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Hubble Glimpses Merging Galaxy Clusters

18 June 2026 at 12:36

2 min read

Hubble Glimpses Merging Galaxy Clusters

Several massive elliptical galaxies appear to sit in a nearly horizontal line across the center of the image. Numerous spiral, lenticular, and smaller elliptical galaxies dot the space surrounding the giant ellipticals.
This NASA Hubble Space Telescope image features a swarm of galaxies in the galaxy cluster called CL0016+1609 or MACS J0018.5+1626.
NASA, ESA, H. Ebeling (University of Hawaii), D. Coe (STScI, ESA, JWST); Image Processing: G. Kober (NASA/Catholic University of America)

This NASA Hubble Space Telescope image features a galaxy cluster, called CL0016+1609 or MACS J0018.5+1626, that is very bright at X-ray wavelengths and is one of the most extensively studied clusters at X-ray and radio wavelengths. The X-ray observations of this cluster revealed that it is two clusters merging along our line of sight.

Researchers requested time to observe CL0016+1609 with Hubble’s Advanced Camera for Surveys because that data would help them accurately measure the cluster’s dark-matter distribution, which helps them study the merger and the role of CL0016+1609 in the large-scale structure of the universe. Hubble can’t directly see dark matter, but its infrared and visible light observations can detect dark matter’s gravitational lensing effects on the normal matter Hubble observes.

The data in this image also includes observations with Hubble’s Wide Field Camera 3 taken as part of an observing program that obtained the first Hubble infrared images of 46 massive galaxy clusters and looked for distant galaxies gravitationally lensed by these clusters. Called RELICS (Reionization Lensing Cluster Survey), this survey found some 300 high-redshift candidate galaxies lensed by these clusters.

You can see the faint vertical arc of one of these distant galaxies in the image above. Look for it just to the left of the large elliptical galaxies in the center of the image. Another brighter, though shorter arc is visible just above and to the right of the large elliptical galaxies in the center of the image.

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

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.

Hubble Glimpses Merging Galaxy Clusters

18 June 2026 at 12:36

2 min read

Hubble Glimpses Merging Galaxy Clusters

Several massive elliptical galaxies appear to sit in a nearly horizontal line across the center of the image. Numerous spiral, lenticular, and smaller elliptical galaxies dot the space surrounding the giant ellipticals.
This NASA Hubble Space Telescope image features a swarm of galaxies in the galaxy cluster called CL0016+1609 or MACS J0018.5+1626.
NASA, ESA, H. Ebeling (University of Hawaii), D. Coe (STScI, ESA, JWST); Image Processing: G. Kober (NASA/Catholic University of America)

This NASA Hubble Space Telescope image features a galaxy cluster, called CL0016+1609 or MACS J0018.5+1626, that is very bright at X-ray wavelengths and is one of the most extensively studied clusters at X-ray and radio wavelengths. The X-ray observations of this cluster revealed that it is two clusters merging along our line of sight.

Researchers requested time to observe CL0016+1609 with Hubble’s Advanced Camera for Surveys because that data would help them accurately measure the cluster’s dark-matter distribution, which helps them study the merger and the role of CL0016+1609 in the large-scale structure of the universe. Hubble can’t directly see dark matter, but its infrared and visible light observations can detect dark matter’s gravitational lensing effects on the normal matter Hubble observes.

The data in this image also includes observations with Hubble’s Wide Field Camera 3 taken as part of an observing program that obtained the first Hubble infrared images of 46 massive galaxy clusters and looked for distant galaxies gravitationally lensed by these clusters. Called RELICS (Reionization Lensing Cluster Survey), this survey found some 300 high-redshift candidate galaxies lensed by these clusters.

You can see the faint vertical arc of one of these distant galaxies in the image above. Look for it just to the left of the large elliptical galaxies in the center of the image. Another brighter, though shorter arc is visible just above and to the right of the large elliptical galaxies in the center of the image.

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

The post Hubble Glimpses Merging Galaxy Clusters appeared first on NASA Science.

Scientists Say a New Universe Could Form Inside a Dying Star

18 June 2026 at 07:15
Inside GravastarA new study suggests that the collapse of a massive star could spark the creation of a tiny expanding universe rather than a black hole. The resulting object, called a gravastar, would avoid the singularity and event horizon that make black holes so puzzling. Massive stars produce light and heat through nuclear fusion in their [...]

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.

Dark Matter Still a Possibility at the Heart of the Milky Way

17 June 2026 at 15:47

In an ambitious collaboration bridging continents and disciplines, researchers from the University of Vienna and the Lawrence Berkeley National Laboratory have revisited one of astrophysics’ most enigmatic phenomena—the Galactic Center Excess (GCE). For over a decade, the GCE, a subtle yet pervasive gamma-ray glow enveloping the Milky Way’s core, has stimulated intense debate and exploration within the scientific community. This new study, leveraging cutting-edge machine learning methodologies, offers fresh perspectives that reinvigorate the dark matter hypothesis as a viable explanation for the GCE, a prospect previously challenged by conventional analyses.

The Galactic Center Excess presents itself as a roughly spherical halo of gamma-ray emission, extending over thousands of light years around our galaxy’s nucleus. This faint glow eludes straightforward interpretation, primarily due to the complexities of the astronomical environment it inhabits. The region is not only densely packed with astrophysical sources but also exhibits extraordinarily bright and intricately structured gamma-ray emissions, complicating efforts to disentangle the origins of the GCE signal.

Before this study, two primary interpretations vied for dominance in explaining the GCE. One posited that the excess emanates from annihilations of dark matter particles, hypothetical constituents of the universe that interact weakly with ordinary matter and light. Dark matter, while composing approximately 85% of the universe’s matter content, remains elusive, and detecting its indirect signatures through gamma-ray emissions has been a tantalizing goal. The second hypothesis attributes the gamma-ray glow to a population of millisecond pulsars—rapidly rotating neutron stars known for their intense electromagnetic emissions. These pulsars, if sufficiently numerous and faint, could collectively mimic the characteristics of the observed GCE.

