Showing posts with label NASA's James Webb Space Telescope. Show all posts
Showing posts with label NASA's James Webb Space Telescope. Show all posts

Saturday, September 19, 2026

NASA’s Webb Reveals Dynamic Panorama of Star Formation

NASA’s James Webb Space Telescope recently observed IC 348, a star-forming region just 1,000 light-years away from Earth. Webb’s sharp vision revealed tiny brown dwarfs, some just twice Jupiter’s mass, and young stars ejecting powerful jets crashing into surrounding gas and dust.Credit Image: NASA, ESA, CSA, Kevin Luhman (PSU), Catarina Alves de Oliveira (ESA), Mahdi Zamani (ESA/Webb)

This collage features a collection of insets from NASA’s James Webb Space Telescope’s image of star-forming region IC 348: embedded stars, a central star cluster, faint outflows, Herbig-Haro objects, gravitational lensing, and spiral galaxies. Credit Image: NASA, ESA, CSA, Kevin Luhman (PSU), Catarina Alves de Oliveira (ESA), Mahdi Zamani (ESA/Webb)



This starry view of the nearby star-forming region IC 348 is one of the largest images released to date from NASA’s James Webb Space Telescope. Using Webb, astronomers searched IC 348 for brown dwarfs, which are less massive than the smallest stars. The researchers discovered brown dwarfs just twice the mass of Jupiter, bringing the study of these curious objects into a new mass range and revealing new insights about the star formation process.

The star-forming region IC 348 is located just 1,000 light-years away in the constellation Perseus. In regions like IC 348, cold clouds of molecular hydrogen gas collapse to form new stars, creating glowing, sculpted scenes like this one. The star-formation process can create widely varied objects, from massive stars that expire after only a few million years in core-collapse supernova explosions to the smallest and most common stars, which are long lived and produce powerful stellar storms.

The smallest stars weigh in at around 8 percent of the Sun’s mass. Below this mass lies a strange class of objects called brown dwarfs. Brown dwarfs form in the same way stars do, through the collapse of molecular clouds. However, unlike stars, the cores of brown dwarfs never become hot enough to fuse ordinary hydrogen into helium (though many briefly fuse deuterium, or heavy hydrogen, early in their lives).

What’s still not clear, and what researchers hoped to learn by using Webb’s sensitive instruments to study IC 348, is how small the smallest objects created by the star-formation process are. In other words, how small is the smallest brown dwarf?

Researchers seeking to answer this question first used Webb to study IC 348 in 2022, when they discovered brown dwarfs with masses as low as three to four times the mass of Jupiter. Now, the same research team has used Webb to probe even deeper into this region in search of even smaller brown dwarfs. The team used Webb’s NIRCam (Near-Infrared Camera) in 2024 to capture the warm glow of young brown dwarfs and newborn stars seen in this new image of IC 348. After selecting candidate brown dwarfs based on their colors and brightness, they followed up with Webb’s NIRSpec (Near-Infrared Spectrograph) in 2025 to conduct spectroscopic observations to study the masses of the brown dwarfs.

These deep Webb observations revealed something remarkable to the researchers: brown dwarfs with masses as low as just twice the mass of Jupiter or only 0.19 percent of the Sun’s mass — far smaller than theory predicts brown dwarfs should be. These are the least massive brown dwarfs known and their existence poses a challenge to models of how stars form.

In addition to the discovery of these unexpectedly lightweight brown dwarfs, the Webb observations contained even more surprises. One of the lightest newfound brown dwarfs showed signs of a disk, suggesting that small planets could be forming around an object that is itself only the mass of a planet.

While inspecting the spectra of IC 348’s brown dwarfs, the research team also found a feature they attributed to an unidentified hydrocarbon — molecules made only of hydrogen and carbon atoms. This specific feature has only been seen in the atmospheres of the lowest-mass brown dwarfs, suggesting that these extreme objects might exist in a spectral class of their own.

The stars and brown dwarfs of IC 348 aren’t the only attractions in this image. A brilliantly detailed collection of protostars occupies the upper right corner. Several of these protostars are accompanied by Herbig-Haro objects, which are luminous regions that form when jets from growing newborn stars crash into the gas and dust around the star.

The long, narrow feature that is oriented horizontally in this corner is the Herbig-Haro object HH 797. Upon close inspection, this source is revealed to be two protostars with nearly parallel outflows. Just to the right of HH 797 is the propeller-shaped source HH 211, which features both narrow jets and broader outflows.

The data used to create this image comes from the Webb General Observer Program 4866. In addition to studying the lowest-mass objects created through the star-formation process, this program also seeks to understand how the populations of planetary-mass objects like brown dwarfs vary between star-forming regions, as well as the origins of the hydrocarbon feature in the lowest-mass brown dwarfs.

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).




