You can’t judge a star by its protoplanetary disc

Credit: ALMA(ESO/NAOJ/NRAO)/A. Ribas et al.

 

This image tells a story of redemption for a lonely star. The young star MP Mus (PDS 66) was once thought to be all alone in the universe, surrounded by nothing but a featureless band of gas and dust known as a protoplanetary disc. In most cases, the material inside a protoplanetary disc condenses to form new planets around the star, leaving large gaps where the gas and dust used to be. These features are seen in almost every disc — but not in MP Mus’.

When astronomers first observed it with the Atacama Large Millimeter/submillimeter Array (ALMA), they saw a smooth, planet-free disc, shown here in the right image. The team, led by Álvaro Ribas, an astronomer at the University of Cambridge, UK, gave this star another chance and re-observed it with ALMA at longer wavelengths that probe even deeper into the protoplanetary disc than before. These new observations, shown in the left image, revealed a gap and a ring that had been obscured in previous observations, suggesting that MP Mus might have company after all.

Meanwhile, another piece of the puzzle was being revealed in Germany as Miguel Vioque, an astronomer at ESO, studied this same star with the European Space Agency’s (ESA’s) Gaia mission. Vioque noticed something suspicious — the star was wobbling. A bit of gravitational detective work, together with insights from the new disc structures revealed by ALMA, showed that this motion could be explained by the presence of a gas giant exoplanet.

Both teams presented their joint results in a new paper published in Nature Astronomy. In what they describe as “a beautiful merging of two groups approaching the same object from different angles”, they show that MP Mus isn’t so boring after all.

Scientific Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Science Blog

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Additional information

This text was adapted from a Picture of the Week published by the European Southern Observatory (ESO), an ALMA partner on behalf of Europe.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Contacts:

Nicolás Lira
Education and Public Outreach Officer
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

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Comet’s Water Mirrors Earth’s Oceans, Strengthening Life-Origin Theory

Origins of Earth’s Water. Terrestrial H2O is thought to have been delivered several billion years ago, by a combination of cometary, asteroidal, and meteoritic impacts. In contrast to previous findings, new work using the ALMA telescope shows that the isotopic (D/H) ratio in Earth’s water is consistent with delivery by Halley-type comets. Credit: NASA / Theophilus Britt Griswold

ALMA maps showing the distribution of ordinary water (H₂O) and heavy water (HDO) in comet 12P/Pons-Brooks. The contours indicate how strong the signals are, with higher contours showing stronger detections. The small panels in the upper right display the strength of the water signals at the comet’s center. The lower left shows ALMA’s resolution for these observations, while the lower right indicates the direction toward the Sun and the comet’s path through space. Credit: M. Coordiner et al. - ALMA (ESO/NAOJ/NRAO)

A. I. generated illustration showing a comet approaching Earth.
Credit: N. Lira - ALMA (ESO/NAOJ/NRAO)

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ALMA observations of Halley-type comet 12P/Pons-Brooks reveal water with the same isotopic signature as Earth’s oceans

New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed that water in the Halley-type comet 12P/Pons-Brooks has an isotopic composition virtually identical to that of Earth’s oceans. This finding strengthens the theory that comets may have played a crucial role in delivering water, and possibly some of the molecular ingredients for life, to our young planet.

Earth’s water is thought to have arrived billions of years ago through impacts by comets, asteroids, and meteorites. While previous measurements in many comets showed significant differences from Earth’s water, the new results provide the strongest evidence yet that at least some Halley-type comets carried water with the same chemical “fingerprint” as that found on our planet.

Using ALMA’s exceptional sensitivity and imaging capabilities, an international team led by Martin Cordiner (NASA’s Goddard Space Flight Center) mapped, for the first time, the spatial distribution of both ordinary water (H₂O) and heavy water (HDO, containing deuterium) in a comet’s coma—the cloud of gas surrounding its nucleus. These observations, made as 12P/Pons-Brooks approached the Sun, were combined with infrared measurements from NASA’s Infrared Telescope Facility (IRTF) to determine the ratio of deuterium to hydrogen (D/H) with unprecedented precision for a comet of this class.

Remarkably, the D/H ratio—(1.71 ± 0.44) × 10⁻⁴—is the lowest ever measured in a Halley-type comet and falls at the lower end of all cometary values, matching Earth’s oceans. “Comets like this are frozen relics left over from the birth of our Solar System 4.5 billion years ago,” said Cordiner. “Since Earth is believed to have formed from materials lacking water, comet impacts have long been suggested as a source of Earth’s water. Our new results provide the strongest evidence yet that at least some Halley-type comets carried water with the same isotopic signature as that found on Earth, supporting the idea that comets could have helped make our planet habitable.”

“By mapping both H2O and HDO in the comet’s coma, we can tell if these gases are coming from the frozen ices within the solid body of the nucleus, rather than forming from chemistry or other processes in the gas coma,” said NASA’s Stefanie Milam, co-author of the study.

The detection of faint heavy water signals so close to the nucleus—never before mapped in a comet—was only possible thanks to ALMA’s unmatched imaging power.

Scientific Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Releases

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Additional Information

The research paper appeared in Nature Astronomy as "A D/H ratio consistent with Earth’s water in Halley-type comet 12P from ALMA HDO mapping" by M. Coordiner et al.

This text is based on the original press release by the National Radio Astronomy Observatory (NRAO), an ALMA partner on behalf of North America.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Contacts:

Nicolás Lira
Education and Public Outreach Officer
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236
Email: jmalusky@nrao.edu

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

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A unique supergiant star Science Blog A unique supergiant star

A unique supergiant star
Credit: ALMA(ESO/NAOJ/NRAO)/M. Siebert et al.