However, the astrophysical scenario faced a significant analytical hurdle. Earlier statistical approaches, while sophisticated, did not fully incorporate a vital dimension of the observed data: the energy spectrum of individual gamma-ray photons. Prior analyses predominantly focused on spatial distribution patterns, searching for point sources that could represent pulsars or diffuse emissions consistent with dark matter annihilation. Without the spectral dimension, conclusions remained inconclusive, often biased toward interpretations favoring bright unresolved sources.

The breakthrough in this new research is the implementation of an advanced machine-learning framework that simultaneously evaluates the spatial location and energy distribution of gamma-ray photons captured by telescopes. Training this model required generating over a million simulated gamma-ray skies, replicating a diverse range of scenarios that include both dark matter and pulsar contributions. By synthesizing these rich datasets, the model attains unprecedented sensitivity and discrimination power, uniquely capable of parsing subtle differences in the gamma-ray energy patterns correlated with different source populations.

The enriched analysis dramatically alters the interpretation landscape. The findings demonstrate that the putative point sources—if responsible for the GCE—would need to be extraordinarily faint, to the point where their individual characteristics blur into a diffuse glow nearly indistinguishable from what dark matter annihilation models predict. This faintness requirement for pulsars implies an astronomical population count exceeding 35,000 millisecond pulsars in the central Milky Way region. Such a number challenges existing astrophysical models and contrasts with previous studies that suggested only a few hundred to a few thousand such sources would suffice to explain the gamma-ray excess.

This new quantitative insight reopens the door for dark matter as a plausible explanation. While previous evidence tended to discount dark matter in favor of point sources, the subtlety revealed by including photon energy analysis counters these assertions. It underscores the present limitations in conclusively resolving the GCE’s origin, emphasizing that the dark matter scenario remains firmly on the table alongside pulsar hypotheses.

The difficulty in resolving the GCE nature also reflects broader challenges in high-energy astrophysics—particularly in crowded celestial environments like our galaxy’s core, where overlapping emissions from stars, supernova remnants, and other celestial objects confound the interpretation of indirect dark matter signals. Machine learning, as applied here, represents a transformative tool, capable of synthesizing immense, multidimensional datasets to disentangle complex astrophysical phenomena.

Scientists caution that these findings do not constitute direct evidence for dark matter annihilation; instead, they highlight the incomplete nature of current data interpretations. The inability to definitively favor pulsars over dark matter annihilation underscores the need for next-generation gamma-ray observatories and continued advances in modeling techniques that can incorporate even more nuanced data features, such as temporal variability and polarization signatures.

This research embodies the synergy between theoretical physics, computational innovation, and observational astrophysics, demonstrating how modern data-driven approaches can revitalize longstanding scientific debates. As gamma-ray detection technologies evolve and more data become available, the methodology pioneered here promises further refinement, potentially leading to breakthroughs in identifying signals from the elusive dark sector of the universe.

The Galactic Center Excess remains one of the most compelling mysteries in contemporary astrophysics, symbolizing the frontier where known astrophysical processes intersect with profound questions about the fundamental composition of the universe. Whether future research will tilt the scales decisively in favor of dark matter or pulsars, this study exemplifies the power of interdisciplinary collaboration and sophisticated computational methods to deepen our cosmic understanding.

Moreover, the implications extend beyond academic curiosity. Deciphering the GCE carries the promise of shedding light on the nature of dark matter, a cornerstone of cosmological structure formation and evolution. Success in this endeavor could unveil new physics beyond the Standard Model, revolutionizing our conception of the universe’s fabric and the forces that govern it at the most fundamental level.

As researchers continue to probe the galactic center’s gamma-ray glow, the intellectual journey itself enriches science, reflecting a profound human drive to illuminate the obscure workings of the cosmos. This study marks a significant stride in that journey, blending technology, theory, and observation to navigate a complex astrophysical puzzle whose solution may redefine our place in the universe.


Subject of Research: The Galactic Center Excess in gamma-ray observations and its implications for dark matter and millisecond pulsar populations.

Article Title: Energy Distribution of the Galactic Center Excess’s Sources

News Publication Date: 12-Jun-2026

Web References:
DOI link


Keywords

Galactic Center Excess, gamma rays, Milky Way, dark matter, millisecond pulsars, machine learning, astrophysics, high-energy astrophysics, neutron stars, indirect dark matter detection, gamma-ray astronomy, astrophysical sources

NASA’s Webb Catches Exoplanet Getting Roasted

16 June 2026 at 22:15
 
4 Min Read

NASA’s Webb Catches Exoplanet Getting Roasted

Illustration of a planet and a star, labeled artist’s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Credits:
Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

4 min read

NASA’s Webb Catches Exoplanet Getting Roasted

One well-done gas giant, coming right up! That’s the latest from researchers analyzing NASA’s James Webb Space Telescope’s observations of HD 80606 b, an exoplanet four times the mass of Jupiter with an extremely elliptical orbit that sweeps close by its Sun-like star. The research team is presenting their study and preliminary findings Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, California.

“Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme,” said Tiffany Kataria, the study’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California. “We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet’s highly eccentric orbit creates a completely different beast.”

As the planet plunges close to its star, Webb shows its temperature skyrockets by 1,100 degrees Fahrenheit. Previous studies have shown that radical temperature swings can cause an exoplanet’s chemistry and clouds to change in real time. According to the research team, the dynamic conditions of HD 80606 b make the planet an ideal target to observe these changes with Webb’s powerful instruments.

Image: Artist’s concept exoplanet HD 80606 b

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

“Observing a planet like HD 80606 b is actually very efficient because its unusual orbit, with the corresponding swings in temperature and chemical composition, allow us to gather data under varying conditions in just hours and apply those findings to other hot Jupiters or more conventional exoplanets,” said Laura C. Mayorga, co-investigator on the study and an exoplanet astronomer at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.

