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Webb watches Wolf-Rayet 140: carbon-rich dust shells form, expand in star system

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A three-part graphic showing observations of Wolf-Rayet 140, two massive stars with 17 dust shells around them. An inset appears at right, showing a portion of the two observations matched up to show that the arced dust has moved.

Webb watches Wolf-Rayet 140: carbon-rich dust shells form, expand in star system

Astronomers using the NASA/ESA/CSA James Webb Space Telescope have identified two stars responsible for generating carbon-rich dust a mere 5000 light-years away in our own Milky Way galaxy. As the massive stars in Wolf-Rayet 140 swing past one another on their elongated orbits, their winds collide and produce the carbon-rich dust. For a few months every eight years, the stars form a new shell of dust that expands outward — and may eventually go on to become part of stars that form elsewhere in our galaxy.

Astronomers have long tried to track down how elements like carbon, which is essential for life, become widely distributed across the Universe. Now, the James Webb Space Telescope has examined one ongoing source of carbon-rich dust in our own Milky Way galaxy in greater detail: Wolf-Rayet 140 [1], a system of two massive stars that follow a tight, elongated orbit.

As they swing past one another (within the central white dot in the Webb images), the stellar winds from each star slam together, the material compresses, and carbon-rich dust forms. Webb’s latest observations show 17 dust shells shining in mid-infrared light that are expanding at regular intervals into the surrounding space.

“The telescope confirmed that these dust shells are real, and its data also showed that the dust shells are moving outward at consistent velocities, revealing visible changes over incredibly short periods of time,”

said Emma Lieb, the lead author of the new paper and a doctoral student at the University of Denver in Colorado.

Every shell is racing away from the stars at more than 2600 kilometres per second, almost 1% the speed of light. 

“We are used to thinking about events in space taking place slowly, over millions or billions of years,” added Jennifer Hoffman, a co-author and a professor at the University of Denver. “In this system, the observatory is showing that the dust shells are expanding from one year to the next.”

“Seeing the real-time movement of these shells between Webb’s observations that were taken only 13 months apart is truly remarkable,” said Olivia Jones, a co-author at the UK Astronomy Technology Centre, Edinburgh. “These new results are giving us a first glimpse of the potential role of such massive binaries as factories of dust in the Universe.”

Like clockwork, the stars’ winds generate dust for several months every eight years, as the pair make their closest approach during a wide, elongated orbit. Webb also shows where dust formation stops — look for the darker region at top left in both images.

The telescope’s mid-infrared images detected shells that have persisted for more than 130 years (older shells have dissipated enough that they are now too dim to detect). The researchers speculate that the stars will ultimately generate tens of thousands of dust shells over hundreds of thousands of years.

“Mid-infrared observations are absolutely crucial for this analysis, since the dust in this system is fairly cool. Near-infrared and visible-light observations would only show the shells that are closest to the star,” explained Ryan Lau, a co-author and astronomer at NSF NOIRLab in Tucson, Arizona, who led the initial research about this system. “With these incredible new details, the telescope is also allowing us to study exactly when the stars are forming dust — almost to the day.”

The distribution of the dust isn’t uniform. Though these differences aren’t obvious in Webb’s images, the team found that some of the dust has ‘piled up’, forming amorphous, delicate clouds that are as large as our entire Solar System. Many other individual dust particles float freely. Every speck is as small as one-hundredth the width of a human hair. Clumpy or not, all of the dust moves at the same speed and is carbon rich.

The future of this system

What will happen to these stars over millions or billions of years, after they have finished ‘spraying’ their surroundings with dust? The Wolf-Rayet star in this system is 10 times more massive than the Sun and nearing the end of its life. In its final ‘act’, this star will either explode as a supernova — possibly blasting away some or all of the dust shells — or collapse into a black hole, which would leave the dust shells intact.

Though no one can predict with any certainty what will happen, researchers are rooting for the black hole scenario.

“A major question in astronomy is, where does all the dust in the universe come from?” Lau said. “If carbon-rich dust like this survives, it could help us begin to answer that question.”

“We know carbon is necessary for the formation of rocky planets and solar systems like ours,” Hoffman added. “It’s exciting to get a glimpse into how binary star systems not only create carbon-rich dust, but also propel it into our galactic neighborhood.”

These results have been published in the Astrophysical Journal Letters and were presented in a press conference at the 245th meeting of the American Astronomical Society in National Harbor, Maryland.

Notes

[1] A Wolf-Rayet star is born with at least 25 times more mass than our Sun and is nearing the end of its life, when it will likely collapse directly to black hole, or explode as a supernova. Burning hotter than in its youth, a Wolf-Rayet star generates powerful winds that push huge amounts of gas into space. The Wolf-Rayet star in this particular pair may have shed more than half its original mass via this process.

 

Press release from ESA Webb.

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Massive black hole in the early universe is lying dormant in its host galaxy, GN-1001830

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JWST buco nero dormiente GN-1001830

Massive black hole in the early universe spotted taking a ‘nap’ after overeating, and lying dormant in its host galaxy, GN-1001830

JWST buco nero dormiente GN-1001830 Illustrazione artistica che rappresenta l'aspetto potenziale del buco nero supermassiccio scoperto dal team di ricerca durante la sua fase di intensa attività super-Eddington. Crediti: Jiarong Gu
A study in Nature finds that black holes in the early Universe go through short periods of ultra-fast growth, followed by long periods of dormancy. Picture credits: Jiarong Gu

Scientists have spotted a massive black hole in the early universe that is ‘napping’ after stuffing itself with too much food.

Like a bear gorging itself on salmon before hibernating for the winter, or a much-needed nap after Christmas dinner, this black hole has overeaten to the point that it is lying dormant in its host galaxy, GN-1001830.

An international team of astronomers, led by the University of Cambridge, used the NASA/ESA/CSA James Webb Space Telescope to detect this black hole in the early universe, just 800 million years after the Big Bang.

The black hole is huge – 400 million times the mass of our Sun – making it one of the most massive black holes discovered by Webb at this point in the universe’s development. The black hole is so enormous that it makes up roughly 40% of the total mass of its host galaxy: in comparison, most black holes in the local universe are roughly 0.1% of their host galaxy mass.

However, despite its gigantic size, this black hole is eating, or accreting, the gas it needs to grow at a very low rate – about 100 times below its theoretical maximum limit – making it essentially dormant.

Such an over-massive black hole so early in the universe, but one that isn’t growing, challenges existing models of how black holes develop. However, the researchers say that the most likely scenario is that black holes go through short periods of ultra-fast growth, followed by long periods of dormancy. Their results are reported in the journal Nature.

When black holes are ‘napping’, they are far less luminous, making them more difficult to spot, even with highly-sensitive telescopes such as Webb. Black holes cannot be directly observed, but instead they are detected by the tell-tale glow of a swirling accretion disc, which forms near the black hole’s edges. The gas in the accretion disc becomes extremely hot and starts to glow and radiate energy in the ultraviolet range.

“Even though this black hole is dormant, its enormous size made it possible for us to detect,” said lead author Ignas Juodžbalis from Cambridge’s Kavli Institute for Cosmology. “Its dormant state allowed us to learn about the mass of the host galaxy as well. The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

According to standard models, black holes form from the collapsed remnants of dead stars and accrete matter up to a predicted limit, known as the Eddington limit, where the pressure of radiation on matter overcomes the gravitational pull of the black hole. However, the sheer size of this black hole suggests that standard models may not adequately explain how these monsters form and grow.

“It’s possible that black holes are ‘born big’, which could explain why Webb has spotted huge black holes in the early universe,” said co-author Professor Roberto Maiolino, from the Kavli Institute and Cambridge’s Cavendish Laboratory. “But another possibility is they go through periods of hyperactivity, followed by long periods of dormancy.”

Working with colleagues from Italy, the Cambridge researchers conducted a range of computer simulations to model how this dormant black hole could have grown to such a massive size so early in the universe. They found that the most likely scenario is that black holes can exceed the Eddington limit for short periods, during which they grow very rapidly, followed by long periods of inactivity: the researchers say that black holes such as this one likely eat for five to ten million years, and sleep for about 100 million years.

“It sounds counterintuitive to explain a dormant black hole with periods of hyperactivity, but these short bursts allow it to grow quickly while spending most of its time napping,” said Maiolino.

Because the periods of dormancy are much longer than the periods of ultra-fast growth, it is in these periods that astronomers are most likely to detect black holes.

“This was the first result I had as part of my PhD, and it took me a little while to appreciate just how remarkable it was,” said Juodžbalis. “It wasn’t until I started speaking with my colleagues on the theoretical side of astronomy that I was able to see the true significance of this black hole.”

Due to their low luminosities, dormant black holes are more challenging for astronomers to detect, but the researchers say this black hole is almost certainly the tip of a much larger iceberg, if black holes in the early universe spend most of their time in a dormant state.

“It’s likely that the vast majority of black holes out there are in this dormant state – I’m surprised we found this one, but I’m excited to think that there are so many more we could find,” said Maiolino.

The observations were obtained as part of the JWST Advanced Deep Extragalactic Survey (JADES). The research was supported in part by the European Research Council and the Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI).

 

Bibliographic Information:

“A dormant, overmassive black hole in the early Universe”, by Ignas Juodžbalis, Roberto Maiolino, William M. Baker, Sandro Tacchella, Jan Scholtz, Francesco D’Eugenio, Raffaella Schneider, Alessandro Trinca, Rosa Valiante, Christa DeCoursey, Mirko Curti, Stefano Carniani, Jacopo Chevallard, Anna de Graaff, Santiago Arribas, Jake S. Bennett, Martin A. Bourne, Andrew J. Bunker, Stephane Charlot, Brian Jiang, Sophie Koudmani, Michele Perna, Brant Robertson, Debora Sijacki, Hannah Ubler, Christina C. Williams, Chris Willott, Joris Witstok, has been published on Nature (18-Dec-2024).