Details:

Last Updated: Sep 15, 2026
Location: NASA Goddard Space Flight Center


Contact Media:

Laura Betz

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

Bethany Downer
ESA/Webb
Baltimore, Maryland



Tuesday, August 11, 2026

Lion Nebula Roars to Life With NASA’s Webb

NASA’s James Webb Space Telescope imaged the planetary nebula NGC 2392, the Lion Nebula, using the observatory’s NIRCam and MIRI instruments. The central star’s remains are responsible for the nebula’s structure, including a lion face-shaped bubble of ionized gas and dust “mane.” Credit Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)

NASA’s James Webb Space Telescope’s mid-infrared image of planetary nebula NGC 2392, nicknamed the Lion Nebula, highlights the varying dust structures. Some dust is being destroyed by the dying central star’s radiation, while some dust filaments manage to survive. Credit Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)



Observing across the starry “plains” of space, NASA’s James Webb Space Telescope has taken new images of NGC 2392, nicknamed the Lion Nebula. NASA’s Hubble Space Telescope previously viewed this planetary nebula in 2000, imaging the lion face-shaped target in visible light and revealing features such as the “mane” of hazy, comet-shaped objects. Now Webb has captured a clearer, more detailed view of the Lion Nebula due to its high-resolution imaging.

At first glance the nebula’s overall structure in Webb’s infrared images, with both the NIRCam (Near Infrared Camera) and MIRI (Mid Infrared Instrument) instruments, may look quite similar to Hubble’s earlier visible-light view. However, Webb’s infrared vision highlights features like compact clumps of dust and a haze of ionized gas. It’s taken several thousand years for this collection of gas and dust to reach its current shape, and the nebula’s components continue to be altered.

The source of these constant changes and the reason for the Lion Nebula’s distinct appearance is located at the center: the remains of a dying star. Though it looks like the button nose of the lion, its energy and radiation are powering the intricate structures seen here.

Massive stars undergo supernova explosions at the end of their lives, but these kinds of events are few and far in between. Most of the universe’s stars have lower masses, like the one belonging to NGC 2392. When a lower-mass star can no longer sustain itself with nuclear reactions in its core, the star becomes unstable and pulsates, losing its mass by shedding its outer layers, which then turn into shells of gas and dust called a planetary nebula. (Stars at this life stage are responsible for producing much of the universe’s observable dust.) The star’s radiation drives the ejected material away, leaving behind the very hot stellar core, also known as a white dwarf.

In the Lion Nebula’s case, the death of the oxygen-rich central star has left behind a white dwarf that is “cooking” everything from the inside and producing a bubble of ionized gas as it does. The gas bubble, which forms the lion’s face, is expanding over time and destroying dust that is in its path. Understanding why the swept-up gas has a complex structure of rings and shells, a common feature in planetary nebulae, is an ongoing endeavor.

The mane of the lion is the interior of a dust shell that is being illuminated by the white dwarf at the center. The tufts of hair, which look like cometary tails of material, are compact clumps of dust that have survived the stellar core’s radiation and protect the material that lies behind them.

Webb’s imagery “freezes” this planetary nebula in time, though the star’s death, and its tumultuous effects, go on. NGC 2392 will continue to undergo changes as its gas and dust migrate away from the stellar core. Astronomers estimate the lion will eventually disperse in approximately 10,000 years — a relatively short period in astronomical terms.

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).




Details:

Last Updated: Aug 10, 2026
Location:
NASA Goddard Space Flight Center

Contact Media:

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland

laura.e.betz@nasa.gov

Abigail Major
Space Telescope Science Institute
Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland


Saturday, August 01, 2026

NASA Webb Explores Family Tree of Newly Discovered Distant Objects

Scientists have proposed one pathway little red dots can follow as the universe matures based on their analysis of spiral galaxy WISEA J123635.56+621424.2, nicknamed the “Saguaro.” They suggest little red dots may be a temporary phase of highly active supermassive black holes. Credit Image: NASA, ESA, CSA, STScI, Pierluigi Rinaldi (Steward Observatory); Image Processing: Alyssa Pagan (STScI)




Scientists synthetically shifted the Saguaro, a lower-redshift spiral galaxy, to a higher redshift to find out how it would appear if it was in the early universe. Its compact red appearance suggests that little red dots are a phase of highly active supermassive black holes. Credit Image: NASA, ESA, CSA, Pierluigi Rinaldi (Steward Observatory); Image Processing: Alyssa Pagan (STScI); Illustration: Leah Hustak (STScI)


Since their discovery by NASA’s James Webb Space Telescope in 2022, little red dots (LRDs) have been the subject of great interest to astronomers. Understanding the nature of these extremely distant, compact red sources has been a puzzling scientific endeavor.

One popular theory is that little red dots are supermassive black holes known as active galactic nuclei, although they display characteristics unlike nearby active galactic nuclei. While they appear abundant at high redshift early in the universe, they rapidly decrease in number at lower redshifts. (The higher the redshift, the greater the distance the light has traveled across the universe.) This perplexing shift in number raises the question: What happens to little red dots as the universe matures?

A team of researchers led by Pierluigi Rinaldi of the University of Arizona’s Steward Observatory, now at the Space Telescope Science Institute (STScI) in Baltimore, has built upon their previous research in a new study published on July 29 in The Astrophysical Journal and proposed one pathway LRDs can follow as the universe ages: Though they may look like a unique galaxy population, these dots are affected by observational bias — some features just don’t appear at higher redshifts with current technology.

Their conclusions are based on their analysis of lower-redshift spiral galaxy WISEA J123635.56+621424.2, nicknamed the “Saguaro” for its prominent arms, like the cactus native to the Sonoran Desert in the Southwestern United States. A particularly intriguing feature of this redshift 2 galaxy, which corresponds to approximately 3.3 billion years after the big bang, is its little red dot-like center that is reminiscent of the ruby red fruit produced by the desert plant.