Measurements of temperature and chemical composition were done with spectroscopy, a technique scientists use to break light into its component colors to reveal information about the composition, temperature, motion, and physical properties of objects in space. The team used Webb’s MIRI (Mid-Infrared Instrument) for an extended observation of HD 80606 b before, during, and after its periastron, or closest pass by its star. During periastron, the planet also passed behind the star from Webb’s perspective in what’s known as a secondary eclipse. The observation was years in the planning, as scheduling the time to catch the planet at this point was complex given its extremely elliptical 111-day orbit, and Webb’s own restrictions on where it can look during specific times of the year, based on Earth’s position in orbit around the Sun.

Researchers say they have only begun to peel back the layers of an incredibly rich dataset, but they can clearly see a dramatic shift in the exoplanet’s temperature. “Webb has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data,” said Kataria.

In fact, the planet had already been dubbed the “roasted exoplanet” and even got its own poster in NASA’s popular series. NASA’s now-retired Spitzer Space Telescope laid the groundwork of infrared observations of HD 80606 b, showing that more detailed spectroscopic data from Webb would be especially compelling.

“Spitzer did amazing work on this exoplanet, and now Webb is building on that legacy by enabling us to drill down to distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress,” said Ryan Challener, co-author and research associate at the Cornell Center for Astrophysics and Planetary Science. “There’s so much to learn from this one dataset here — we really are just getting started deciphering what Webb has to tell us.”

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).

For more information on Webb, visit:

science.nasa.gov/webb

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Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.

HD 80606 b (Artist’s Concept)

This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.

Related Links

Este Artículo en Español – “Telescopio Webb de la NASA Detecta un Exoplaneto Asandose”

Read:  Webb’s Impact on Exoplanet Research

Watch:  How to Study Exoplanets: Webb and Challenges

Explore:  Eyes on Exoplanets

Print: The Roasted Exoplanet Poster

More Webb: News | Images | Science | Home Page


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Last Updated
Jun 17, 2026
Contact
Media

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Leah Ramsay
Space Telescope Science Institute
Baltimore, Maryland

Hannah Braun
Space Telescope Science Institute
Baltimore, Maryland

NASA’s Webb Catches Exoplanet Getting Roasted

16 June 2026 at 22:15
 
4 Min Read

NASA’s Webb Catches Exoplanet Getting Roasted

Illustration of a planet and a star, labeled artist’s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Credits: Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

4 min read

NASA’s Webb Catches Exoplanet Getting Roasted

One well-done gas giant, coming right up! That’s the latest from researchers analyzing NASA’s James Webb Space Telescope’s observations of HD 80606 b, an exoplanet four times the mass of Jupiter with an extremely elliptical orbit that sweeps close by its Sun-like star. The research team is presenting their study and preliminary findings Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, California.

“Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme,” said Tiffany Kataria, the study’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California. “We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet’s highly eccentric orbit creates a completely different beast.”

As the planet plunges close to its star, Webb shows its temperature skyrockets by 1,100 degrees Fahrenheit. Previous studies have shown that radical temperature swings can cause an exoplanet’s chemistry and clouds to change in real time. According to the research team, the dynamic conditions of HD 80606 b make the planet an ideal target to observe these changes with Webb’s powerful instruments.

Image: Artist’s concept exoplanet HD 80606 b

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

“Observing a planet like HD 80606 b is actually very efficient because its unusual orbit, with the corresponding swings in temperature and chemical composition, allow us to gather data under varying conditions in just hours and apply those findings to other hot Jupiters or more conventional exoplanets,” said Laura C. Mayorga, co-investigator on the study and an exoplanet astronomer at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.

Measurements of temperature and chemical composition were done with spectroscopy, a technique scientists use to break light into its component colors to reveal information about the composition, temperature, motion, and physical properties of objects in space. The team used Webb’s MIRI (Mid-Infrared Instrument) for an extended observation of HD 80606 b before, during, and after its periastron, or closest pass by its star. During periastron, the planet also passed behind the star from Webb’s perspective in what’s known as a secondary eclipse. The observation was years in the planning, as scheduling the time to catch the planet at this point was complex given its extremely elliptical 111-day orbit, and Webb’s own restrictions on where it can look during specific times of the year, based on Earth’s position in orbit around the Sun.

Researchers say they have only begun to peel back the layers of an incredibly rich dataset, but they can clearly see a dramatic shift in the exoplanet’s temperature. “Webb has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data,” said Kataria.

In fact, the planet had already been dubbed the “roasted exoplanet” and even got its own poster in NASA’s popular series. NASA’s now-retired Spitzer Space Telescope laid the groundwork of infrared observations of HD 80606 b, showing that more detailed spectroscopic data from Webb would be especially compelling.

“Spitzer did amazing work on this exoplanet, and now Webb is building on that legacy by enabling us to drill down to distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress,” said Ryan Challener, co-author and research associate at the Cornell Center for Astrophysics and Planetary Science. “There’s so much to learn from this one dataset here — we really are just getting started deciphering what Webb has to tell us.”

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).

For more information on Webb, visit:

science.nasa.gov/webb

Downloads & Related Information

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

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.

HD 80606 b (Artist’s Concept)

This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.

Related Links

Este Artículo en Español – “Telescopio Webb de la NASA Detecta un Exoplaneto Asandose”

Read:  Webb’s Impact on Exoplanet Research

Watch:  How to Study Exoplanets: Webb and Challenges

Explore:  Eyes on Exoplanets

Print: The Roasted Exoplanet Poster

More Webb: News | Images | Science | Home Page

Share

Details

Last Updated
Jun 16, 2026
Contact
Media

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Leah Ramsay
Space Telescope Science Institute
Baltimore, Maryland

Hannah Braun
Space Telescope Science Institute
Baltimore, Maryland

The post NASA’s Webb Catches Exoplanet Getting Roasted appeared first on NASA Science.

NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation

16 June 2026 at 18:15
 
7 Min Read

NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation

A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space, which is clearer at the edges, is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb, and sparser at the edges of the image. Several larger orange stars, particularly those largest near the edges of the frame, have prominent diffraction spikes.
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)

A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space, which is clearer at the edges, is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb, and sparser at the edges of the image. Several larger orange stars, particularly those largest near the edges of the frame, have prominent diffraction spikes.
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.
Video: NASA, ESA, CSA, Alyssa Pagan (STScI); Acknowledgment: ESO, Pan-STARRS, DSS2, Akira Fujii

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.

To learn more about Webb, visit:

https://science.nasa.gov/webb

To learn more about Hubble, visit:

https://science.nasa.gov/hubble

Downloads & Related Information

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

A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space, which is clearer at the edges, is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb, and sparser at the edges of the image. Several larger orange stars, particularly those largest near the edges of the frame, have prominent diffraction spikes.

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 titled u201cJames Webb and Hubble Space Telescopes; Terzan 5,u201d with compass arrows and color key. A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb. At the bottom left are compass arrows indicating the orientation of the image on the sky. The east arrow points toward 12 ou2019clock. The north arrow points toward 3 ou2019clock. At the bottom right is a scale bar labeled 2 light-years. The length of the scale bar is about one seventh of the total image. Below the image is a color key showing which Hubble ACS/WFC and Webb NIRCam filters were used to create the image, and which visible-light color is assigned to each filter. Hubble ACS filters, from left to right: F606W is blue and F814W is teal. Webb NIRCam filters: F115W is orange, F200W is red.

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…

Telescope image shows the Milky Way. The Milky Wayu2019s central region runs from top left to bottom right and has dark lanes of dust overlapping bright regions of stars. At the center is a label, Milky Way Center. The entire image is mostly black with pinpoints of light throughout. Thin blue lines connect several stars of two constellations, including the shape of a teapot representing Sagittarius at left and a long, arced line representing Scorpius at right. On the left, a large illustration of a centaur represents Sagittarius, with the teapot over his right arm. On the right, a large illustration of a scorpion represents Scorpius, with the line running throughout the center of its body.

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…

Related Links

Read more: Hubble’s star clusters

Explore more: ViewSpace | Forms of light: the Cluster Omega Centauri

Watch: Globular Clusters, Stellar Pockets

Watch: Sorting the Stars in Omega Centauri

Webb: News | Images | Science | Home Page

Hubble: News | Images | Science | Home Page


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Details

Last Updated
Jun 16, 2026
Contact
Media

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland

Claire Blome
Space Telescope Science Institute
Baltimore, Maryland

NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation

16 June 2026 at 18:15
 
7 Min Read

NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation

A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space, which is clearer at the edges, is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb, and sparser at the edges of the image. Several larger orange stars, particularly those largest near the edges of the frame, have prominent diffraction spikes.
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)

A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space, which is clearer at the edges, is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb, and sparser at the edges of the image. Several larger orange stars, particularly those largest near the edges of the frame, have prominent diffraction spikes.
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.
Video: NASA, ESA, CSA, Alyssa Pagan (STScI); Acknowledgment: ESO, Pan-STARRS, DSS2, Akira Fujii

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.

To learn more about Webb, visit:

https://science.nasa.gov/webb

To learn more about Hubble, visit:

https://science.nasa.gov/hubble

Downloads & Related Information

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

A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space, which is clearer at the edges, is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb, and sparser at the edges of the image. Several larger orange stars, particularly those largest near the edges of the frame, have prominent diffraction spikes.

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 titled u201cJames Webb and Hubble Space Telescopes; Terzan 5,u201d with compass arrows and color key. A dramatically crowded starfield that looks like a just-shaken snow globe. The black background of space is covered by thousands of tiny white, orange, and blue points of light, which are stars. The stars are most concentrated in the center, forming a roughly circular orb. At the bottom left are compass arrows indicating the orientation of the image on the sky. The east arrow points toward 12 ou2019clock. The north arrow points toward 3 ou2019clock. At the bottom right is a scale bar labeled 2 light-years. The length of the scale bar is about one seventh of the total image. Below the image is a color key showing which Hubble ACS/WFC and Webb NIRCam filters were used to create the image, and which visible-light color is assigned to each filter. Hubble ACS filters, from left to right: F606W is blue and F814W is teal. Webb NIRCam filters: F115W is orange, F200W is red.

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…

Telescope image shows the Milky Way. The Milky Wayu2019s central region runs from top left to bottom right and has dark lanes of dust overlapping bright regions of stars. At the center is a label, Milky Way Center. The entire image is mostly black with pinpoints of light throughout. Thin blue lines connect several stars of two constellations, including the shape of a teapot representing Sagittarius at left and a long, arced line representing Scorpius at right. On the left, a large illustration of a centaur represents Sagittarius, with the teapot over his right arm. On the right, a large illustration of a scorpion represents Scorpius, with the line running throughout the center of its body.

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…

Related Links

Read more: Hubble’s star clusters

Explore more: ViewSpace | Forms of light: the Cluster Omega Centauri

Watch: Globular Clusters, Stellar Pockets

Watch: Sorting the Stars in Omega Centauri

Webb: News | Images | Science | Home Page

Hubble: News | Images | Science | Home Page

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Last Updated
Jun 16, 2026
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Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland

Claire Blome
Space Telescope Science Institute
Baltimore, Maryland

The post NASA Webb, Hubble Reveal History of Relic of Milky Way’s Formation appeared first on NASA Science.

Astronomers Confirm Dark Energy After Shock Challenge Rocked Cosmology

16 June 2026 at 12:23
Supernova Purple Starburst in SpaceA major challenge to dark energy, the mysterious force believed to be driving the universe’s accelerating expansion, has been overturned by a new study. Astronomers say a new analysis has reinforced one of the most important discoveries in modern cosmology, finding that the universe is still expanding at an accelerating rate. The result counters a [...]