Press release from the University of Cambridge

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By observing NGC 346, Webb finds planet-forming discs lived longer in early Universe

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NGC 346 planet-forming discs The center of the image contains arcs of orange and pink that form a boat-like shape. One end of these arcs points to the top right of the image, while the other end point toward the bottom left. Another plume of orange and pink expands from the center to the top left of the image. To the right of this plume is a large cluster of white stars. There are various other white stars and a few galaxies of different sizes spread throughout the image. Ten, small, yellow circles overlaid at various points across the image indicate the positions of the ten stars surveyed in this study.

By observing NGC 346, Webb finds planet-forming discs lived longer in early Universe: new data refutes current theories of planet formation in Universe’s early days

 

The NASA/ESA/CSA James Webb Space Telescope just solved a conundrum by proving a controversial finding made with the NASA/ESA Hubble Space Telescope more than 20 years ago.

This image features NGC 346, one of the most dynamic star-forming regions in nearby galaxies, as seen by the NASA/ESA/CSA James Webb Space Telescope.
NCG 346 is located in the Small Magellanic Cloud (SMC), a dwarf galaxy close to our Milky Way.
Credit: NASA, ESA, CSA, STScI, A. Pagan (STScI)

In 2003, Hubble provided evidence of a massive planet around a very old star, almost as old as the Universe. Such stars possess only small amounts of heavier elements that are the building blocks of planets. This implied that some planet formation happened when our Universe was very young, and those planets had time to form and grow big inside their primordial discs, even bigger than Jupiter. But how? This was puzzling.

A side-by-side comparison of a Hubble image of the massive star cluster NGC 346 (left) versus a Webb image of the same cluster (right). The Hubble image shows the cluster in shades of blue against a black background punctuated by white stars of various sizes. Ethereal nebulosity, looking much like draped chiffon, dominates the image. The Webb view, in shades of pink and orange against a black background, is speckled with fewer stars than in the Hubble version. These stars are white and pink. Webb pierces through the cluster’s clouds to reveal more of its structure, which looks like twisted fibers.
This side-by-side comparison shows a Hubble image of the massive star cluster NGC 346 (left) versus a Webb image of the same cluster (right). While the Hubble image shows more nebulosity, the Webb image pierces through those clouds to reveal more of the cluster’s structure. NGC 346 has a relative lack of elements heavier than helium and hydrogen, making it a good proxy for stellar environments in the early, distant universe.
Credit: NASA, ESA, CSA, STScI, O. C. Jones (UK ATC), G. De Marchi (ESTEC), M. Meixner (USRA), A. Nota (ESA)

To answer this question, researchers used Webb to study stars in a nearby galaxy that, much like the early Universe, lacks large amounts of heavy elements. They found that not only do some stars there have planet-forming discs, but that those discs are longer-lived than those seen around young stars in our Milky Way galaxy.

“With Webb, we have a really strong confirmation of what we saw with Hubble, and we must rethink how we model planet formation and early evolution in the young Universe,” said study leader Guido De Marchi of ESA’s European Space Research and Technology Centre in Noordwijk, Netherlands.

A different environment in early times

In the early Universe, stars formed from mostly hydrogen and helium, and very few heavier elements such as carbon and iron, which came later through supernova explosions.

“Current models predict that with so few heavier elements, the discs around stars have a short lifetime, so short in fact that planets cannot grow big,” said the Webb study’s co-investigator Elena Sabbi, chief scientist for Gemini Observatory at the National Science Foundation’s NOIRLab in Tucson. “But Hubble did see those planets, so what if the models were not correct and discs could live longer?”

To test this idea, scientists trained Webb on the Small Magellanic Cloud, a dwarf galaxy that is one of the Milky Way’s nearest neighbors. In particular, they examined the massive, star-forming cluster NGC 346, which also has a relative lack of heavier elements. The cluster served as a nearby proxy for studying stellar environments with similar conditions in the early, distant Universe.

The center of the image contains arcs of orange and pink that form a boat-like shape. One end of these arcs points to the top right of the image, while the other end point toward the bottom left. Another plume of orange and pink expands from the center to the top left of the image. To the right of this plume is a large cluster of white stars. There are various other white stars and a few galaxies of different sizes spread throughout the image. Ten, small, yellow circles overlaid at various points across the image indicate the positions of the ten stars surveyed in this study.
This is a NASA/ESA/CSA James Webb Space Telescope image of NGC 346, a massive star cluster in the Small Magellanic Cloud, a dwarf galaxy that is one of the Milky Way’s nearest neighbors. With its relative lack of elements heavier than helium and hydrogen, the NGC 346 cluster serves as a nearby proxy for studying stellar environments with similar conditions in the early, distant Universe. Ten, small, yellow circles overlaid on the image indicate the positions of the ten stars surveyed in this study.
Credit: NASA, ESA, CSA, STScI, O. C. Jones (UK ATC), G. De Marchi (ESTEC), M. Meixner (USRA)

Hubble observations of NGC 346 from the mid 2000s revealed many stars about 20 to 30 million years old that seemed to still have planet-forming discs around them. This went against the conventional belief that such discs would dissipate after 2 or 3 million years.

“The Hubble findings were controversial, going against not only empirical evidence in our galaxy but also against the current models,” said De Marchi. “This was intriguing, but without a way to obtain spectra of those stars, we could not really establish whether we were witnessing genuine accretion and the presence of discs, or just some artificial effects.”

Now, thanks to Webb’s sensitivity and resolution, scientists have the first-ever spectra of forming, Sun-like stars and their immediate environments in a nearby galaxy.

“We see that these stars are indeed surrounded by discs and are still in the process of gobbling material, even at the relatively old age of 20 or 30 million years,” said De Marchi. “This also implies that planets have more time to form and grow around these stars than in nearby star-forming regions in our own galaxy.”

By observing NGC 346, Webb finds planet-forming discs lived longer in early Universe: new data refutes current theories of planet formation in Universe’s early days. This image features NGC 346, one of the most dynamic star-forming regions in nearby galaxies, as seen by the NASA/ESA/CSA James Webb Space Telescope.
NCG 346 is located in the Small Magellanic Cloud (SMC), a dwarf galaxy close to our Milky Way.
Credit: NASA, ESA, CSA, STScI, A Pagan (STScI)

A New Way of Thinking

This finding refutes previous theoretical predictions that when there are very few heavier elements in the gas around the disc, the star would very quickly blow away the disc. So the disc’s life would be very short, even less than a million years. But if a disc doesn’t stay around the star long enough for the dust grains to stick together and pebbles to form and become the core of a planet, how can planets form?

The researchers explained that there could be two distinct mechanisms, or even a combination, for planet-forming discs to persist in environments scarce in heavier elements.

First, to be able to blow away the disc, the star applies radiation pressure. For this pressure to be effective, elements heavier than hydrogen and helium would have to reside in the gas. But the massive star cluster NGC 346 only has about ten percent of the heavier elements that are present in the chemical composition of our Sun. Perhaps it simply takes longer for a star in this cluster to disperse its disc.

The second possibility is that, for a Sun-like star to form when there are few heavier elements, it would have to start from a larger cloud of gas. A bigger gas cloud will produce a bigger disc. So there is more mass in the disc and therefore it would take longer to blow the disc away, even if the radiation pressure were working in the same way.

“With more matter around the stars, the accretion lasts for a longer time,” said Sabbi. “The discs take ten times longer to disappear. This has implications for how you form a planet, and the type of system architecture that you can have in these different environments. This is so exciting.”

The science team’s paper appears in the 16 December 2024 issue of The Astrophysical Journal.

planet-forming discs Graphic titled Star in NGC 346, Molecular Hydrogen in Protoplanetary Disk, NIRSpec Microshutter Array Spectroscopy showing brightness of 2.02- to 2.37-micron light of a star and its environment (plotted in yellow) and a star’s environment only (plotted in pink) on an xy graph of brightness versus wavelength in microns. Two wavelength bands, ranging from 2.05 to 2.07 and 2.16 to 2.18, are highlighted in red and labeled Hot Atomic Helium, He. A band from 2.11 to 2.13 in blue is labeled Cold Molecular Hydrogen, H 2. The spectrum of the star plus environment (yellow) has prominent peaks at 2.06 and 2.17 microns (He), and at 2.12 microns (H). The spectrum of the star’s environment only (pink) also has peaks at 2.06 and 2.17 microns (He), but not at 2.12 (H). The two spectra are offset vertically for readability. An inset shows them plotted with the same vertical alignment: the helium peaks on the star plus environment spectrum are slightly taller than those of the environment only.
This graph shows, on the bottom left in yellow, a spectrum of one of the 10 target stars in this study (as well as accompanying light from the immediate background environment). Spectral fingerprints of hot atomic helium, cold molecular hydrogen, and hot atomic hydrogen are highlighted. On the top left in magenta is a spectrum slightly offset from the star that includes only light from the background environment. This second spectrum lacks a spectral line of cold molecular hydrogen.
On the right is the comparison of the top and bottom lines. This comparison shows a large peak in the cold molecular hydrogen coming from the star but not its nebular environment. Also, atomic hydrogen shows a larger peak from the star. This indicates the presence of a protoplanetary disc immediately surrounding the star. The data was taken with the microshutter array on the James Webb Space Telescope’s NIRSpec (Near-Infrared Spectrometer) instrument.
Credit: NASA, ESA, CSA, J. Olmsted (STScI)

Press release from ESA Webb

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Firefly Sparkle Found: first actively forming galaxy as lightweight as young Milky Way

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Horizontal split down the middle. At left, thousands of overlapping objects at various distances are spread across this galaxy cluster. A box at bottom right is enlarged on the right half. A central oval identifies the Firefly Sparkle galaxy, a line with 10 dots in various colours.