“Everything created in the early universe must evolve into something around us. We have had little idea of what LRDs become, but these results finally show us how to find their progeny,” said co-author George Rieke of the University of Arizona. Previous studies by NASA’s retired Spitzer Space Telescope provided the first hint of the dust-obscured, compact galaxy population in the lower-redshift universe that the Saguaro belongs to, paving the way for NASA’s Hubble and James Webb space telescopes’ high-resolution analyses.

“The Saguaro is important because it’s a prototypical little red dot and is one of the few we have found at lower redshift. It can be used to study the pathway of these dots throughout cosmic time,” said Fabio Pacucci of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and a co-author of the study.

Among the thousands of sources Rinaldi looked at across several surveys, the Saguaro was an example of the right place — with one of Webb’s microshutter arrays perfectly framed over the galaxy’s core to take spectroscopic data — and right time — being at lower redshift. To get as broad a view of the spiral galaxy as possible across the electromagnetic spectrum, the team used Hubble’s ultraviolet- and Webb’s infrared-imaging and spectroscopic archival data, respectively.

“Because the Saguaro is at lower redshift, we can see the very beautiful and bright host galaxy in high resolution and detail with Webb and Hubble,” said Zihao Wu of the Harvard-Smithsonian Center for Astrophysics, and a co-author of the study. “Webb’s observations can help us understand how the galaxy and its little red dot-like nucleus are connected.”

The team took multiple approaches to verify that the Saguaro’s compact red nucleus matched the characteristics of a prototypical LRD. In particular, the Hubble and Webb data showed that the nucleus is brighter in both ultraviolet and infrared light than in visible light, just like distant LRDs. The team also carefully disentangled the light emitted from the host and nucleus, and considered the presence of X-ray emission from the source.

Although the majority of little red dots at high redshift are not detectable in X-ray light, NASA’s Chandra X-ray Observatory detected weak X-ray emission from the Saguaro.

“What the X-ray light observations show is that this galaxy has an active galactic nucleus, and a very obscured one at that,” said Carys Gilbert, a Master’s student at the University of Cape Town in South Africa and a co-author of the paper. “It’s not only obscured but also X-ray weak. That kind of combination could explain the lack of X-ray emission that we see from all other little red dots. It fits the puzzle of little red dots nicely.”

In addition to demonstrating how the Saguaro’s central compact red source fits the little red dot criteria, the team synthetically shifted the galaxy to a higher redshift to explore how this galactic environment would appear to observers if located in the early universe. As expected, the Saguaro’s surrounding galactic structure fades so that only the bright, LRD-like source at its center is visible.

“Our theory is that most of these distant sources are affected by this cosmological effect, creating an observational bias,” said Rinaldi. “We simply are not able to sample the immediate environment of high-redshift little red dots because their surroundings are just too faint to be observed even with Webb. Little red dots are far more complex than just being a dot. They’re just the tip of the iceberg — of a supermassive black hole interacting with its nearby surroundings.”

Considering the Saguaro case study, the team believes that LRDs may not be a unique galaxy population, but instead a temporary phase of highly active supermassive black holes. Could this theory be the link between the populous high-redshift little red dots seen by Webb and the local universe?c While the Saguaro is not representative of all LRDs, the team proposes that this is one phase of these compact red sources. To build more confidence, further study of the Saguaro is necessary, as well as seeking other Saguaro-like galaxies at lower redshift. The team also intends to comb through Webb’s bountiful archival data to build a census of little red dots to study how their environments may impact how they mature. These different approaches are all geared to helping uncover the family tree of little red dots.

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.




Details:

Last Updated: Jul 29, 2026
Location:
NASA Goddard Space Flight Center

Contact Media:

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland

laura.e.betz@nasa.gov

Abigail Major
Space Telescope Science Institute
Baltimore, Maryland


Hannah Braun
Space Telescope Science Institute
Baltimore, Maryland



Thursday, July 23, 2026

NASA’s Webb Discovers Hidden Planet in Famous Star System

This artist’s concept shows the Beta Pictoris system with the discovered giant exoplanet Beta Pictoris d at the right. It has the widest orbit of the known three exoplanets within the system. Credit Illustration: NASA, ESA, CSA, STScI, Ralf Crawford (STScI)

Researchers used the NIRSpec (Near-Infrared Spectrograph) Integral Field Unit on NASA’s James Webb Space Telescope to map chemical contents of the Beta Pictoris system. As a result, they discovered a third planet, Beta Pictoris d, orbiting the young star. Credid Image: NASA, ESA, CSA, STScI, Leah Hustak (STScI); Science: Aidan Gibbs (UC San Diego), Jean-Baptiste Ruffio (UC San Diego), Alexis Bidot (STScI); Image Processing: Alyssa Pagan (STScI)

The newly discovered third planet orbiting Beta Pictoris, Beta Pictoris d, is seen in reconstructed imagery from NASA’s James Webb Space Telescope’s NIRSpec (Near-Infrared Spectrograph). Credit Image: NASA, ESA, CSA, STScI; Science: Aidan Gibbs (UC San Diego), Jean-Baptiste Ruffio (UC San Diego); Image Processing: Alyssa Pagan (STScI)



Astronomers using NASA's James Webb Space Telescope have discovered a giant planet outside our solar system, called an exoplanet, hiding within one of the most intensely studied planetary systems in our Milky Way galaxy.

