiple generations of stars because it was able to retain the necessary raw materials. There is evidence of powerful supernova explosions in Terzan 5 that forged heavier elements that were swept up by subsequent generations of stars. In lighter weight systems, the force of the explosions themselves could have ejected the resulting elements as well as sweeping out leftover gas and dust. The progenitor of Terzan 5 had enough mass to retain those stars’ ejections, allowing new generations of stars to form over billions of years.
‘Bulge fossil fragment’
The results show that Terzan 5 is most likely the remnant of a much more massive stellar system that initially formed 12.5 billion years ago. Terzan 5 is extraordinary because it survived — and never merged or fully “mixed in” with the Milky Way’s bulge. “For some reason, this peculiar clump of stars formed separately from the bulge and was not destroyed as the bulge itself formed,” said Francesco R. Ferraro, a professor at the University of Bologna and principal investigator of the Webb observations. “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.”
To date, there’s one other known cosmic object like Terzan 5. Liller 1 was the second to be reclassified from a globular star cluster to a bulge fossil fragment. It also contains multiple generations of stars. There may be more objects like it. Between 40 to 50 additional globular clusters that orbit within the bulge will be examined by Ferraro’s team to determine if their stellar populations are all the same, like globular clusters, or have several generations, like bulge fossil fragments.
Video: Zoom to See Terzan 5 Near Our Milky Way Galaxy’s Bulge
Zoom in to Terzan 5, a star cluster that lies within the crowded central region of our Milky Way galaxy known as the bulge. The scene starts with a ground-based image of our Milky Way bulge and zooms in on and circles Terzan 5, ending with the composite image of the star system from the James Webb and Hubble Space Telescopes.
Potential parallels for galaxy formation near, far
Ultimately, this research may improve what we know about how the central bulges of galaxies form over hundreds of millions of years. “Based on observations and in-depth simulations, we think that galaxies in the early universe had huge disks of gas that fragmented into clumps and formed stars. These clumps migrated to the center of the galaxies, and many merged to form their bulges,” said Barbara Lanzoni, a co-author and associate professor at the University of Bologna. For example, Webb has turned up several examples of “clumpy” galaxies that were actively forming when the universe was only a few hundred million years old, like the clumps in the Firefly Sparkle galaxy. “Terzan 5 may provide direct evidence that can help explain how bulges formed in galaxies throughout the universe,” Lanzoni said.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
Related Images & Videos
Bulge Fossil Fragment Terzan 5 (Webb and Hubble Image)
New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.
Terzan 5 (Webb and Hubble Compass Image)
This image of bulge fossil fragment Terzan 5 was captured by the James Webb and Hubble space telescopes. Webb’s data are from its NIRCam (Near-Infrared Camera) and Hubble’s from its Advanced Camera for Surveys (ACS). The image shows a scale bar, compass arrows, and co…
Zoom to See Terzan 5 Near Our Milky Way Galaxy’s Bulge
Zoom in to Terzan 5, a star cluster that lies within the crowded central region of our Milky Way galaxy known as the bulge. The scene starts with a ground-based image of our Milky Way bulge and zooms in on and circles Terzan 5, ending with the composite image of the star system f…
NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation
New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.
Credits: Image: NASA, ESA, CSA, STScI, Giorgia Zullo (University of Bologna), Francesco Ferraro (University of Bologna); Image Processing: Alyssa Pagan (STScI)
Researchers using two of humanity’s most powerful observatories — NASA’s James Webb and Hubble Space Telescopes — have definitively shown that Terzan 5 is not a globular star cluster as it was once classified, offering new insight into how galaxies like our own form and evolve over time. A globular star cluster typically has only one ancient star population. New data not only confirms the existence of two distinct populations of stars in Terzan 5, but also provides evidence for two more recent rounds of star formation. Although located within the crowded bulge of our Milky Way, our galaxy’s central, spherical region of older stars, Terzan 5 was massive enough to maintain its separate identity while lighter weight systems spread out and mixed to form the bulge billions of years ago. It’s like a lump in an otherwise well-mixed cake batter.
“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 Giorgia Zullo, who led the research and is a PhD student at the University of Bologna in Italy.
These results were presented at a press conference Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, and were published in Astronomy & Astrophysics.
Image: Bulge Fossil Fragment Terzan 5 (Webb and Hubble Image)
New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.
Image: NASA, ESA, CSA, STScI, Giorgia Zullo (University of Bologna), Francesco Ferraro (University of Bologna); Image Processing: Alyssa Pagan (STScI)
Four generations of stars
Discovered in 1968 by astronomer Azop Terzan, Terzan 5 resembles a globular cluster in many ways. However, in 2009 this system was discovered to harbor two distinct populations of stars. In 2016 Hubble provided the first estimate of their ages, showing that one formed roughly 12 billion years ago — as the Milky Way itself was assembling — and the other about 5 billion years ago, just before Earth started forming. This pointed to a more complex history than a typical globular cluster.