NASA’s Chandra Finds Unexpected Fireworks in Aftermath of Stellar Explosions

15 June 2026 at 19:45
6 Min Read

NASA’s Chandra Finds Unexpected Fireworks in Aftermath of Stellar Explosions

A full field composite image of M83 with X-rays from Chandra (red, green, and blue) and optical light data from Hubble (red, green, and blue).
A composite image of the nearby galaxy Messier 83, and short timelapse videos of two curious supernova remnants hidden inside.
X-ray: NASA/CXC/SAO; Optical: NASA/ESA/AURA/STScI, Hubble Heritage Team, W. Blair (STScI/Johns Hopkins University) and R. O’Connell (University of Virginia); Image Processing: NASA/CXC/SAO/A. Jubett, L. Frattare and P. Edmonds

The aftermath of a supernova, a stellar explosion, is usually a slowly fading cloud of hot gas. So when astronomers pointed NASA’s Chandra X-ray Observatory at the nearby galaxy Messier 83 (M83), they did not expect to find a population of supernova remnants, or the debris from these explosions, showing dramatic changes in their brightness. The new results were presented at the American Astronomical Society meeting in Pasadena, California, and published in The Astrophysical Journal.

The galaxy M83, located about 15 million light-years from Earth, is forming stars at a high rate. Researchers analyzed 14 years of Chandra data of the galaxy, spanning 2000 to 2014.

Using this extensive set of data, the researchers caught surprising variations in the X-ray brightness of sources previously identified as supernova remnants. The researchers expected supernova remnants older than a century or so to fade gradually in X-rays, but not change dramatically in brightness.

The team found that roughly half of the 22 X-ray sources associated with supernova remnants in their sample showed changes in X-ray brightness over the 14-year span of observations — a result that was completely unexpected.

“We knew that individual X-ray sources could vary dramatically,” said Andrea Prestwich, of the Catholic University of America who led the study. “But finding that so many supernova remnants were behaving this way was a real surprise. Something unusual is going on in these objects. Pinpointing the cause remains a challenge, as M83’s distance limits the detail we can observe.”

One of the 22 variable supernova remnants has a straightforward explanation: SN 1957D, the debris from a supernova first observed nearly 70 years ago, is ramming into material surrounding the explosion site, producing the observed X-ray flares. But this cannot explain the rest of the sample. There is no evidence to suggest that all 22 remnants were formed within the last century. Something else must be driving the variability.

The most likely explanation is that the team has uncovered a population of stellar survivors stars that lived through their partner’s destruction in a supernova explosion. In this scenario, each variable X-ray source began as a pair of massive stars orbiting each other. The more massive star collapsed and exploded as a supernova, leaving behind a black hole or ultra-dense neutron star. Its companion survived.

A full field composite image of M83 with X-rays from Chandra (red, green, and blue) and optical light data from Hubble (red, green, and blue).
Galaxy M83 in X-ray and Optical Light.
X-ray: NASA/CXC/SAO; Optical: NASA/ESA/AURA/STScI, Hubble Heritage Team, W. Blair (STScI/Johns Hopkins University) and R. O’Connell (University of Virginia); Image Processing: NASA/CXC/SAO/A. Jubett, L. Frattare and P. Edmonds

“It may be that this galaxy contains a collection of supernova remnants where one massive star survives the supernova and becomes locked into an orbit with a black hole or neutron star,” said co-author Michael McCollough of the Center for Astrophysics | Harvard & Smithsonian (CfA). “The neutron star or black hole can then start pulling material from the massive star’s surface.”

That infalling material is superheated by the intense gravitational pull, producing the X-rays Chandra detects. These types of systems, known as high-mass X-ray binaries (HMXBs), are among the most variable X-ray sources in the universe. Researchers say they may be the cause of the variations seen in M83’s supernova remnants.

Astronomers have known about HMXBs for decades, but the difference with this group in M83 is their connection to supernova remnants. Previously, only a handful of supernova remnants associated with HMXBs had been identified across observations of all galaxies. It is unprecedented to find more than 20 strong candidates in just one galaxy.

The authors found that the variable supernova remnants are in regions with higher concentrations of massive stars than in other parts of the galaxy, increasing the chances of a link between the remnants and HMXBs.

There is another possible explanation: Instead of pulling in material from a companion star, the black hole or neutron star may be recapturing some of the material blasted outward by the original explosion.

“This could be an example of cosmic recycling, where debris from the explosion falls back onto the very object the supernova created,” said co-author Roy Kilgard of Wesleyan University. “And it’s quite possible that both explanations are at play — different sources in our sample may have different origins.”

These results are not unique to M83. A follow-up study of the nearby star-forming galaxy M51 by Zoe Hoiland of Vassar College and Kilgard has uncovered a similar population of variable X-ray sources associated with supernova remnants, suggesting that such systems may be a feature of galaxies undergoing vigorous star formation.

This is a composite image of the galaxy M51 combining data from NASA's Chandra X-ray Observatory (purple) with optical data (red, green and blue) taken with ground-based telescopes by a team of astrophotographers. A surprisingly high number of X-ray sources associated with supernova remnants in M51 show large changes in brightness, similar to the behavior seen in M83.
This is a composite image of the galaxy M51 combining data from NASA’s Chandra X-ray Observatory (purple) with optical data (red, green and blue) taken with ground-based telescopes by a team of astrophotographers. A surprisingly high number of X-ray sources associated with supernova remnants in M51 show large changes in brightness, similar to the behavior seen in M83.
Chandra X-ray Data: NASA/CXC/SAO; Astrobin/Optical Groundbased: C.Björk, T.Bähnck, S.Donoso, J.Gentillon, A. and D.Grelin, S.Guberski, R. Hall, T.Heuberger, J.Jacks, P.Kent, Br.Meyers, W.Ostling, N.Puig, T.Schaeffer, F.Schöfbänker, M.Vasilev

The Chandra data for M83 began with single observations in 2000 and 2001, followed by 10 observations from 2010 to 2011 and another observation in 2014.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Visual Description

This release features a composite image of the nearby galaxy Messier 83, and short timelapse videos of two curious supernova remnants hidden inside.