The young, nearby star Beta Pictoris was already known to host two giant planets: Beta Pictoris b, one of the first exoplanets ever directly imaged, and Beta Pictoris c. The newly identified Beta Pictoris d makes it only the second planetary system known to contain at least three imaged planets. Unlike Beta Pictoris b and c, however, Beta Pictoris d was discovered not by identifying a bright point of light, but by detecting the unique chemical fingerprint of its atmosphere, a technique that could transform the search for worlds around other stars.

"This discovery adds another piece to an already fascinating planetary system," said Aidan Gibbs, lead author of a new study published Wednesday in the Astrophysical Journal Letters and a postdoctoral researcher at the University of California, San Diego. "Beta Pictoris has long served as a laboratory for understanding how planetary systems form and evolve, and now we have another planet helping us tell that story."

Familiar system, new surprise

Located 63 light-years from Earth and about 23 million years old, Beta Pictoris is a nearby system in the Milky Way offering a rare glimpse of the interactions between newborn planets and the disk of dust and debris left behind from their formation.

The team estimates that the newfound Beta Pictoris d is likely at least two times the mass of Jupiter, making it the smallest of the three known giant planets in the system. Modeling suggests it likely circles around its star at about 30 astronomical units, comparable to the region occupied by Neptune in our own solar system. It’s the widest orbit of the known three planets, but still located inside the inner edge of the debris disk.

Although astronomers were not searching for another planet with Webb, Beta Pictoris d emerged while the team was using the telescope’s NIRSpec (Near-Infrared Spectrograph) to study the atmosphere of Beta Pictoris b. Specifically, they used NIRSpec’s Integral Field Unit, which obtains both an image and a spectrum from each pixel in an image.

"We weren't looking for a new planet," said Gibbs. "We were trying to understand one we already knew existed. Then, this telltale signal appeared in the data where we didn’t expect it."

This signal was a series of peaks and troughs within the spectroscopic data where the team expected to see a smooth spectrum from light bouncing off dust. It was a distinctive pattern of carbon monoxide absorption lines, spread out like a barcode, an expected feature in giant planet atmospheres.

Because spectroscopy not only reveals chemical composition, but the motion of an object, the team was able to also extract radial velocity from the data. The team determined the planet’s speed, position, and alignment with the debris disk were all consistent with something orbiting Beta Pictoris rather than a background star or brown dwarf with carbon monoxide in its atmosphere.

"There was an unexpected bright source of light within the Integral Field Unit imaging, but we've learned not to trust bright blobs in images," said Jean-Baptiste Ruffio, a research scientist at University of California, San Diego and principal investigator of the first Webb observations where the discovery was made. "They can be instrumental artifacts or other structures in the debris disk. By obtaining a spectrum at the same time as the image, we were able to quickly confirm our suspicions.”

Follow-up observations with Webb's MIRI (Mid-Infrared Instrument) through a Director’s Discretionary Time request detected water vapor and methane, further confirming the planet's identity while providing a richer look at the atmosphere of the planet.

Unlike traditional imaging, the spectroscopic approach allowed researchers to identify the planet and begin studying its atmosphere from the very first observation.

"A spectrum contains an incredible amount of information," Ruffio said. "You don't just learn that something is a planet; you immediately begin learning about its temperature, chemistry, and motion."

A separate imaging study led by Ben Sutlieff of the University of Edinburgh and Markus Bonse of the European Southern Observatory complements the team’s findings with data from the European Southern Observatory’s Very Large Telescope and Webb’s NIRCam (Near-Infrared Camera) and independently confirmed the existence of Beta Pictoris d.

Seeing through cosmic fog

Beta Pictoris d remained hidden for years because it lies within one of the brightest debris disks known.

The dusty disk acts like fog, scattering light from the star, making it difficult for conventional imaging techniques to distinguish planets from surrounding structures. The team's spectroscopic method with Webb effectively ignored that dust, isolating only the narrow molecular signatures unique to a planetary atmosphere.

Scientists say the planet’s presence may help explain why the famous debris disk has such a sharply defined inner edge and other puzzling structures. In fact, astronomers had already predicted the existence of a planet like Beta Pictoris d to account for the disk’s unusual structure.

Beyond expanding our understanding of Beta Pictoris, the discovery demonstrates a powerful new way to find exoplanets.

This is the first directly imaged planet discovered primarily through moderate-resolution spectroscopy, showing that astronomers can identify worlds in complex environments through their atmospheric fingerprints rather than relying solely on traditional coronagraphic imaging.

The researchers plan to continue analyzing Webb's observations to better determine the planet's temperature, atmospheric composition, and orbit, providing an even more detailed view of one of astronomy's most iconic planetary systems.

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).