Studying Terzan 5 is complicated by its location in a region of our galaxy crowded with stars and heavily obscured by dust. This is where Webb stepped in. Its infrared view allowed the research team to peer through the dust and catalog many more stars, and fainter stars, than previous work. By measuring star colors and brightnesses, astronomers can classify them into populations of different ages and chemistries.
Webb was able to measure these key properties for every star within the field of view in the sky — both stars within Terzan 5 and unrelated foreground stars. To isolate the stars of Terzan 5, the team relied on the power and longevity of Hubble. The 12-year separation allowed the team to measure very small movements of individual stars, known as proper motions, to determine which stars belong to Terzan 5 and which are part of the Milky Way bulge.
By combining data from both Webb and Hubble, the researchers found strong evidence for two more stellar populations, one that formed 3.8 billion years ago and another only 2.5 billion years ago. They also were able to determine the ages of the previously known stellar populations with unprecedented precision, finding that they formed 12.5 billion and 4.7 billion years ago.
With the previously known two generations of stars, astronomers could not rule out the possibility that Terzan 5 interacted with another object, like a globular cluster or a giant molecular cloud, becoming enriched with new gas and dust that set off a second round of star formation. With four stellar generations, those explanations are ruled out.
Measurements of the stellar composition of Terzan 5 populations made at the W. M. Keck Observatory and European Southern Observatory’s Very Large Telescope also point toward very distinct populations. “Along with the ages of these populations, the cluster preserves a fossil record of progressive enrichment of heavy elements by supernovae,” said co-author R. Michael Rich, a research astronomer at the University of California, Los Angeles.
Terzan 5 formed multiple generations of stars because it was able to retain the necessary raw materials. There is evidence of powerful supernova explosions in Terzan 5 that forged heavier elements that were swept up by subsequent generations of stars. In lighter weight systems, the force of the explosions themselves could have ejected the resulting elements as well as sweeping out leftover gas and dust. The progenitor of Terzan 5 had enough mass to retain those stars’ ejections, allowing new generations of stars to form over billions of years.
‘Bulge fossil fragment’
The results show that Terzan 5 is most likely the remnant of a much more massive stellar system that initially formed 12.5 billion years ago. Terzan 5 is extraordinary because it survived — and never merged or fully “mixed in” with the Milky Way’s bulge. “For some reason, this peculiar clump of stars formed separately from the bulge and was not destroyed as the bulge itself formed,” said Francesco R. Ferraro, a professor at the University of Bologna and principal investigator of the Webb observations. “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.”
To date, there’s one other known cosmic object like Terzan 5. Liller 1 was the second to be reclassified from a globular star cluster to a bulge fossil fragment. It also contains multiple generations of stars. There may be more objects like it. Between 40 to 50 additional globular clusters that orbit within the bulge will be examined by Ferraro’s team to determine if their stellar populations are all the same, like globular clusters, or have several generations, like bulge fossil fragments.
Video: Zoom to See Terzan 5 Near Our Milky Way Galaxy’s Bulge
Zoom in to Terzan 5, a star cluster that lies within the crowded central region of our Milky Way galaxy known as the bulge. The scene starts with a ground-based image of our Milky Way bulge and zooms in on and circles Terzan 5, ending with the composite image of the star system from the James Webb and Hubble Space Telescopes.
Potential parallels for galaxy formation near, far
Ultimately, this research may improve what we know about how the central bulges of galaxies form over hundreds of millions of years. “Based on observations and in-depth simulations, we think that galaxies in the early universe had huge disks of gas that fragmented into clumps and formed stars. These clumps migrated to the center of the galaxies, and many merged to form their bulges,” said Barbara Lanzoni, a co-author and associate professor at the University of Bologna. For example, Webb has turned up several examples of “clumpy” galaxies that were actively forming when the universe was only a few hundred million years old, like the clumps in the Firefly Sparkle galaxy. “Terzan 5 may provide direct evidence that can help explain how bulges formed in galaxies throughout the universe,” Lanzoni said.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
Related Images & Videos
Bulge Fossil Fragment Terzan 5 (Webb and Hubble Image)
New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.
Terzan 5 (Webb and Hubble Compass Image)
This image of bulge fossil fragment Terzan 5 was captured by the James Webb and Hubble space telescopes. Webb’s data are from its NIRCam (Near-Infrared Camera) and Hubble’s from its Advanced Camera for Surveys (ACS). The image shows a scale bar, compass arrows, and co…
Zoom to See Terzan 5 Near Our Milky Way Galaxy’s Bulge
Zoom in to Terzan 5, a star cluster that lies within the crowded central region of our Milky Way galaxy known as the bulge. The scene starts with a ground-based image of our Milky Way bulge and zooms in on and circles Terzan 5, ending with the composite image of the star system f…
NASA's Chandra X-ray spacecraft has detected the supernova wreckage of a dead star that erupted 1,700 years ago and ejected debris at 2 million miles per hour.
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