Firefly Sparkle Found: first actively forming galaxy as lightweight as young Milky Way

For the first time, the NASA/ESA/CSA James Webb Space Telescope has detected and ‘weighed’ a galaxy that not only existed around 600 million years after the Big Bang, but also has a mass that is similar to what our Milky Way galaxy’s mass might have been at the same stage of development. Other galaxies Webb has detected at this period in the history of the Universe are significantly more massive. Nicknamed the Firefly Sparkle, this galaxy is gleaming with star clusters — 10 in all — each of which researchers examined in great detail.

“I didn’t think it would be possible to resolve a galaxy that existed so early in the Universe into so many distinct components, let alone find that its mass is similar to our own galaxy’s when it was in the process of forming,” said Lamiya Mowla, co-lead author of the paper and an assistant professor at Wellesley College in Massachusetts. “There is so much going on inside this tiny galaxy, including so many different phases of star formation.”

Thousands of overlapping objects at various distances are spread across this field, including galaxies in a massive galaxy cluster, and distorted background galaxies behind the galaxy cluster. The background of space is black.
Thousands of glimmering galaxies are bound together by their own gravity, making up a massive cluster formally classified as MACS J1423.
The largest bright white oval is a supergiant elliptical galaxy that is the dominant member of this galaxy cluster. The galaxy cluster acts like a lens, magnifying and distorting the light from objects that lie well behind it, an effect known as gravitational lensing that has big research benefits. Astronomers can study lensed galaxies in detail, like the Firefly Sparkle galaxy.
This 2023 image is from the James Webb Space Telescope’s NIRCam (Near-InfraRed Camera). Researchers used Webb to survey the same field that the Hubble Space Telescope imaged in 2010. Thanks to its specialisation in high-resolution near-infrared imagery, Webb was able to show researchers many more galaxies in far more detail.
Credit: NASA, ESA, CSA, STScI, C. Willott (NRC-Canada), L. Mowla (Wellesley College), K. Iyer (Columbia)

Webb was able to image the galaxy in sufficient detail for two reasons. One is a benefit of the cosmos: a massive foreground galaxy cluster radically enhanced the distant galaxy’s appearance through a natural effect known as gravitational lensing. And when combined with the telescope’s specialisation in high-resolution imaging of infrared light, Webb delivered unprecedented new data about the galaxy’s contents.

“Without the benefit of this gravitational lens, we would not be able to resolve this galaxy,” said Kartheik Iyer, co-lead author and NASA Hubble Fellow at Columbia University in New York. “We knew to expect it based on current physics, but it’s surprising that we actually saw it.”

Mowla, who spotted the galaxy in Webb’s image, was drawn to its gleaming star clusters, because objects that sparkle typically indicate they are extremely clumpy and complicated. Since the galaxy looks like a ‘sparkle’ or swarm of fireflies on a warm summer night, they named it the Firefly Sparkle galaxy.

Reconstructing the galaxy’s appearance

The research team modelled what the galaxy might have looked like if its image weren’t stretched by gravitational lensing and discovered that it resembled an elongated raindrop. Suspended within it are two star clusters toward the top and eight toward the bottom.

“Our reconstruction shows that clumps of actively forming stars are surrounded by diffuse light from other unresolved stars,” said Iyer. “This galaxy is literally in the process of assembling.”

Webb’s data show the Firefly Sparkle galaxy is on the smaller side, falling into the category of a low-mass galaxy. Billions of years will pass before it builds its full heft and a distinct shape. “Most of the other galaxies Webb has shown us aren’t magnified or stretched, and we are not able to see their ‘building blocks’ separately. With Firefly Sparkle, we are witnessing a galaxy being assembled brick by brick,” Mowla said.

Stretched out and shining, ready for close analysis

Since the image of the galaxy is warped into a long arc, the researchers easily picked out 10 distinct star clusters, which are emitting the bulk of the galaxy’s light. They are represented here in shades of pink, purple, and blue. Those colours in Webb’s images and its supporting spectra confirmed that star formation didn’t happen all at once in this galaxy, but was staggered in time.

“This galaxy has a diverse population of star clusters, and it is remarkable that we can see them separately at such an early age of the Universe,” said Chris Willott of the National Research Council Canada, a co-author and the observation programme’s principal investigator. “Each clump of stars is undergoing a different phase of formation or evolution.”

The galaxy’s projected shape shows that its stars haven’t settled into a central bulge or a thin, flattened disc, another piece of evidence that the galaxy is still forming.

Horizontal split down the middle. At left, thousands of overlapping objects at various distances are spread across this galaxy cluster. A box at bottom right is enlarged on the right half. A central oval identifies the Firefly Sparkle galaxy, a line with 10 dots in various colours.
For the first time, astronomers have identified a still-forming galaxy that weighs about the same as our Milky Way if we could wind back the clock to see our galaxy as it developed. The newly identified galaxy, the Firefly Sparkle, is in the process of assembling and forming stars, and existed about 600 million years after the Big Bang.
The image of the galaxy is stretched and warped by a natural effect known as gravitational lensing, which allowed researchers to glean far more information about its contents. (In some areas of Webb’s image, the galaxy is magnified over 40 times.)
While it took shape, the galaxy gleamed with star clusters in a range of infrared colours, which are scientifically meaningful. They indicate that the stars formed at different periods, not all at once.
Since the galaxy image is stretched into a long line in Webb’s observations, researchers were able to identify 10 distinct star clusters and study them individually, along with the cocoon of diffuse light from the additional, unresolved stars surrounding them. That’s not always possible for distant galaxies that aren’t lensed. Instead, in many cases researchers can only draw conclusions that apply to an entire galaxy. “Most of the other galaxies Webb has shown us aren’t magnified or stretched and we are not able to see the ‘building blocks’ separately. With Firefly Sparkle, we are witnessing a galaxy being assembled brick by brick,” explains astronomer Lamiya Mowla.
There are two companion galaxies ‘hovering’ close by, which may ultimately affect how this galaxy forms and builds mass over billions of years. Firefly Sparkle is only about 6500 light-years away from its first companion, and 42 000 light-years from its second companion. Let’s compare these figures to objects that are closer to home: the Sun is about 26 000 light-years from the centre of our Milky Way galaxy, and the Milky Way is about 100 000 light-years across. Not only are Firefly Sparkle’s companions very close, the researchers also suspect that they are orbiting one another.
Credit: NASA, ESA, CSA, STScI, C. Willott (NRC-Canada), L. Mowla (Wellesley College), K. Iyer (Columbia)

‘Glowing’ companions

Researchers can’t predict how this disorganised galaxy will build up and take shape over billions of years, but there are two galaxies that the team confirmed are ‘hanging out’ within a tight perimeter and may influence how it builds mass over billions of years.

Firefly Sparkle is only 6500 light-years away from its first companion, and its second companion is separated by 42 000 light-years. For context, the fully formed Milky Way is about 100 000 light-years across — all three would fit inside it. Not only are its companions very close, the researchers also think that they are orbiting one another.

Each time one galaxy passes another, gas condenses and cools, allowing new stars to form in clumps, adding to the galaxies’ masses. 

“It has long been predicted that galaxies in the early Universe form through successive interactions and mergers with other tinier galaxies,” said Yoshihisa Asada, a co-author and doctoral student at Kyoto University in Japan. “We might be witnessing this process in action.”

“This is just the first of many such galaxies JWST will discover, as we are only starting to use these cosmic microscopes”, added team member Maruša Bradač of the University of Ljubljana in Slovenia. “Just like microscopes let us see pollen grains from plants, the incredible resolution of Webb and the magnifying power of gravitational lensing let us see the small pieces inside galaxies. Our team is now analysing all early galaxies, and the results are all pointing in the same direction: we have yet to learn much more about how those early galaxies formed.”

The team’s research relied on data from Webb’s CAnadian NIRISS Unbiased Cluster Survey, which include near-infrared images from NIRCam (Near-InfraRed Camera) and spectra from the microshutter array aboard NIRSpec (Near-Infrared Spectrograph). The CANUCS data intentionally covered a field that NASA’s Hubble Space Telescope imaged as part of its Cluster Lensing And Supernova survey with Hubble programme.

This work was published on 12 December 2024 in the journal Nature.

A graphic labelled “James Webb Space Telescope; MACS J1423.8+2404.” A rectangular image shows thousands of galaxies of various shapes and colours on the black background of space.
Thousands of glimmering galaxies are bound together by their own gravity, making up a massive cluster formally classified as MACS J1423.
The largest bright white oval is a supergiant elliptical galaxy that is the dominant member of this galaxy cluster. The galaxy cluster acts like a lens, magnifying and distorting the light from objects that lie well behind it, an effect known as gravitational lensing that has big research benefits. Astronomers can study lensed galaxies in detail, like the Firefly Sparkle galaxy.
This 2023 image is from the James Webb Space Telescope’s NIRCam (Near-Infrared Camera). Researchers used Webb to survey the same field the Hubble Space Telescope imaged in 2010. Thanks to its specialisation in high-resolution near-infrared imagery, Webb was able to show researchers many more galaxies in far more detail.
The north and east compass arrows show the orientation of the image on the sky.
The scale bar is labelled in arcseconds, which is a measure of angular distance on the sky. One arcsecond is equal to an angular measurement of 1/3600 of one degree. There are 60 arcminutes in a degree and 60 arcseconds in an arcminute. (The full Moon has an angular diameter of about 30 arcminutes.) The actual size of an object that covers one arcsecond on the sky depends on its distance from the telescope.
This image shows invisible near-infrared wavelengths of light that have been translated into visible-light colours. The colour key shows which NIRCam filters were used when collecting the light. The colour of each filter name is the visible light colour used to represent the infrared light that passes through that filter.
NIRCam filters from left to right: F115W and F150W are blue; F200W and F277W are green; F356W and F444W are red.
Credit: NASA, ESA, CSA, STScI, C. Willott (NRC-Canada), L. Mowla (Wellesley College), K. Iyer (Columbia)

Press release from ESA Webb

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Hubble celebrates a decade of tracking the outer planets

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A montage of Hubble Space Telescope images of our solar system’s four giant outer planets: Jupiter, Saturn, Uranus, and Neptune, taken under the OPAL (Outer Planet Atmospheres Legacy) program over a duration of 10 years, from 2014 to 2024.