Details:

Last Updated: Jul 15, 2026
Location:
NASA Goddard Space Flight Center

Contact Media:

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland

laura.e.betz@nasa.gov


Friday, July 03, 2026

NASA’s Webb Reveals Stars Sparking to Life in Cosmic Celebration

In infrared light, NASA’s James Webb Space Telescope reveals bright protostars in star system FS Tau and a tapestry of background galaxies. FS Tau B, the orange protostar slightly right of center, is thought to be responsible for the orange outflows amid the dusty region. Credit Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)

A comparison between the observations of FS Tau by NASA’s Hubble and James Webb space telescopes. Hubble’s visible-light view shows the star-forming region mostly obscured by thick dust. Webb sees through the dust, revealing how the protostars are shaping their surroundings. Credit Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)

An image of FS Tau captured by Webb’s NIRCam (Near-Infrared Camera), with compass arrows, scale bar, and color key for reference. Credit Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)



NASA’s James Webb Space Telescope has captured the infrared light of numerous features that previously were impossible to see beyond the thick dust of the FS Tau star system. In addition to myriad background galaxies that burst into view like fireworks for the United States’ 250th anniversary celebrations, this image flickers with a number of protostars, or baby stars that are formed from dense pockets of gas and dust. These hot, clumpy, and low-mass objects eventually will become full-fledged stars capable of burning hydrogen in their cores, like our Sun. The protostars of FS Tau are about 1 to 3 million years old, which is relatively young in cosmic scales. Our Sun, by contrast, is 4.6 billion years old.

Low-mass stars emit less radiation and have less energetic stellar winds than those with larger masses, which means they disrupt their environment at a much lower level. This makes the FS Tau region incredibly useful for studying low-mass star evolution without the same level of environmental interference seen near higher-mass stars. A pair of protostars that creates the largest diffraction pattern seen slightly to the left of center in the image, called FS Tau A, is about half the mass of our Sun.

Even though these objects are young and low-mass, they still can impact their surroundings, partially due to the outflows they emit. These outflows, seen as orange and red wisps and wide sheets, are theorized to come from FS Tau B, the protostar slightly to the right of center that has an orange diffraction pattern. As FS Tau B feeds on the surrounding dust and gas to grow, it ejects some of that matter outward. The wider outflows are thought to come from the interaction between the protostar’s magnetic field and superheated matter closest to the protostar within its accretion disk. The disk is seen as a dark band that cuts across at a 30-degree angle.

The gaps between the outflows, newly discovered in this Webb observation, add to growing evidence that protostars accrete matter in discrete episodes. In the periods where protostars gather material and increase in mass, they also eject superheated matter in different directions. In between these episodes, they are relatively quiet.

As protostars eject these outflows, they shape their surroundings. This is best shown by the prominent light-blue ridges of dust and gas near FS Tau B. These thicker regions were likely created as outflows struck and compressed matter together. The brightness of these light-blue ridges shows that the nearby protostar’s light is reflected. Moreover, Webb’s sensitivity reveals the varying textures of dust and gas across the entire region.

The range of colors seen in this observation also provides a wealth of information, specifically about where dust is and how much of it obscures the region. Light with bluer wavelengths is absorbed and scattered by dust, while redder-wavelength light is able to slip through. Therefore, background galaxies behind thicker foreground dust appear redder. Alternatively, yellow galaxies have much less dust obscuring them. The few white stars visible in this image are likely in the foreground.

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).




Details:

Last Updated: Jul 02, 2026
Location:
NASA Goddard Space Flight Center

Contact Media:

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland

laura.e.betz@nasa.gov

Matthew Brown
Space Telescope Science Institute
Baltimore, Maryland


Abigail Major
Space Telescope Science Institute
Baltimore, Maryland



Thursday, July 02, 2026

NASA’s Webb Studies How Planet Survived Death of its Star

Exoplanet WD 1856 b, shown in this artist’s concept, is a gas giant that orbits its star at a distance 50 times closer than Earth orbits the Sun. Observations by NASA’s James Webb Space Telescope determined the planet’s temperature and detected molecules in its atmosphere. Credit Artwork: NASA, ESA, CSA, Ralf Crawford (STScI)

NASA’s James Webb Space Telescope measured the constituents of exoplanet WD 1856 b as it passed in front of its star, finding signs of methane. WD 1856 b orbits a white dwarf star the size of Earth. As a result, the planet blocks more than half of the star’s light. Credit Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)



NASA’s James Webb Space Telescope is giving us new insight into the far-future of solar systems like our own, as the agency continues to reveal the secrets of the universe and our place in it. Billions of years ago, a Sun-like star nearing the end of its life swelled tremendously in size to become a red giant before ejecting its outer layers, leaving a hot, remnant core known as a white dwarf. As a red giant, the star should have engulfed and destroyed any nearby planets. Yet astronomers have found a Jupiter-sized exoplanet orbiting the white dwarf every 34 hours at a separation of less than 2 million miles (3 million kilometers).

To solve the mystery of how this exoplanet survived, an international team of astronomers used NASA’s James Webb Space Telescope to watch the Jupiter-sized exoplanet WD 1856 b transit its host star, measuring the planet’s temperature and detecting molecules in its atmosphere. They found the planet is significantly warmer than expected and determined how it most likely reached its very tight orbit around the white dwarf star. The results are a window into the future of planets like Jupiter after the death of the Sun, billions of years into the future.

The results published Wednesday in the journal Nature.

WD 1856 b was discovered in 2020 by scientists using NASA’s TESS (Transiting Exoplanet Survey Satellite) and the retired Spitzer Space Telescope. It orbits the white dwarf WD 1856+534, which is located about 80 light-years from Earth. “The planet is about the size of Jupiter, but the white dwarf it orbits is the size of Earth, so the planet is seven times larger than its star," said lead author Ryan MacDonald of the University of St. Andrews in the United Kingdom.

WD 1856 b orbits extremely close to its host star, a distance 50 times closer than Earth orbits the Sun. If WD 1856 b had originally been orbiting at that distance, it would have been obliterated while the star was a red giant. How did it survive the death of its host star and end up in its current position?