In the composite image, Messier 83, or M83, is shown to have a spiral structure, viewed straight on. At the center is a brilliant white and yellow pool of light. From that light, spiral arms of hot pink cloud corkscrew out in wide, sweeping arches. The galaxy is covered in a faint grey haze, and flecked with red, green, blue, white, and yellow dots.

In an annotated version of the composite image, two tiny dots to our lower right of center are highlighted by white circles. These are two of the supernova remnants being considered by researchers. Each is examined further in a separate timelapse video.

Over a 14-year period from 2000 to 2014, astronomers pointed NASA’s X-ray observatory at the M83 galaxy. They discovered that about half of the X-ray sources believed to be supernova remnants, the aftermath of stellar explosions, were exhibiting dramatic changes in brightness. This result was entirely unexpected.

Those changes in brightness are highlighted in the timelapse videos. In each video, a series of static images flashes by, focused on one of the two X-ray sources once believed to be supernova remnants. In the videos, the X-ray sources appear as bright blue blobs with glowing cores. But in each image, taken months or years apart, the shapes change, as does the intensity of the blue color, and the brightness of the core. By presenting the substantively different images of the same objects one after another in quick succession, short timelapse videos are created.

The most likely explanation for the changes in brightness is that the team has uncovered a population of stellar survivors, stars that lived through an orbiting partner’s destruction in a supernova explosion. Material is being pulled from the surviving star onto the black hole or neutron star that formed in the supernova, a process known to cause rapid changes in X-ray brightness.

Read more from NASA’s Chandra X-ray Observatory

To learn more about NASA’s Chandra mission, visit:

https://science.nasa.gov/chandra

https://chandra.si.edu

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov

About the Author

Lee Mohon

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Last Updated
Jun 16, 2026
Editor
Lee Mohon
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Joel Wallace
Location
Marshall Space Flight Center

Amendment 59: Several Updates to the ROSES-25 Summary of Solicitation

15 June 2026 at 19:55

Research Opportunities in Space and Earth Sciences (ROSES)-2025 is an ongoing “omnibus” or “umbrella” solicitation meaning that it includes many individual program elements each with its own topics and due dates. Refer to Table 3 of ROSES-25 for a list of those program elements. The ROSES-25 “Summary of Solicitation” is the front matter that sets the default backstop rules for each of the program elements in ROSES-25.

ROSES-25 Amendment 59 makes several additions, changes, and clarifications to the ROSES-25 Summary of Solicitation to conform with Agency and administration priorities, see Sections I, I(g), II(a), II(b), III(b), III(d), V(b)ii, VI(c) & VIII(b). New text is in bold.

Important and substantial revisions to 2 CFR 200, the government-wide guidance for grants and cooperative agreements are proposed to take effect October 1, 2026, see https://www.federalregister.gov/documents/2026/05/29/2026-10817/regulation-for-federal-financial-assistance#h-8. Many types of currently allowable costs, such as but not limited to publications, research or events outside the United States, and domestic conferences may be restricted, denied, or may be allowable by legal exception or special award conditions only. Public comments on the revisions to 2 CFR 200 may be submitted until July 13, 2026, at https://www.regulations.gov/commenton/OMB-2026-0034-0001

On or about June 15, 2026, this Amendment to the NASA Research Announcement “Research Opportunities in Space and Earth Sciences (ROSES) 2025” (NNH25ZDA001N) will be posted on the NASA research opportunity homepage at https://solicitation.nasaprs.com/ROSES2025 and will appear on SARA’s ROSES blog at: https://science.nasa.gov/researchers/solicitations/roses-2025/

Questions concerning this amendment to ROSES-25 may be directed to SARA@nasa.gov.

The post Amendment 59: Several Updates to the ROSES-25 Summary of Solicitation appeared first on NASA Science.

NASA’s Chandra Finds Unexpected Fireworks in Aftermath of Stellar Explosions

15 June 2026 at 19:45
6 Min Read

NASA’s Chandra Finds Unexpected Fireworks in Aftermath of Stellar Explosions

A full field composite image of M83 with X-rays from Chandra (red, green, and blue) and optical light data from Hubble (red, green, and blue).
A composite image of the nearby galaxy Messier 83, and short timelapse videos of two curious supernova remnants hidden inside.
X-ray: NASA/CXC/SAO; Optical: NASA/ESA/AURA/STScI, Hubble Heritage Team, W. Blair (STScI/Johns Hopkins University) and R. O'Connell (University of Virginia); Image Processing: NASA/CXC/SAO/A. Jubett, L. Frattare and P. Edmonds

The aftermath of a supernova, a stellar explosion, is usually a slowly fading cloud of hot gas. So when astronomers pointed NASA’s Chandra X-ray Observatory at the nearby galaxy Messier 83 (M83), they did not expect to find a population of supernova remnants, or the debris from these explosions, showing dramatic changes in their brightness. The new results were presented at the American Astronomical Society meeting in Pasadena, California, and published in The Astrophysical Journal.

The galaxy M83, located about 15 million light-years from Earth, is forming stars at a high rate. Researchers analyzed 14 years of Chandra data of the galaxy, spanning 2000 to 2014.

Using this extensive set of data, the researchers caught surprising variations in the X-ray brightness of sources previously identified as supernova remnants. The researchers expected supernova remnants older than a century or so to fade gradually in X-rays, but not change dramatically in brightness.

The team found that roughly half of the 22 X-ray sources associated with supernova remnants in their sample showed changes in X-ray brightness over the 14-year span of observations — a result that was completely unexpected.

“We knew that individual X-ray sources could vary dramatically,” said Andrea Prestwich, of the Catholic University of America who led the study. “But finding that so many supernova remnants were behaving this way was a real surprise. Something unusual is going on in these objects. Pinpointing the cause remains a challenge, as M83’s distance limits the detail we can observe.”