Hubble celebrates a decade of tracking the outer planets

From 2014 to 2024, the NASA/ESA Hubble Space Telescope has been studying the outer planets under a program called OPAL (Outer Planet Atmospheres Legacy) to obtain long-time baseline observations of Jupiter, Saturn, Uranus, and Neptune in order to understand their atmospheric dynamics and evolution. Hubble is the only telescope that can provide high spatial resolution and image stability for global studies of cloud coloration, activity, and atmospheric motion on a consistent time basis to help constrain the underlying mechanics of weather and climate systems.

All four of the outer planets have deep atmospheres and no solid surfaces. Their churning atmospheres have their own unique weather systems, some with colorful bands of multicolored clouds, and with mysterious, large storms that pop up or linger for many years. Each also has seasons lasting many years as they revolve around the Sun.

Following the complex behavior is akin to understanding Earth’s dynamic weather as followed over many years, as well as the Sun’s influence on the solar system’s weather. The four wonder-worlds also serve as proxies for understanding the weather and climate on similar planets orbiting other stars.

Planetary scientists realized that any one year of data from Hubble, while interesting in its own right, doesn’t tell you the full story on the outer planets. Hubble’s OPAL program has routinely visited the planets once a year when they are closest to the Earth, an alignment called opposition. This has yielded a huge archive of data that has led to a string of remarkable discoveries to share with planetary astronomers around the world.

Highlights of the OPAL team’s decade of discovery is provided below.

Jupiter

Jupiter’s bands of clouds present an ever-changing kaleidoscope of shapes and colors. There is always stormy weather on Jupiter: cyclones, anticyclones, wind shear, and the largest storm in the solar system, the Great Red Spot (GRS). Jupiter is covered with largely ammonia ice-crystal clouds on top of an atmosphere that’s tens of thousands of miles deep.

Hubble’s sharp images track clouds and measure the winds, storms, and vortices, in addition to monitoring the size, shape and behavior of the GRS. Hubble follows as the GRS continues shrinking in size, but is still large enough to swallow Earth. OPAL data recently measured how often mysterious dark ovals—visible only at ultraviolet wavelengths—appeared in the “polar hoods” of stratospheric haze. Unlike Earth, Jupiter is only inclined three degrees on its axis (Earth is 23.5 degrees). Seasonal changes might not be expected, except that Jupiter’s distance from the Sun varies by roughly 64 million kilometres over its 12-year-long orbit, and so OPAL closely monitors the atmosphere for seasonal effects. Another Hubble advantage is that ground-based observatories can’t continuously view Jupiter for two Jupiter rotations, because that adds up to 20 hours. During that time, an observatory on the ground would have gone into daytime and Jupiter would no longer be visible until the next evening.

A two-panel image labeled “Jupiter, January 5, 2024, HST WFC3/UVIS” showcases the wealth of information provided by the spectral filters on the Hubble’s Wide Field Camera 3 (WFC3) science instrument. At left, this Hubble image of Jupiter is created using three filters at wavelengths similar to the colors seen by the human eye: F395N is blue, F502N is green, F658N is red. At right, the wavelength bounds are widened beyond the visible range to extend just into the ultraviolet (UV) and infrared regimes: F343N is blue, F467M is green, FQ889N is red. Humans can’t perceive these extended wavelengths. The result is a vivid disk that shows UV-absorbing lofty hazes as orange (over the poles and in three large storms, including the Great Red Spot), and freshely-formed ice as white (compact storm plumes just north of the equator). These filters (and others not shown here) allow astronomers to study differences in cloud thickness, altitude, and chemical makeup.
Two views of Jupiter showcase the wealth of information provided by the spectral filters on the Hubble Space Telescope’s Wide Field Camera 3 (WFC3) science instrument. At left, the RGB composite is created using three filters at wavelengths similar to the colors seen by the human eye. At right, the wavelength bounds are widened beyond the visible range to extend just into the ultraviolet (UV) and infrared regimes. Humans cannot perceive these extended wavelengths, but some animals are able to detect infrared and ultraviolet light. The result is a vivid disk that shows UV-absorbing lofty hazes as orange (over the poles and in three large storms, including the Great Red Spot), and freshly-formed ice as white (compact storm plumes just north of the equator). Astronomers, including the OPAL team, use these filters (and others not shown here) to study differences in cloud thickness, altitude, and chemical makeup.
Credit: NASA, ESA, A. Simon (NASA/GSFC), M. Wong (UC Berkeley), J. DePasquale (STScI)

OPAL’s findings may also support ESA’s Jupiter Icy Moons Explorer, Juice, which was launched on 14 April 2023. Juice will make detailed observations of Jupiter and its three large ocean-bearing moons — Ganymede, Callisto and Europa — with a suite of remote sensing, geophysical and in situ instruments. The mission will characterise these moons as both planetary objects and possible habitats, explore Jupiter’s complex environment in depth, and study the wider Jupiter system as an archetype for gas giants across the Universe.

A nine-panel collage showing Hubble images of Jupiter taken under the OPAL (Outer Planet Atmospheres Legacy) program from 2015-2024, with approximately true color. OPAL tracks the Great Red Spot (GRS) and other notable changes in Jupiter’s banded cloud structure of zones and belts over time.Credit: NASA, ESA, A. Simon (GSFC), M. Wong (UC Berkeley), J. DePasquale (STScI)
A nine-panel collage showing Hubble images of Jupiter taken under the OPAL (Outer Planet Atmospheres Legacy) program from 2015-2024, with approximately true color. OPAL tracks the Great Red Spot (GRS) and other notable changes in Jupiter’s banded cloud structure of zones and belts over time.
Credit:
NASA, ESA, A. Simon (GSFC), M. Wong (UC Berkeley), J. DePasquale (STScI)

Saturn

Saturn takes more than 29 years to orbit the Sun, and so OPAL has followed it for approximately one quarter of a Saturnian year (picking up in 2018, after the end of the Cassini mission). Because Saturn is tilted 26.7 degrees, it goes through more profound seasonal changes than Jupiter. Saturnian seasons last approximately seven years. This also means Hubble can view the spectacular ring system from an oblique angle of almost 30 degrees to see the rings tilted edge-on. Edge-on, the rings nearly vanish because they are relatively paper-thin. This will happen again in 2025.

OPAL has followed changes in colors of Saturn’s atmosphere. The varying color was first detected by the Cassini orbiter, but Hubble provides a longer baseline. Hubble revealed slight changes from year-to-year in color, possibly caused by cloud height and winds. The observed changes are subtle because OPAL has covered only a fraction of a Saturnian year. Major changes happen when Saturn progresses into the next season.

Saturn’s mysteriously dark ring spokes, which slice across the ring plane, are transient features that rotate along with the rings. Their ghostly appearance only persists for two or three rotations around Saturn. During active periods, freshly formed spokes continuously add to the pattern. They were first seen in 1981 by Voyager 2. Cassini also saw the spokes during its 13-year-long mission, which ended in 2017. Hubble shows that the frequency of spoke apparitions is seasonally driven, first appearing in OPAL data in 2021. Long-term monitoring shows that both the number and contrast of the spokes vary with Saturn’s seasons.

A six-panel collage titled “Saturn, August 22, 2024, HST WFC3/UVIS.” This “Warhol-esque” array of Saturn images depict real data from multiple filters mapped onto the RGB colors perceptible to the human eye. Each filter combination emphasizes subtle differences in cloud altitude or composition. Infrared spectra from the Cassini mission suggested that Saturn’s aerosol particles may have even more complex chemical diversity than on Jupiter. The OPAL (Outer Planet Atmospheres Legacy) program extends Cassini’s legacy by measuring how the subtle patterns in the clouds vary over time.
n array of Saturn images depict real data from multiple filters mapped onto the RGB colors perceptible to the human eye. Each filter combination emphasizes the subtle differences in cloud altitude or composition. Infrared spectra from the Cassini mission suggested that Saturn’s aerosol particles may have even more complex chemical diversity than on Jupiter.
Credit: NASA, ESA, A. Simon (NASA/GSFC), M. Wong (UC Berkeley), J. DePasquale (STScI)

Uranus

Uranus is tilted on its side so that its spin axis almost lies in the plane of the planet’s orbit. This results in the planet going through radical seasonal changes along its 84-year-long trek around the Sun. The consequence of the planet’s tilt means part of one hemisphere is completely without sunlight, for stretches of time lasting up to 42 years. OPAL has followed the northern pole now tipping toward the Sun.

With OPAL, Hubble first imaged Uranus after the spring equinox, when the Sun was last shining directly over the planet’s equator. Hubble resolved multiple storms with methane ice-crystal clouds appearing at mid-northern latitudes as summer approaches the north pole. Uranus’ north pole now has a thickened photochemical haze with several little storms near the edge of the boundary. Hubble has been tracking the size of the north polar cap and it continues to get brighter year after year. As the northern summer solstice approaches in 2028, the cap may grow brighter still, and will be aimed directly toward Earth, allowing good views of the rings and north pole. The ring system will then appear face-on.