How big, how hot

The new study used Webb to watch the planet passing in front of its star. This transit yielded unique information about the planet’s mass, which is between four and eleven times the mass of Jupiter.

The team also was able to determine the planet’s temperature. During the transit, light from the star was partly blocked, but infrared light was reduced less than other wavelengths. The difference was infrared light emitted by the planet from its own heat. The data indicated that the planet has a temperature of about 260 degrees Fahrenheit (126 degrees Celsius) — significantly hotter than it would be if its only source of heat was the light from the white dwarf. This puzzling discovery turned out to be the key fact that proved how the planet must have reached its current orbit.

Christopher O’Connor of Northwestern University in Illinois, a co-author on the paper, was responsible for tracing the temperature of the planet back in time. O’Connor said, “The big question is how WD 1856 b ended up where it is today, and there are two theories. One is that the planet was swallowed by the host star as it was dying, and managed to survive on the inside. The other is that migration took place due to the gravitational effect of other objects in the system. The white dwarf is part of a triple star system, and the companion stars could have influenced WD 1856 b’s orbit.”

The researchers realized that there was no source of energy present to generate that heat today, so it must be residual energy from an earlier time when the planet was heated. Using models of how sub-stellar objects like WD 1856 b cool down over time, coupled with the new data from Webb, the team was able to project its temperature back in time and deduce how long ago the heating must have happened. The timing is key to determining whether the heating was from being engulfed by the red giant or occurred during an inward migration.

They concluded that the heating most likely happened between 3 and 5.5 billion years after the star became a white dwarf. In this scenario, the planet was on a wide orbit that kept it safe from the star during its destructive red giant phase, and only migrated to its present location later on. “As the planet moved inward, its interactions with the strong gravity of the white dwarf will have caused it to warm up considerably, and it has been cooling ever since,” said O’Connor.

Light from the star passing through the planet’s atmosphere also picked up information about its chemical composition. “We saw the telltale signatures of small cloud particles and hydrocarbons, most likely methane, which is the first time we have seen an atmosphere on a planet transiting a dead star,” said co-author Victoria Boehm of Cornell University. “We recently observed four more transits of WD 1856 b with Webb to take a deeper look into its atmospheric chemistry and can’t wait to see the results.”

Solar system’s possible future

In approximately five billion years, the Sun will run out of hydrogen fuel in its core and swell up more than 100 times larger than it is now into a red giant star. It will then shed its outer layers and end its life as a white dwarf star. Mercury, Venus, and possibly the Earth will be destroyed by the red giant. However, the fate of the more distant planets, particularly the gas giants, is unclear. Finding and studying planets in orbit around the remnants of Sun-like stars after their death is a means of learning what might happen in our own solar system in the far future.

“We’re used to looking back in time when we use telescopes, but this is the first time we have been able to look forward to what might happen to the outer planets around the remnant of a Sun-like star,” said MacDonald. “It’s like using a time machine to peer into the distant future of our solar system.”

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).




Details:

Last Updated: Jul 01, 2026
Location:
NASA Goddard Space Flight Center

Contact Media:

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland

laura.e.betz@nasa.gov

Bethany Downer
ESA/Webb
Baltimore, Maryland
Christine Pulliam Space Telescope Science Institute Baltimore, Maryland



Saturday, June 27, 2026

NASA’s Webb Pinpoints Millions of Stars Within Cigar Galaxy

Scientists used NASA’s James Webb Space Telescope to image edge-on starburst galaxy Messier 82 and trace its evolutionary history. This Webb and Hubble composite image includes 16.5 million stars (blue-white), dust grains (red-orange), and ionized hydrogen gas (yellow). Credit Image: NASA, ESA, CSA, Adam Smercina (STScI, Tufts), Thomas Williams (University of Manchester); Image Processing: Alyssa Pagan (STScI)

NASA’s James Webb Space Telescope observed edge-on starburst galaxy Messier 82, peering through dust to reveal 16.5 million stars and the galaxy’s distended disk structure. Scientists seek to learn the galaxy’s evolutionary history with the Webb data. Credit Image: NASA, ESA, CSA, Adam Smercina (STScI, Tufts), Thomas Williams (University of Manchester); Image Processing: Alyssa Pagan (STScI)

Side-by-side comparison of a portion of starburst galaxy Messier 82 (M82) as seen by NASA’s Hubble (left) and James Webb (right) space telescopes. Hubble detailed M82’s gas and dust structure, while Webb pierced through the dust and resolved millions of stars in infrared light. Credit Image: NASA, ESA, CSA, Adam Smercina (STScI, Tufts), Thomas Williams (University of Manchester); Image Processing: Alyssa Pagan (STScI)

Annotated image of the starburst galaxy Messier 82 captured by Webb's NIRCam (Near-Infrared Camera) instrument, with compass arrows, a scale bar, and color key for reference. Credit Image: NASA, ESA, CSA, Adam Smercina (STScI, Tufts), Thomas Williams (University of Manchester); Image Processing: Alyssa Pagan (STScI)

NASA’s James Webb Space Telescope’s near-infrared observation of M82 is the most recent addition to overall data on this starburst galaxy. The Hubble Space Telescope is one observatory that has previously looked at M82, detailing the gas and dust structure seen in visible light. Credit Video: NASA, ESA, CSA, STScI, Alyssa Pagan (STScI)



Located 12 million light-years away and undergoing rapid star formation, edge-on spiral galaxy Messier 82 (M82) is a scientifically unique sight to behold, and now NASA’s James Webb Space Telescope has revealed previously unseen details.