One of the 22 variable supernova remnants has a straightforward explanation: SN 1957D, the debris from a supernova first observed nearly 70 years ago, is ramming into material surrounding the explosion site, producing the observed X-ray flares. But this cannot explain the rest of the sample. There is no evidence to suggest that all 22 remnants were formed within the last century. Something else must be driving the variability.

The most likely explanation is that the team has uncovered a population of stellar survivors stars that lived through their partner’s destruction in a supernova explosion. In this scenario, each variable X-ray source began as a pair of massive stars orbiting each other. The more massive star collapsed and exploded as a supernova, leaving behind a black hole or ultra-dense neutron star. Its companion survived.

A full field composite image of M83 with X-rays from Chandra (red, green, and blue) and optical light data from Hubble (red, green, and blue).
Galaxy M83 in X-ray and Optical Light.
X-ray: NASA/CXC/SAO; Optical: NASA/ESA/AURA/STScI, Hubble Heritage Team, W. Blair (STScI/Johns Hopkins University) and R. O’Connell (University of Virginia); Image Processing: NASA/CXC/SAO/A. Jubett, L. Frattare and P. Edmonds

“It may be that this galaxy contains a collection of supernova remnants where one massive star survives the supernova and becomes locked into an orbit with a black hole or neutron star,” said co-author Michael McCollough of the Center for Astrophysics | Harvard & Smithsonian (CfA). “The neutron star or black hole can then start pulling material from the massive star’s surface.”

That infalling material is superheated by the intense gravitational pull, producing the X-rays Chandra detects. These types of systems, known as high-mass X-ray binaries (HMXBs), are among the most variable X-ray sources in the universe. Researchers say they may be the cause of the variations seen in M83’s supernova remnants.

Astronomers have known about HMXBs for decades, but the difference with this group in M83 is their connection to supernova remnants. Previously, only a handful of supernova remnants associated with HMXBs had been identified across observations of all galaxies. It is unprecedented to find more than 20 strong candidates in just one galaxy.

The authors found that the variable supernova remnants are in regions with higher concentrations of massive stars than in other parts of the galaxy, increasing the chances of a link between the remnants and HMXBs.

There is another possible explanation: Instead of pulling in material from a companion star, the black hole or neutron star may be recapturing some of the material blasted outward by the original explosion.

“This could be an example of cosmic recycling, where debris from the explosion falls back onto the very object the supernova created,” said co-author Roy Kilgard of Wesleyan University. “And it’s quite possible that both explanations are at play — different sources in our sample may have different origins.”

These results are not unique to M83. A follow-up study of the nearby star-forming galaxy M51 by Zoe Hoiland of Vassar College and Kilgard has uncovered a similar population of variable X-ray sources associated with supernova remnants, suggesting that such systems may be a feature of galaxies undergoing vigorous star formation.

This is a composite image of the galaxy M51 combining data from NASA's Chandra X-ray Observatory (purple) with optical data (red, green and blue) taken with ground-based telescopes by a team of astrophotographers. A surprisingly high number of X-ray sources associated with supernova remnants in M51 show large changes in brightness, similar to the behavior seen in M83.
This is a composite image of the galaxy M51 combining data from NASA’s Chandra X-ray Observatory (purple) with optical data (red, green and blue) taken with ground-based telescopes by a team of astrophotographers. A surprisingly high number of X-ray sources associated with supernova remnants in M51 show large changes in brightness, similar to the behavior seen in M83.
Chandra X-ray Data: NASA/CXC/SAO; Astrobin/Optical Groundbased: C.Björk, T.Bähnck, S.Donoso, J.Gentillon, A. and D.Grelin, S.Guberski, R. Hall, T.Heuberger, J.Jacks, P.Kent, Br.Meyers, W.Ostling, N.Puig, T.Schaeffer, F.Schöfbänker, M.Vasilev

The Chandra data for M83 began with single observations in 2000 and 2001, followed by 10 observations from 2010 to 2011 and another observation in 2014.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Visual Description

This release features a composite image of the nearby galaxy Messier 83, and short timelapse videos of two curious supernova remnants hidden inside.

In the composite image, Messier 83, or M83, is shown to have a spiral structure, viewed straight on. At the center is a brilliant white and yellow pool of light. From that light, spiral arms of hot pink cloud corkscrew out in wide, sweeping arches. The galaxy is covered in a faint grey haze, and flecked with red, green, blue, white, and yellow dots.

In an annotated version of the composite image, two tiny dots to our lower right of center are highlighted by white circles. These are two of the supernova remnants being considered by researchers. Each is examined further in a separate timelapse video.

Over a 14-year period from 2000 to 2014, astronomers pointed NASA’s X-ray observatory at the M83 galaxy. They discovered that about half of the X-ray sources believed to be supernova remnants, the aftermath of stellar explosions, were exhibiting dramatic changes in brightness. This result was entirely unexpected.

Those changes in brightness are highlighted in the timelapse videos. In each video, a series of static images flashes by, focused on one of the two X-ray sources once believed to be supernova remnants. In the videos, the X-ray sources appear as bright blue blobs with glowing cores. But in each image, taken months or years apart, the shapes change, as does the intensity of the blue color, and the brightness of the core. By presenting the substantively different images of the same objects one after another in quick succession, short timelapse videos are created.

The most likely explanation for the changes in brightness is that the team has uncovered a population of stellar survivors, stars that lived through an orbiting partner’s destruction in a supernova explosion. Material is being pulled from the surviving star onto the black hole or neutron star that formed in the supernova, a process known to cause rapid changes in X-ray brightness.

Read more from NASA’s Chandra X-ray Observatory

To learn more about NASA’s Chandra mission, visit:

https://science.nasa.gov/chandra

https://chandra.si.edu

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov

About the Author

Lee Mohon

Share

Details

Last Updated
Jun 15, 2026
Editor
Lee Mohon
Contact
Joel Wallace
Location
Marshall Space Flight Center

The post NASA’s Chandra Finds Unexpected Fireworks in Aftermath of Stellar Explosions appeared first on NASA Science.