Neptune

When Voyager 2 flew by Neptune 1989, astronomers were mystified by a great dark spot the size of the Atlantic Ocean looming in the atmosphere. Was it long-lived like Jupiter’s Great Red Spot? The question remained unanswered until Hubble was able to show in 1994 that such dark storms were transitory, cropping up and then disappearing over a duration of two to six years each. During the OPAL program, Hubble saw the end of one dark spot and the full life cycle of a second one – both of them migrating toward the equator before dissipating. The OPAL program ensures that astronomers won’t miss another one.

Hubble observations uncovered a link between Neptune’s shifting cloud abundance and the 11-year solar cycle. The connection between Neptune and solar activity is surprising to planetary scientists because Neptune is our solar system’s farthest major planet. It receives sunlight with about 0.1% of the intensity Earth receives. Yet Neptune’s global cloudy weather seems to be influenced by solar activity. Do the planet’s four seasons (each lasting approximately 40 years) also play a role? We may find out, if the OPAL program continues running on Hubble until the year 2179!

A montage of Hubble Space Telescope images of our solar system’s four giant outer planets: Jupiter, Saturn, Uranus, and Neptune, taken under the OPAL (Outer Planet Atmospheres Legacy) program over a duration of 10 years, from 2014 to 2024.
This is a montage of NASA/ESA Hubble Space Telescope views of our solar system’s four giant outer planets: Jupiter, Saturn, Uranus, and Neptune, each shown in enhanced color. The images were taken over nearly 10 years, from 2014 to 2024. This long baseline allows astronomers to track seasonal changes in each planet’s turbulent atmosphere, with the sharpness of the NASA planetary flyby probes of the 1980s. These images were taken under a program called OPAL (Outer Planet Atmospheres Legacy).
From upper-left toward center, the hazy white polar cap on the three teal-colored Uranus images appears more face-on as the planet approaches northern summer.
From center-right to far-center right, three images of the blue planet Neptune show the coming and going of clouds as the Sun’s radiation level changes. Several of Neptune’s mysterious dark spots have come and gone sequentially over OPAL’s decade of observations.
Seven views of yellow-brown Saturn stretch across the center of the mosaic in a triangle—one for each year of OPAL observations—showing the tilt of the angle of the ring plane relative to the view from Earth. Approximately every 15 years the relatively paper-thin rings (about one mile thick) can be seen edge-on. In 2018 they were near their maximum tilt toward Earth. Colorful changes in Saturn’s bands of clouds can be followed as the weather changes.
At bottom center, three images of Jupiter spanning nearly a decade, form a triangle. There are notable changes in Jupiter’s banded cloud structure of zones and belts. OPAL measured shrinking of the legendary Great Red Spot, while its rotation period speeds up.
Credit: NASA, ESA, A. Simon (NASA-GSFC), M. H. Wong (UC Berkeley), J. DePasquale (STScI)

Press release from ESA Hubble.

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Webb finds surprises in Spiderweb protocluster field

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JWST Webb Spiderweb protocluster Hundreds of galaxies appear in this view, which is set against the black background of space. There are many overlapping objects at various distances. They include large, blue foreground stars, some with eight diffraction spikes, and white and pink spiral and elliptical galaxies. Numerous tiny orange dots appear throughout the scene.

Webb finds surprises in Spiderweb protocluster field

Using the NASA/ESA/CSA James Webb Space Telescope, an international team of astronomers have found new galaxies in the Spiderweb protocluster. Their characteristics shed light on the growth of galaxies in these large cosmic cities, with the finding that gravitational interactions in these dense regions are not as important as previously thought.

Hundreds of galaxies appear in this view, which is set against the black background of space. There are many overlapping objects at various distances. They include large, blue foreground stars, some with eight diffraction spikes, and white and pink spiral and elliptical galaxies. Numerous tiny orange dots appear throughout the scene.
Using the NASA/ESA/CSA James Webb Space Telescope, an international team of astronomers have found new galaxies in the Spiderweb protocluster. Their characteristics shed light on the growth of galaxies in these large cosmic cities, with the finding that gravitational interactions in these dense regions are not as important as previously thought.
With the use of Webb’s capabilities, astronomers have now sought to better understand this protocluster and to reveal new galaxies within it. Infrared radiation passes more freely through cosmic dust than visible light, which is scattered by the dust. Because Webb can see infrared light very well, scientists used it to observe regions of the Spiderweb that were previously hidden to us by cosmic dust, and to find out to what degree this dust obscures them.
This image shows the Spiderweb protocluster as seen by Webb’s NIRCam (Near-InfraRed Camera).
Credit: ESA/Webb, NASA & CSA, H. Dannerbauer

Astronomers explore galaxy populations and uncover their physical characteristics across large-scale structures to better understand the build-up of galaxies and how their environments shape their assembly. The Spiderweb protocluster is a well-studied object in the early Universe. Its light has travelled over 10 billion years to reach us, and it shows us a galaxy cluster in formation, composed of more than a hundred known galaxies.

With the use of Webb’s capabilities, astronomers have now sought to better understand this protocluster and to reveal new galaxies inside it. Infrared light passes more freely through cosmic dust than visible light, which is scattered by the dust. Because Webb can see infrared light very well, scientists used it to observe regions of the Spiderweb that were previously hidden to us by cosmic dust, and to find out to what degree this dust obscures them.

“We are observing the build-up of one the largest structures in the Universe, a city of galaxies in construction,” explained Jose M. Pérez-Martínez of the Institute of Astrophysics of the Canary Islands (Instituto de Astrofísica de Canarias) and the University of La Laguna (Universidad de La Laguna in Spain). “We know that most galaxies in local galaxy clusters (the biggest metropolises of the Universe) are old and not very active, whereas in this work we are looking at these objects during their adolescence. As this city in construction grows, their physical properties will also be affected. Now, Webb is giving us new insights into the build-up of such structures for the first time.”

This annotated image shows hundreds of galaxies appearing in this view, which is set against the black background of space. There are many overlapping objects at various distances. Dozens of galaxies are individually identified with white circles, and a large white circle in the centre of the image highlights the collection of gravitationally-bound galaxies in the field. The bottom of the image shows a close-up of seven of these central galaxies. The objects visible in the image include large, blue foreground stars, some with eight diffraction spikes, and white and pink spiral and elliptical galaxies, as well as numerous tiny orange dots that appear throughout the scene.
Using the NASA/ESA/CSA James Webb Space Telescope, an international team of astronomers have found new galaxies in the Spiderweb protocluster. Their characteristics shed light on the growth of galaxies in these large cosmic cities, with the finding that gravitational interactions in these dense regions are not as important as previously thought.
With the use of Webb’s capabilities, astronomers have now sought to better understand this protocluster and to reveal new galaxies within it. Infrared radiation passes more freely through cosmic dust than visible light, which is scattered by the dust. Because Webb can see infrared light very well, scientists used it to observe regions of the Spiderweb that were previously hidden to us by cosmic dust, and to find out to what degree this dust obscures them.
This annotated image shows the galaxy distribution in the Spiderweb protocluster as seen by Webb’s NIRCam (Near-InfraRed Camera). The galaxies are annotated by white circles, and the collection of gravitationally-bound galaxies is identified in the centre of the image. A selection of these galaxies are featured as individual close-ups at the bottom of the image.
Credit: ESA/Webb, NASA & CSA, H. Dannerbauer

Webb enabled the team to study the hydrogen gas using a powerful diagnostic tracer that cannot be studied from ground-based observations. That allowed the team to reveal new, strongly obscured galaxies belonging to the cluster and to study how much they were obscured. This was accomplished using only about 3.5 hours of Webb’s observing time.

“As expected, we found new galaxy cluster members, but we were surprised to find more than expected,” explained Rhythm Shimakawa of Waseda University in Japan. “We found that previously-known galaxy members (similar to the typical star-forming galaxies like our Milky Way galaxy) are not as obscured or dust-filled as previously expected, which also came as a surprise.”

“This can be explained by the fact that the growth of these typical galaxies is not triggered primarily by galaxy interactions or mergers that induce star-formation,” added Helmut Dannerbauer of the Institute of Astrophysics of the Canary Islands (Instituto de Astrofísica de Canarias in Spain). “We now figure this can instead be explained by star formation that is fueled through gas accumulating at different locations all across the object’s large-scale structure.”

This annotated image shows hundreds of galaxies appearing in this view, which is set against the black background of space. There are many overlapping objects at various distances. Dozens of galaxies are individually identified with white circles, and a large white circle in the centre of the image highlights the collection of gravitationally-bound galaxies in the field. The objects visible in the image include large, blue foreground stars, some with eight diffraction spikes, and white and pink spiral and elliptical galaxies, as well as numerous tiny orange dots that appear throughout the scene.
Using the NASA/ESA/CSA James Webb Space Telescope, an international team of astronomers have found new galaxies in the Spiderweb protocluster. Their characteristics shed light on the growth of galaxies in these large cosmic cities, with the finding that gravitational interactions in these dense regions are not as important as previously thought.
With the use of Webb’s capabilities, astronomers have now sought to better understand this protocluster and to reveal new galaxies within it. Infrared radiation passes more freely through cosmic dust than visible light, which is scattered by the dust. Because Webb can see infrared light very well, scientists used it to observe regions of the Spiderweb that were previously hidden to us by cosmic dust, and to find out to what degree this dust obscures them.
This annotated image shows the galaxy distribution in the Spiderweb protocluster as seen by Webb’s NIRCam (Near-InfraRed Camera). The galaxies are annotated by white circles, and the collection of gravitationally-bound galaxies is identified in the centre of the image.
Credit: ESA/Webb, NASA & CSA, H. Dannerbauer

The new results used Webb’s NIRCam observations (Cycle 1 programme #1572, PIs: H. Dannerbauer and Y. Koyama) and are featured in two papers that have been published today in the Astrophysical Journal.  The team is planning to study the (new) galaxy cluster members in more detail and confirm their existence with spectroscopic observations using Webb.