M82’s intense star formation, thought to be the result of a galaxy merger, will be a short-lived event in astronomical terms, estimated to last a few hundred million years in its entirety. This temporary phase of extreme star formation relative to the galaxy’s mass, as well as its location in the local universe, are among the factors that make M82, also known as the Cigar galaxy, a one-of-a-kind environment to study.

A team of astronomers recently completed an imaging survey with the Webb telescope. This program entailed a total of 65 hours of observation time with Webb’s NIRCam (Near-Infrared Camera) instrument and revealed never-seen-before details of the starburst galaxy, including its distended disk structure and millions of individual stars. Webb’s high-resolution imaging, specifically of the main plane of the galactic disk, has unlocked vital information for astronomers as they seek to uncover M82’s formation history. Additionally, the Webb data will help scientists understand the current processes occurring within the starburst galaxy.

“M82 is a mess, but it’s a beautiful mess. We don’t fully understand what’s going on, especially concerning its evolutionary history. What could have triggered such an elevated rate of star formation? How long has this galaxy been driving plumes of material away from its center?” said principal investigator Adam Smercina, a NASA Hubble Fellow at the Space Telescope Science Institute in Baltimore, and incoming Assistant Professor at Tufts University in Massachusetts. “M82 is an ideal galaxy evolution laboratory because it has properties that allow us to probe important physical processes, such as how stars form in such environments and how that activity drives outflows. M82 provides a simultaneous window onto many astrophysical questions, in a way that no other galaxy in the local universe can.”

Prior to Webb, many observatories looked at the starburst galaxy, including NASA’s Hubble and retired Spitzer space telescopes. However, the sheer volume of dust within that galaxy limited the amount of information astronomers could acquire on M82 at high resolution. While Webb has previously looked at this galaxy, the duration of the new imaging survey, combined with the telescope’s infrared sensitivity, enabled it to pierce through the thick dust.

The telescope’s near-infrared-light view is a snapshot of a scene that has been evolving over a couple hundred million years. Webb’s image contains approximately 16.5 million individual stars dispersed throughout the galaxy. The light from these stellar sources is depicted as luminous blue granules. This is only a small portion of the total amount of stars astronomers think reside in a galaxy like M82, with the majority too faint to be seen.

“The sheer number of stars that we were able to resolve with Webb is incredible,” said team member Benjamin Williams of the University of Washington. “It’s a whole different world from what we’ve been able to see with other telescopes. All of these stars collectively provide a detailed fossil record of the formation and evolution of M82.”

Moving inward, the increase in brightness and the asymmetrical shape of the galactic disk hints at the spiral galaxy’s unique underlying structure. The differing radii between the two sides suggests that M82 has a distorted shape, which can happen during intense galaxy mergers.

“At first glance, the disk of the galaxy may seem less spectacular because Webb sees through the dust,” said team member Eric Bell of the University of Michigan. “But M82 is a delightfully complex system. Webb’s observations will help us address some ongoing mysteries, such as how star formation has moved within M82 over the last few billion years.”

Because of the extreme star formation within the galaxy, which is 10 times faster than the Milky Way galaxy’s star formation rate, stellar birth will eventually be disrupted. M82’s stellar frenzy is causing bipolar plumes of material to be ejected above and below the disk. Though it looks like a tumultuous region, the hourglass-shaped outflows appear to have a layered structure. The yellow tendrils of material closest to the galaxy’s disk represent ionized gas, whereas the orange material farther away depicts small dust grains. These grains are called polycyclic aromatic hydrocarbons and are helpful in tracing material in the space between the galaxy’s stars, also known as the interstellar medium.

The information collected as part of this Webb study is just one dataset scientists will analyze as they seek to piece together this starburst galaxy’s formation history.

“Galaxies are such intricate ecosystems that if you truly want to understand them, you have to pull datasets from different missions together,” said team member Kristen McQuinn of the Space Telescope Science Institute. “One mission cannot fully answer all of the questions we have about M82. Combining the data collected by different telescopes, like Webb and Hubble, is powerful. When you marry the datasets, you expand what you can probe, and the questions that you can pose are even more complex.”

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).




Details:

Last Updated: Jun 23, 2026
Location:
NASA Goddard Space Flight Center

Contact Media:

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland

laura.e.betz@nasa.gov

Abigail Major
Space Telescope Science Institute
Baltimore, Maryland


Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland



Friday, June 26, 2026

NASA’s Webb Finds Clues to Ancient, Distant Origin of Comet 3I/ATLAS

Researchers used the NIRSpec (Near-Infrared Spectrograph) instrument on NASA’s James Webb Space Telescope to map specific chemical contents of comet 3I/ATLAS as it moved away from the Sun. Credit Image: NASA, ESA, CSA, STScI, Martin Cordiner (CUA, NASA-GSFC); Image Processing: Alyssa Pagan (STScI)

These graphs lay out the significant difference in composition between the interstellar comet 3I/ATLAS and comets originating in our solar system. This very specific data helps researchers build a picture of the comet’s original planetary system. Credit Illustration: NASA, ESA, CSA, Martin Cordiner (CUA, NASA-GSFC), Leah Hustak (STScI)



As interstellar comet 3I/ATLAS began moving away from the Sun in December 2025, astronomers took the opportunity to turn NASA’s powerful James Webb Space Telescope in its direction and capture detailed measurements of its chemical components. The comet was freshly warmed from its closest pass by the Sun, and its ancient ice had been converted to a bright coma of gas ideal for observation.