Rocket Attached to Aircraft for Katalyst-NASA Swift Boost

15 June 2026 at 18:23

A rocket attached to the belly of a large airplane
A Northrop Grumman Pegasus XL rocket is affixed to the bottom of the company’s Stargazer, a modified L-1011 aircraft, and ready for departure, as seen on June 12, 2026, at NASA’s Wallops Flight Facility in Virginia. Inside the rocket is Katalyst Space’s LINK robotic servicing spacecraft, which will launch to boost the orbit of NASA’s Neil Gehrels Swift Observatory.
NASA/Ron Beard

Engineers attached a Northrop Grumman Pegasus XL rocket to the company’s Stargazer aircraft at NASA’s Wallops Flight Facility in Virginia on Friday, June 12.

The rocket will carry LINK, a robotic servicing spacecraft from Katalyst Space, into orbit ahead of an attempt to boost NASA’s sinking Neil Gehrels Swift Observatory.

All spacecraft in low Earth orbit experience drag caused by our planet’s atmosphere, which gradually reduces their altitudes unless they have propulsion systems to counteract the effect.

A recent bout of solar activity magnified this effect on Swift, and its orbit has lowered faster than anticipated.

Katalyst selected Northrop Grumman’s Pegasus XL rocket as the best launch option for reaching the observatory in time for LINK to perform the boost procedure, based on the mission’s orbital and programmatic needs. Northrop Grumman will deploy the rocket using Stargazer, the company’s modified L-1011 airplane.

LINK will launch from Kwajalein Atoll, part of the Republic of the Marshall Islands in the South Pacific Ocean, later this month.

Learn more about the Swift boost:

https://science.nasa.gov/mission/swift/swift-boost-mission/

By Jeanette Kazmierczak
Goddard Space Flight Center, Greenbelt, Md.

The post Rocket Attached to Aircraft for Katalyst-NASA Swift Boost appeared first on NASA Science.

AI Learned the Rules of the Universe and That Became a Problem

14 June 2026 at 20:21
Quijote SimulationsAI could accelerate the hunt for new physics, but sometimes it knows too much to see what’s right in front of it. Artificial intelligence could make it much cheaper and faster to search for new laws of physics, according to a new study published in the Journal of Cosmology and Astroparticle Physics (JCAP). But the [...]

Scientists Develop a New Way To Measure Gravitational Waves in the Expanding Universe

14 June 2026 at 00:40
Astrophysics Gravitational Waves Spacetime VibrationsA new detector-based method clarifies how gravitational waves should be measured in an evolving universe. Imagine trying to measure a ripple on the surface of a pond while the pond itself is slowly changing shape. That is the challenge scientists face when they study gravitational waves not as isolated signals from colliding black holes, but [...]

Astronomers Find Strongest Evidence Yet for Magnetic Fields on Alien Worlds

By: ESO
12 June 2026 at 20:32
Artist’s Impression of an Exoplanet With a Magnetic FieldAstronomers studying the atmospheres of several intensely heated exoplanets uncovered an unexpected pattern that may reveal a hidden property of these distant worlds. Astronomers have uncovered the clearest evidence so far that some planets beyond our Solar System possess magnetic fields. By measuring atmospheric winds on seven extremely hot gas giants, researchers found signs that [...]

Astronomers Unveil Record-Breaking Haul of 161 New Black Hole Collisions

12 June 2026 at 19:57
Gravitational Waves IllustrationA new gravitational-wave catalogue reports 161 additional black hole mergers, bringing the total to 390 detections. Scientists at the University of Glasgow’s Institute for Gravitational Research are celebrating the release of a major new collection of gravitational wave discoveries, a milestone that highlights the rapid growth of gravitational astronomy. The latest Gravitational Wave Transient Catalogue [...]

Hubble Sees Swarm of Galaxies

12 June 2026 at 12:34

2 min read

Hubble Sees Swarm of Galaxies

Numerous galaxies dot the scene and appear to cluster around the image center. The view includes large elliptical galaxies along with spiral and lenticular galaxies. Faint arcs of distant galaxies gravitationally lensed by the cluster appear in the upper-right quadrant of the image. A couple of foreground stars are also visible and easily distinguished by their diffraction spikes.
This NASA Hubble Space Telescope image features the galaxy cluster MACS0329-0211.
NASA, ESA, M. Postman (STScI); Image Processing: G. Kober (NASA/Catholic University of America)

Looking somewhat like a swarm of bees returning to their hive, this NASA Hubble Space Telescope image features the galaxy cluster MACS0329-0211. Galaxy clusters like MACS0329-0211 are important signposts in the story of how the structure of the universe evolved, and are the ultimate telescopic lenses, placing gravitationally lensed galaxies from the earliest stages of the universe into our view.

Zoom into this galaxy swarm and you will find large, oval-shaped elliptical galaxies, and thin spiral and lenticular galaxies viewed from the edge. We can also see the full, face-on view of spiral galaxies and their curving spiral arms. The image’s upper-right quadrant holds faint arcs of distant galaxies gravitationally lensed by the cluster’s massive gravity. The largest of these arcs appears above the bright oval shape of a giant elliptical galaxy. Closer inspection of the image’s center reveals several bright-white intersecting curves that appear as a distorted figure eight. This may be another distant galaxy whose light was magnified and distorted by this massive cluster’s gravity.

Hubble looked at MACS0329-0211 as part of an observing program of X-ray bright galaxy clusters. Researchers used Hubble’s two main cameras, the Advanced Camera for Surveys and its Wide Field Camera 3, to gather data visible and infrared light from the cluster. Hubble’s ability to see such a broad spectrum of light makes it a valuable tool in understanding the very nature of these galaxy clusters.

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

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