 

Press release from ESA Webb.

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The Sombrero Galaxy, or Messier 104, dazzles in new mid-infrared image from Webb

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Image of a galaxy on the black background of space. The galaxy is a very oblong, blue disk that extends from left to right at an angle (from about 10 o’clock to 5 o’clock). The galaxy has a small bright core at the centre. There is an inner disk that is clearer, with speckles of stars scattered throughout. The outer disk of the galaxy is whiteish-blue, and clumpy, like clouds in the sky. There are different coloured dots, distant galaxies, speckled among the black background of space surrounding the galaxy.

The Sombrero Galaxy, also known as Messier 104 (M104), dazzles in new mid-infrared image from Webb 

A new mid-infrared image from the NASA/ESA/CSA James Webb Space Telescope features the Sombrero galaxy, also known as Messier 104 (M104). The signature, glowing core seen in visible-light images does not shine, and instead a smooth inner disk is revealed. The sharp resolution of Webb’s MIRI (Mid-Infrared Instrument) also brings into focus details of the galaxy’s outer ring, providing insights into how the dust, an essential building block for astronomical objects in the Universe, is distributed. The galaxy’s outer ring shows intricate clumps in the infrared for the first time.

Image of a galaxy on the black background of space. The galaxy is a very oblong, blue disk that extends from left to right at an angle (from about 10 o’clock to 5 o’clock). The galaxy has a small bright core at the centre. There is an inner disk that is clearer, with speckles of stars scattered throughout. The outer disk of the galaxy is whiteish-blue, and clumpy, like clouds in the sky. There are different coloured dots, distant galaxies, speckled among the black background of space surrounding the galaxy.
The NASA/ESA/CSA James Webb Space Telescope recently imaged the Sombrero galaxy with its MIRI (Mid-Infrared Instrument), resolving the clumpy nature of the dust along the galaxy’s outer ring.
The mid-infrared light highlights the gas and dust that are part of star formation taking place among the Sombrero galaxy’s outer disk. The rings of the Sombrero galaxy produce less than one solar mass of stars per year, in comparison to the Milky Way’s roughly two solar masses a year. It’s not a particular hotbed of star formation.
The Sombrero galaxy is around 30 million light-years from Earth in the constellation Virgo.
Credit: NASA, ESA, CSA, STScI

Researchers say the clumpy nature of the dust, where MIRI detects carbon-containing molecules called polycyclic aromatic hydrocarbons, can indicate the presence of young star-forming regions. However, unlike some galaxies studied with Webb, including Messier 82, where 10 times as many stars are born as in the Milky Way galaxy, the Sombrero galaxy is not a particular hotbed of star formation. The rings of the Sombrero galaxy produce less than one solar mass of stars per year, in comparison to the Milky Way’s roughly two solar masses a year.

The supermassive black hole at the centre of the Sombrero galaxy, also known as an active galactic nucleus (AGN), is rather docile, even at a hefty 9-billion-solar masses. It’s classified as a low luminosity AGN, slowly snacking on infalling material from the galaxy, while sending off a bright, relatively small, jet.

Also within the Sombrero galaxy dwell some 2000 globular clusters, a collection of hundreds of thousands of old stars held together by gravity. This type of system serves as a pseudo laboratory for astronomers to study stars – thousands of stars within one system with the same age, but varying masses and other properties is an intriguing opportunity for comparison studies.

In the MIRI image, galaxies of varying shapes and colours litter the background of space. The different colours of these background galaxies can tell astronomers about their properties, including how far away they are.

The Sombrero galaxy is around 30 million light-years from Earth in the constellation Virgo.

Stunning images like this, and an array of discoveries in the study of exoplanets, galaxies through time, star formation, and our own Solar System, are still just the beginning. Recently, scientists from all over the world converged—virtually—to apply for observation time with Webb during its fourth year of science operations, which begins in July 2025.

A two panel image. The top image is Webb’s view of the Sombrero galaxy, the bottom image is Hubble’s view. In the Webb view, the galaxy is a very oblong, blue disk that extends from left to right at an angle (from about 10 o’clock to 5 o’clock). The galaxy has a small bright core at the centre. There is a clear inner disk that has speckles of stars scattered throughout. The outer disk of the galaxy is whiteish-blue, and clumpy, like clouds in the sky. In the Hubble view, the galaxy is an oblong, pale white disk with a glowing core over the inner disk. The outer disk is darker and clumpy.
This image compares the view of the famous Sombrero Galaxy in mid-infrared light (top) and visible light (bottom). The James Webb Space Telescope’s MIRI (Mid-Infrared Instrument) reveals the smooth inner disk of the galaxy, while the Hubble Space Telescope’s visible light image shows the large and extended glow of the central bulge of stars.
Both the Webb and Hubble images resolve the clumpy nature of the dust that makes up the Sombrero galaxy’s outer ring.
Credit: NASA, ESA, CSA, STScI, Hubble Heritage Team (STScI/AURA)

General Observer time with Webb is more competitive than ever. A record-breaking 2377 proposals were submitted by the 15 October 2024 deadline, requesting about 78,000 hours of observation time. This is an oversubscription rate, the ratio defining the observation hours requested versus the actual time available in one year of Webb’s operations, of around 9 to 1.

The proposals cover a wide array of science topics, with distant galaxies being among the most requested observation time, followed by exoplanet atmospheres, stars and stellar population, then exoplanet systems.

Press release from ESA Webb

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Hubble sees aftermath of galaxy’s scrape with Milky Way, at the Large Magellanic Cloud (LMC)

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A whitish, whirlpool-like galaxy at middle of top edge, and a tadpole-shaped structure sweeps from left to right across lower half. A label pointing to outer, left of galaxy reads “Earth.” Faint, purple haze labelled “Milky Way Halo” surrounds galaxy and stretches to graphic’s edges. The tadpole-shaped object is the Large Magellanic Cloud, or LMC, with its own halo and streaming tail. Semi-circular, progressively darker layers of purple labelled “LMC Halo” surround the LMC, which appears roughly circular, with a central, light yellow bar. Cloud-like features sprinkled with white specks surround this bar. Trailing the LMC is a large, tail-like feature labelled “Stream.” Three light blue lines point from the label “Earth” through the LMC’s halo, and to three corresponding quasars, which are off screen.

Hubble sees aftermath of galaxy’s scrape with Milky Way, at the Large Magellanic Cloud (LMC)

Encounter blew away most of smaller galaxy’s gaseous halo

Labelled “artist’s concept” at bottom right, the graphic shows a closeup of a dwarf galaxy, which appears roughly circular with a light yellow bar in the centre. Faint, blue, wispy, cloud-like features surround this yellow bar, and they are sprinkled with tiny white specks. A wide, wispy, purple arc appears to the left of the galaxy. Trailing the galaxy is a large, faint, wide, tail-like feature.
This artist’s concept shows a closeup of the Large Magellanic Cloud (LMC), a dwarf galaxy that is one of the Milky Way galaxy’s nearest neighbours. Scientists think that the LMC has just completed its closest approach to the much more massive Milky Way. This encounter has blown away most of the spherical halo of gas that surrounds the LMC. The bright purple bow shocks represent the leading edge of the LMC’s halo, which is being compressed as the Milky Way’s halo pushes back against the incoming LMC. The pressure is stripping much of the LMC’s halo and blowing it backward into a streaming tail of gas. The dwarf galaxy is cocooned within its remaining halo. An actual science image of the LMC is combined with an artist’s rendering of the galaxy’s halo.
Credit: NASA, ESA, R. Crawford (STScI)

In an epic story of survival witnessed by the NASA/ESA Hubble Space Telescope, one of our nearest galactic neighbours has crashed through the Milky Way galaxy’s gaseous halo and lived to tell the tale. But in the process, this dwarf galaxy, called the Large Magellanic Cloud (LMC), has been stripped of most of its own surrounding halo of gas. Researchers were surprised to find such an extremely small gaseous halo remaining — one around 10 times smaller than halos of other galaxies of similar mass. Still, the LMC has held onto enough of its gas to keep forming new stars. A smaller galaxy wouldn’t have survived such an encounter. This is the first time astronomers have been able to measure the size of the LMC’s halo — something they could do only with Hubble.

The Large Magellanic Cloud, also called the LMC, is one of the Milky Way galaxy’s nearest neighbours. This dwarf galaxy looms large in the southern nighttime sky at 20 times the apparent diameter of the full Moon.

Many researchers theorise that the LMC is not in orbit around our galaxy, but is just passing by. Those scientists think that the LMC has just completed its closest approach to the much more massive Milky Way. This passage has blown away most of the spherical halo of gas that surrounds the LMC.

Now, for the first time, astronomers have been able to measure the size of the LMC’s halo — something they could do only with Hubble. In a new study published in the Astrophysical Journal Letters, researchers were surprised to find that it is so extremely small — about 50 000 light-years across. That’s around 10 times smaller than the halos of other galaxies that are the same mass as the LMC. Its compactness tells the story of its encounter with the Milky Way.

“The LMC is a survivor,” said Andrew Fox of AURA/STScI for the European Space Agency in Baltimore, who was principal investigator on the observations. “Even though it’s lost a lot of its gas, it’s got enough left to keep forming new stars. So new star-forming regions can still be created. A smaller galaxy wouldn’t have lasted — there would be no gas left, just a collection of aging red stars.”

Though quite a bit the worse for wear, the LMC still retains a compact, stubby halo of gas — something that it wouldn’t have been able to hold onto gravitationally had it been less massive. The LMC is 10 percent the mass of the Milky Way.

“Because of the Milky Way’s own giant halo, the LMC’s gas is getting truncated, or quenched,” explained STScI’s Sapna Mishra, the lead author of the paper chronicling this discovery. “But even with this catastrophic interaction with the Milky Way, the LMC is able to retain 10 percent of its halo because of its high mass.”