Webb captured detailed data, including chemical ratios of carbon and deuterium, also known as heavy hydrogen, that are not found in solar system comets. The results surprised researchers. Working backward, astronomers used the components that make up comet 3I/ATLAS to understand the environment in which it formed.

A paper detailing the findings published June 22 in the journal Nature.

The comet’s name comes from its status as the third confirmed interstellar comet, meaning it originated outside the solar system, and the telescope that first spotted it, the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System).

“This was a unique opportunity to study an ancient object from the distant galaxy, probably pre-dating our Sun and solar system,” said astro-chemist Martin Cordiner of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study. “On the one hand, we get direct insight into that distant time and place, and on the other, we learn something about how unusual our own solar system may be.”

Cordiner and the research team joined astronomers from many sub-disciplines in taking the opportunity to get a look at 3I/ATLAS on its journey through the solar system. They received approval to interrupt Webb’s planned schedule of observations to make use of its NIRSpec (Near-Infrared Spectrograph) instrument to study the comet.

NIRSpec revealed exceptionally high levels of deuterium, about 30 times more than seen in solar system comets. This implies that 3I/ATLAS may have originated in a very cold system much earlier in the history of our galaxy. During its formation, the material that became incorporated into 3I/ATLAS was likely exposed to plenty of radiation, but not any long-term warmth that would have reprocessed its “heavy water” ice, with deuterium, into the type of H2O ice we are familiar with on Earth.

Additionally, NIRSpec showed only traces of carbon-13 compared to lighter-weight carbon-12. This also points to a very old origin for 3I/ATLAS, as stellar systems become enriched with carbon-13 over time as generations of stars are born and die in the galaxy. That is why there are higher levels of carbon-13 in our system, around our Sun, which formed relatively recently, 4.5 billion years ago.

The research team estimates that 3I/ATLAS could have formed as long as 10 to 12 billion years ago, during the universe’s “cosmic noon,” when star formation was at its height. Its young origin system was likely ensconced in a relatively cold, dense cloud. The abundance of heavy water shows that 3I/ATLAS spent its formative years in a deeply frozen state.

A separate study using the European Southern Observatory's Very Large Telescope, led by astronomer Cyrielle Opitom of the University of Edinburgh, complements Webb’s findings with an analysis of 3I/ATLAS’s carbon and nitrogen varieties in the form of the chemical cyanide. “For us as scientists, finding these rare isotopes is fascinating, but the bigger picture here is looking at the possibilities of prebiotic chemistry elsewhere in the galaxy,” said Stefanie Milam of NASA Goddard and co-author of the study with Cordiner. “So far, we know of only one place in the vast cosmos where chemical ingredients led to life – our solar system, our Earth. Analysis of these interstellar objects is a major step towards learning how common, or uncommon, the conditions for the evolution of life are in the universe.”

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).




Details:

Last Updated:: Jun 22, 2026
Location::
NASA Goddard Space Flight Center

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


Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland



Saturday, June 20, 2026

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

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)



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.

“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).




Details:

Last Updated: Jun 16, 2026
Location:
NASA Goddard Space Flight Center

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



Wednesday, June 17, 2026

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

New observations from Webb combined with multiple observations from Hubble prove that Terzan 5 is a self-contained, self-enriching stellar system that contains up to four distinct star populations. It orbits within our Milky Way galaxy’s central bulge.Credit Image: NASA, ESA, CSA, STScI, Giorgia Zullo (University of Bologna), Francesco Ferraro (University of Bologna); Image Processing: Alyssa Pagan (STScI)

Yhis 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 color key for reference. The scale bar is labeled in light-years along the bottom, which is the distance that light travels in one Earth-year. (It takes two years for light to travel a distance equal to the length of the scale bar.) One light-year is equal to about 5.88 trillion miles or 9.46 trillion kilometers. The north and east compass arrows show the orientation of the image on the sky. Note that the relations hip between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above). This image shows visible and near-infrared wavelengths of light that have been translated into visible-light colors. The color key shows which NIRCam and ACS filters were used when collecting the light. The color of each filter name is the visible-light color used to represent the infrared light that passes through that filter. Credit Image: NASA, ESA, CSA, STScI, Giorgia Zullo (University of Bologna), Francesco Ferraro (University of Bologna); Image Processing: Alyssa Pagan (STScI)

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. The Milky Way is shaped like a giant fried egg. The yolk in the middle is the galactic bulge, a crowded region packed with ancient stars of various masses and brightnesses. It’s also home to a number of globular star clusters that formed early in our galaxy’s history, which typically have only one ancient star population. In contrast, Terzan 5 was recently reclassified as a bulge fossil fragment because it has four generations of stars and has maintained its separate identity. Credit Video: NASA, ESA, CSA, Alyssa Pagan (STScI); Acknowledgment: ESO, Pan-STARRS, DSS2, Akira Fujii



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.

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.




Details:

Last Updated: Jun 16, 2026
Location:
NASA Goddard Space Flight Center

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