A whitish, whirlpool-like galaxy at middle of top edge, and a tadpole-shaped structure sweeps from left to right across lower half. A label pointing to outer, left of galaxy reads “Earth.” Faint, purple haze labelled “Milky Way Halo” surrounds galaxy and stretches to graphic’s edges. The tadpole-shaped object is the Large Magellanic Cloud, or LMC, with its own halo and streaming tail. Semi-circular, progressively darker layers of purple labelled “LMC Halo” surround the LMC, which appears roughly circular, with a central, light yellow bar. Cloud-like features sprinkled with white specks surround this bar. Trailing the LMC is a large, tail-like feature labelled “Stream.” Three light blue lines point from the label “Earth” through the LMC’s halo, and to three corresponding quasars, which are off screen.
This artist’s concept shows the Large Magellanic Cloud, or LMC, in the foreground as it passes through the gaseous halo of the much more massive Milky Way galaxy. The encounter has blown away most of the spherical halo of gas that surrounds the LMC, as illustrated by the trailing gas stream reminiscent of a comet’s tail. Still, a compact halo remains, and scientists do not expect this residual halo to be lost. The team surveyed the halo by using the background light of 28 quasars, an exceptionally bright type of active galactic nucleus that shines across the Universe like a lighthouse beacon. Their light allows scientists to ‘see’ the intervening halo gas indirectly through the absorption of the background light. The lines represent the Hubble Space Telescope’s view from its orbit around Earth to the distant quasars through the LMC’s gas.
Credit: NASA, ESA, R. Crawford (STScI)

A gigantic hair dryer

Most of the LMC’s halo was blown away by a phenomenon called ram-pressure stripping. The dense environment of the Milky Way pushes back against the incoming LMC and creates a wake of gas trailing the dwarf galaxy — like the tail of a comet.

“I like to think of the Milky Way as this giant hairdryer, and it’s blowing gas off the LMC as it comes into us,” said Fox. “The Milky Way is pushing back so forcefully that the ram pressure has stripped off most of the original mass of the LMC’s halo. There’s only a little bit left, and it’s this small, compact leftover that we’re seeing now.”

As the ram pressure pushes away much of the LMC’s halo, the gas slows down and eventually will rain into the Milky Way. But because the LMC has just passed its closest approach to the Milky Way and is moving outward into deep space again, scientists do not expect the whole halo will be lost.

Only with Hubble

To conduct this study, the research team analysed ultraviolet observations from the Mikulski Archive for Space Telescopes at STScI. Most ultraviolet light is blocked by Earth’s atmosphere, so it cannot be observed with ground-based telescopes. Hubble is currently the only space telescope that is tuned to detect these wavelengths of light, so this study was only possible with Hubble.

The team surveyed the halo by using the background light of 28 bright quasars. The brightest type of active galactic nucleus, quasars are believed to be powered by supermassive black holes. Shining like lighthouse beacons, they allow scientists to ‘see’ the intervening halo gas indirectly through the absorption of the background light. Quasars reside throughout the Universe at extreme distances from our galaxy.

The scientists used data from Hubble’s Cosmic Origins Spectrograph (COS) to detect the presence of the halo gas by the way it absorbs certain colours of light from background quasars. A spectrograph breaks light into its component wavelengths to reveal clues to the object’s state, temperature, speed, quantity, distance, and composition. With COS, they measured the velocity of the gas around the LMC, which allowed them to determine the size of the halo.

Because of its mass and proximity to the Milky Way, the LMC is a unique astrophysics laboratory. Seeing the LMC’s interplay with our galaxy helps scientists understand what happened in the early Universe, when galaxies were closer together. It also shows just how messy and complicated the process of galaxy interaction is.

“This is a fantastic example of the cutting-edge science still being enabled by Hubble’s unique capabilities,” said Professor Carole Mundell, Director of Science at the European Space Agency. “This result gives us precious new insights into the complex history of the Milky Way and its nearby satellite galaxies.”

Looking to the future

The team will next study the front side of the LMC’s halo, an area that has not yet been explored.

“In this new programme, we are going to probe five sightlines in the region where the LMC’s halo and the Milky Way’s halo are colliding,” said co-author Scott Lucchini of the Center for Astrophysics | Harvard & Smithsonian. “This is the location where the halos are compressed, like two balloons pushing against each other.”

A 3-panel graphic labelled “artist’s concept” at bottom, right corner. Each of the three panels shows the same whitish, whirlpool-like spiral galaxy at middle of top edge. A faint, purple haze surrounds galaxy and stretches to panel’s edges. At the middle of the right side of the first panel, a white dot surrounded by fuzzy, lighter purple halo approaches. In middle panel, a pronounced, light purple bow shock develops to left part of the halo. The right part of halo is being stripped and blown back into a streaming tail of gas. The bottom panel shows the tail becoming longer and more defined as the now tadpole-like object curves below the spiral galaxy and sweeps toward the upper left.
This artist’s concept illustrates the Large Magellanic Cloud’s (LMC’s) encounter with the Milky Way galaxy’s gaseous halo. In the top panel, at the middle of the right side, the LMC begins crashing through our galaxy’s much more massive halo. The bright purple bow shock represents the leading edge of the LMC’s halo, which is being compressed as the Milky Way’s halo pushes back against the incoming LMC. In the middle panel, part of the halo is being stripped and blown back into a streaming tail of gas that eventually will rain into the Milky Way. The bottom panel shows the progression of this interaction, as the LMC’s comet-like tail becomes more defined. A compact LMC halo remains. Because the LMC is just past its closest approach to the Milky Way and is moving outward into deep space again, scientists do not expect the residual halo will be lost.
Credit: NASA, ESA, R. Crawford (STScI)

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The Hubble Space Telescope is a project of international cooperation between ESA and NASA.
Image credit: NASA, ESA, R. Crawford (STScI)

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Press release from ESA Hubble

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Webb and Hubble examine spooky spiral galaxies: IC 2163 and NGC 2207

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Webb and Hubble examine spooky spiral galaxies: IC 2163 and NGC 2207

Stare deeply at these galaxies. They appear as if blood is pumping through the top of a flesh-free face. The long, ghastly ‘stare’ of their searing eye-like cores shines out into the supreme cosmic darkness.

Two spiral galaxies take up almost the entire view and appear to be overlapping. The galaxy at left, IC 2163, is smaller and more compact than the galaxy at right, NGC 2207. The black background of space is dotted with foreground stars and extremely distant galaxies.
The gruesome palette of these galaxies is owed to a mix of mid-infrared light from the NASA/ESA/CSA James Webb Space Telescope, and visible and ultraviolet light from the NASA/ESA Hubble Space Telescope. The pair grazed one another millions of years ago. The smaller spiral on the left, catalogued as IC 2163, passed behind NGC 2207, the larger spiral galaxy at right.
Both have increased star formation rates. Combined, they are estimated to form the equivalent of two dozen new stars that are the size of the Sun annually. Our Milky Way galaxy forms the equivalent of two or three new Sun-like stars per year.
Both galaxies have hosted seven known supernovae, each of which may have cleared space in their arms, rearranging gas and dust that later cooled, and allowed many new stars to form. (Find these areas by looking for the bluest regions).
Credit: NASA, ESA, CSA, STScI

These galaxies have only grazed one another so far, with the smaller spiral on the left, catalogued as IC 2163, ever so slowly ‘creeping’ behind NGC 2207, the spiral galaxy on the right, millions of years ago.

The pair’s macabre colours represent a combination of mid-infrared light from the NASA/ESA/CSA James Webb Space Telescope and visible and ultraviolet light from the NASA/ESA Hubble Space Telescope.

Look for potential evidence of their ‘light scrape’ in the shock fronts, where material from the galaxies may have slammed together. These lines represented in brighter red, including the ‘eyelids’, may cause the appearance of the galaxies’ bulging, vein-like arms.

The galaxies’ first pass may have also distorted their delicately curved arms, pulling out tidal extensions in several places. The diffuse, tiny spiral arms between IC 2163’s core and its far left arm may be an example of this activity. Even more tendrils look like they’re hanging between the galaxies’ cores. Another extension ‘drifts’ off the top of the larger galaxy, forming a thin, semi-transparent arm that practically runs off screen.

Both galaxies have high star formation rates, like innumerable individual hearts fluttering all across their arms. Each year, the galaxies produce the equivalent of two dozen new stars that are the size of the Sun. Our Milky Way galaxy only forms the equivalent of two or three new Sun-like stars per year. Both galaxies have also hosted seven known supernovae in recent decades, a high number compared to an average of one every 50 years in the Milky Way. Each supernova may have cleared space in the galaxies’ arms, rearranging gas and dust that later cooled, and allowed many new stars to form.

To spot the star-forming ‘action sequences,’ look for the bright blue areas captured by Hubble in ultraviolet light, and the pink and white regions detailed mainly by Webb’s mid-infrared data. Larger areas of stars are known as super star clusters. Look for examples of these in the top-most spiral arm that wraps above the larger galaxy and points left. Other bright regions in the galaxies are mini starbursts — locations where many stars form in quick succession. Additionally, the top and bottom ‘eyelid’ of IC 2163, the smaller galaxy on the left, is filled with newer star formation and burns brightly.

A graphic labelled “Hubble and Webb Space Telescopes; Spiral Galaxies IC 2163 and NGC 2207.” At the centre are two overlapping spiral galaxies set against the black background of space.
This image of galaxies IC 2163 and NGC 2207, captured by the Hubble and James Webb space telescopes. Hubble’s data are from its Wide Field Planetary Camera 2 (WFPC2). Webb’s data are from its Mid-InfraRed Instrument (MIRI).
The image shows a scale bar, compass arrows, and colour key for reference.
The scale bar is labelled in light-years along the top, which is the distance that light travels in one Earth-year. (It takes three years for light to travel a distance equal to the length of the scale bar.) One light-year is equal to about 9.46 trillion kilometres.
The scale bar is also labelled in arcminutes, which is a measure of angular distance on the sky. One arcsecond is equal to an angular measurement of 1/3600 of one degree. There are 60 arcminutes in a degree and 60 arcseconds in an arcminute. (The full Moon has an angular diameter of about 30 arcminutes.) The actual size of an object that covers one arcsecond on the sky depends on its distance from the telescope.
The north and east compass arrows show the orientation of the image on the sky. Note that the relationship 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 invisible ultraviolet, visible, and mid-infrared wavelengths of light that have been translated into visible-light colours. The colour key shows which WFPC2 and MIRI filters were used when collecting the light. The colour of each filter name is the visible-light colour used to represent the infrared light that passes through that filter.
Credit: NASA, ESA, CSA, STScI

What’s next for these spirals? Over many millions of years, the galaxies may swing by one another repeatedly. It’s possible that their cores and arms will meld, leaving behind completely reshaped arms, and an even brighter, cyclops-like ‘eye’ at the core. Star formation will also slow down once their stores of gas and dust deplete, and the scene will calm.

Two spiral galaxies take up almost the entire view and appear to be overlapping. They are angled from top left to bottom right. The galaxy at left, IC 2163, is smaller and more compact than the galaxy at right, NGC 2207. The background of space is black, dotted with tiny foreground stars and extremely distant galaxies.
The James Webb Space Telescope’s mid-infrared image of galaxies IC 2163 and NGC 2207 recalls the iciness of long-dead bones mixed with eerie vapours. Two large luminous ‘eyes’ lie at the galaxies’ cores, and gauzy spiral arms reach out into the vast distances of space.
Webb’s mid-infrared image excels at showing where the cold dust glows throughout these galaxies — and helps pinpoint where stars and star clusters are buried within the dust. Find these regions by looking for the pink dots along the spiral arms. Many of these areas are home to actively forming stars that are still encased in the gas and dust that feeds their growth. Other pink dots may be objects that lie well behind these galaxies, including extremely distant active supermassive black holes known as quasars.
The largest, brightest pink region that glimmers with eight prominent diffraction spikes at the bottom right is a mini starburst — a location where many stars are forming in quick succession. Find the lace-like holes in the spiral arms. These areas are brimming with star formation.
Finally, scan the black background of space, where objects shine brightly in a rainbow of colours. Blue circles with tiny diffraction spikes are foreground stars. Objects without spikes are very distant galaxies.
Credit: NASA, ESA, CSA, STScI

Want to ‘pull apart’ these images? Examine the galaxies’ skeleton-like appearance in Webb’s mid-infrared image, and compare the Hubble and Webb images side by side.

Two views of the same object are shown side by side, split evenly. The Hubble observation is at left, and the Webb observation is at right. Both show an angled pair of spiral galaxies, IC 2163 at top left, and NGC 2207, at bottom right.
These are two views of the same scene, each showing two overlapping spiral galaxies, IC 2163 at left and NGC 2207 at right. The NASA/ESA Hubble Space Telescope’s ultraviolet- and visible-light observation is at left, and the NASA/ESA/CSA James Webb Space Telescope’s mid-infrared light observation is at right.
In Hubble’s image, the star-filled spiral arms glow brightly in blue, and the galaxies’ cores in orange. Both galaxies are covered in dark brown dust lanes, which obscure the view of IC 2163’s core at left.
In Webb’s image, cold dust takes centre stage, casting the galaxies’ arms in white. Areas where stars are still deeply embedded in the dust appear pink. Other pink dots may be objects that lie well behind these galaxies, including active supermassive black holes known as quasars.
Turn your eye toward the bottom right of the Webb image. The largest, brightest pink region that glimmers with eight prominent diffraction spikes is a mini starburst — a location where many stars are forming in quick succession. The same region in the Hubble image appears as a bright blue cluster of stars.
The lace-like holes in the white spiral arms of Webb’s images are often where supernovae exploded long ago. In the same regions, Hubble shows these areas are now populated with newer stars.
The black areas to the upper right and lower left of the Hubble image do not contain any data.
Credit: NASA, ESA, CSA, STScI

 

Press release from ESA Webb.

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Webb finds candidates for first young brown dwarfs outside the Milky Way, in the star cluster NGC 602

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young brown dwarfs outside the Milky Way NGC 602 A star cluster is shown inside a large nebula of many-coloured gas and dust. The material forms dark ridges and peaks of gas and dust surrounding the cluster, lit on the inner side, while layers of diffuse, translucent clouds blanket over them. Around and within the gas, a huge number of distant galaxies can be seen, some quite large, as well as a few stars nearer to us which are very large and bright.

Webb finds candidates for first young brown dwarfs outside the Milky Way, in the star cluster NGC 602

An international team of astronomers has used the NASA/ESA/CSA James Webb Space Telescope to detect the first rich population of brown dwarf candidates outside the Milky Way in the star cluster NGC 602.

Near the outskirts of the Small Magellanic Cloud, a satellite galaxy roughly 200 000 light-years from Earth, lies the young star cluster NGC 602. The local environment of this cluster is a close analogue of what existed in the early Universe, with very low abundances of elements heavier than hydrogen and helium. The existence of dark clouds of dense dust and the fact that the cluster is rich in ionised gas also suggest the presence of ongoing star formation processes. Together with its associated HII [1] region N90, which contains clouds of ionised atomic hydrogen, this cluster provides a valuable opportunity to examine star formation scenarios under dramatically different conditions from those in the solar neighbourhood.

An international team of astronomers, including Peter Zeidler, Elena Sabbi, Elena Manjavacas and Antonella Nota, used Webb to observe NGC 602 and they detected candidates for the first young brown dwarfs outside our Milky Way.

“Only with the incredible sensitivity and spatial resolution in the correct wavelength regime is it possible to detect these objects at such great distances,” shared lead author Peter Zeidler of AURA/STScI for the European Space Agency. “This has never been possible before and also will remain impossible from the ground for the foreseeable future.”

Brown dwarfs are the more massive cousins of giant gas planets (typically ranging from roughly 13 to 75 Jupiter masses, and sometimes lower). They are free-floating, meaning that they are not gravitationally bound to a star as exoplanets are. However, some of them share characteristics with exoplanets, like their atmospheric composition and storm patterns.

“Until now, we’ve known of about 3000 brown dwarfs, but they all live inside our own galaxy,” added team member Elena Manjavacas of AURA/STScI for the European Space Agency.

“This discovery highlights the power of using both Hubble and Webb to study young stellar clusters,” explained team member Antonella Nota, executive director of the International Space Science Institute in Switzerland and the previous Webb Project Scientist for ESA. “Hubble showed that NGC602 harbors very young low mass stars, but only with Webb we can finally see the extent and the significance of the substellar mass formation in this cluster. Hubble and Webb are an amazingly powerful telescope duo!”

“Our results fit very well with the theory that the mass distribution of bodies below the hydrogen burning limit is simply a continuation of the stellar distribution,” shared Zeidler. “It seems they form in the same way, they just don’t accrete enough mass to become a fully fledged star.”

The team’s data include a new image from Webb’s Near-InfraRed Camera (NIRCam) of NGC 602, which highlights the cluster stars, the young stellar objects, and the surrounding gas and dust ridges, as well as the gas and dust itself, while also showing the significant contamination by background galaxies and other stars in the Small Magellanic Cloud. These observations were made in April 2023.

“By studying the young metal-poor brown dwarfs newly discovered in NGC602, we are getting closer to unlocking the secrets of how stars and planets formed in the harsh conditions of the early Universe,“ added team member Elena Sabbi of NSF’s NOIRLab, the University of Arizona, and the Space Telescope Science Institute.

“These are the first substellar objects outside the Milky Way” added Manjavacas. “We need to be ready for new ground-breaking discoveries in these new objects!”

These observations were made as part of the JWST GO programme #2662 (PI: P. Zeidler). The results have been published in The Astrophysical Journal.

A star cluster is shown inside a large nebula of many-coloured gas and dust. The material forms dark ridges and peaks of gas and dust surrounding the cluster, lit on the inner side, while layers of diffuse, translucent clouds blanket over them. Around and within the gas, a huge number of distant galaxies can be seen, some quite large, as well as a few stars nearer to us which are very large and bright.
Near the outskirts of the Small Magellanic Cloud, a satellite galaxy roughly 200 000 light-years from Earth, lies the young star cluster NGC 602, which is featured in this new image from the NASA/ESA/CSA James Webb Space Telescope. This image includes data from Webb’s NIRCam (Near-InfraRed Camera) and MIRI (Mid-InfraRed Instrument).
The local environment of this cluster is a close analogue of what existed in the early Universe, with very low abundances of elements heavier than hydrogen and helium. The existence of dark clouds of dense dust and the fact that the cluster is rich in ionised gas also suggest the presence of ongoing star formation processes. This cluster provides a valuable opportunity to examine star formation scenarios under dramatically different conditions from those in the solar neighbourhood.
An international team of astronomers, including Peter Zeidler, Elena Sabbi, and Antonella Nota, used Webb to observe NGC 602 and detected candidates for the first young brown dwarfs outside our Milky Way.
Credit: ESA/Webb, NASA & CSA, P. Zeidler, E. Sabbi, A. Nota, M. Zamani (ESA/Webb)

Notes

[1] Some of the most beautiful extended objects that we can see are known as HII regions, also called diffuse or emission nebulae. They contain mostly ionised hydrogen and are found throughout the interstellar medium in the Milky Way and in other galaxies.

Press release from ESA Webb.

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