What you see in this photo is a red supergiant star expelling a cloud of gas and dust as it nears the end of its life. These nebulae are common around supergiant stars; however, this particular cloud presents an unexpected and considerable mystery for astronomers.

This is the largest cloud of ejected material to have been found around a supergiant star, at an enormous 1.4 light years across. Astronomers studied this star, Stephenson 2 DFK 52, with the Atacama Large Millimeter/submillimeter Array (ALMA) while studying other supergiants in its vicinity. DFK 52 is rather similar to Betelgeuse, another famous red supergiant, so they were expecting to see a similar cloud around it. However, if DFK 52 was as close to us as Betelgeuse is, the cocoon around it would be as wide in the sky as a third of a full Moon.

These new ALMA observations allow astronomers to measure the amount of material surrounding the star and its velocity. The parts that are moving towards us are highlighted in blue, and the sections that are moving away are highlighted in red. The data show that about 4,000 years ago, the star went through an episode of extreme mass shedding, and then slowed down to its current rate, more similar to that of Betelgeuse. DFK 52 is estimated to be 10-15 times more massive than the Sun, and by now it has already lost 5-10% of its mass.

It’s still a mystery as to how the star managed to expel so much material in such a short timeframe. Could it be an odd interaction with a companion star? Why is the shape of the cloud so unusually complex? Are there more supergiants like this out there? Deciphering why DFK 52 has already shed so much material will help astronomers understand how it will meet its end: a supernova explosion sometime in the next million years.

Science Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Science Blog

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Additional Information

The research paper is accepted for publication in Astronomy & Astrophysics as "Stephenson 2 DFK 52: Discovery of an exotic red supergiant in the massive stellar cluster RSGC2" by Siebert et al.

This article is based on a picture of the week issued by the European Southern Observatory (ESO), an ALMA partner on behalf of Europe.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Contact:

Nicolás Lira
Education and Public Outreach Officer
oint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

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Discovery of Protoplanetary Disk Caught in Explosion Driven by Stellar Jet

The left image shows 12CO (carbon monoxide) emission lines of WSB 52 at various wavelengths. The dashed line represents the expanding bubble model, and the red dot indicates the location of WSB 52. Panel 0 shows the zoomed-in continuum image of the protoplanetary disk. Panels 7 and 8 show the strong influence of a foreground molecular cloud. The right image is a cross-sectional diagram of the newly found phenomenon, showing the heights of the expansion bubbles that correspond to the number of each 12CO emission line image on the left. Credit: ALMA (ESO/NAOJ/NRAO), M. Aizawa et al.

Masataka Aizawa (Ibaraki University), who led this research, said, “We came upon this phenomenon by chance while reanalyzing ALMA archival data. In science fiction, there are scenes where a beam is fired at something to destroy it, causing an explosion with debris flying back at the shooter. Similar things occur in real astronomical phenomena, but with greater intensity. Through this discovery, I once again realized that nature is far more complex than humans think. In future research, I hope to explore further the effects of the explosions on the formation of stars and planetary systems.”

A Short animation conceptually showing the chain of events found through this research: A jet emitted by a baby star collides with a cloud of cold molecular gas, setting off the explosive expansion of a bubble.  The shock front created by the expanding bubble collides with the star’s disk and distorts it. Credit: ALMA (ESO/NAOJ/NRAO), M. Aizawa et al.

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Using ALMA archival data, Masataka Aizawa of Ibaraki University and his team discovered an evenly expanding bubble structure engulfing and distorting the protoplanetary disk around the young star WSB 52. Astronomers think that the bubble structure formed several hundred years ago by a stellar jet in the vicinity of the star, as its center aligns with the axis of the disk. This finding suggests that the disk, which serves as a seedbed for planets, is exposed to a harsher environment than previously thought.

Stars are formed through the aggregation of gas in molecular clouds driven by gravity. As gas falls toward the star, it retains its angular momentum, creating a rotating disk known as a protoplanetary disk. The gas and dust in this rotating disk coagulate, eventually forming planets. According to this theory, not all of the gas that falls into the star is absorbed for star formation; instead, much of it is ejected as jets or outflows before returning to the surrounding star-forming environment.

By reanalyzing ALMA archival data of the young star WSB 52, which had previously been identified as having a protoplanetary disk, the research team unexpectedly discovered an explosively expanding bubble structure near the disk. Co-author Ryuta Orihara (the University of Tokyo, formerly a doctoral student at Ibaraki University) said, “ALMA’s high spectroscopic capabilities have unveiled the cross-section of an expanding bubble structure, as if it was examined with a CT scan.”

Further detailed analysis revealed a shock front created by the expanding bubble near the star, with the disk being distorted by the collision, and a fragment of gas in the disk being blown away. Similar expanding bubble structures have been detected around other young stars through visible and near-infrared observations; however, none of them have indicated signs of collision between the bubble and the disk as observed this time. This phenomenon was also unpredicted by the theories.

In addition, the research team found that the bubble’s center is aligned with the disk’s rotation axis through the analysis of the spatial relationship between the disk and the bubble. Based on this configuration, as well as the shape and energy of the bubble, the team concluded that a high-speed jet, emitted from WSB 52 hundreds of years ago, collided with cold material, causing the gas to compress. Then the increased pressure from the compression caused the gas to explode, which resulted in the formation of the expanding bubble. The team also discovered that the explosion may have occurred closer to the central star since the bubble’s center exhibits motion away from the star. This suggests that the impact of the bubble collision immediately after its formation could have been far more intense than observed, indicating that the disk we see today is the result of having undergone such an impact.

Previously, stellar jets were thought to serve primarily as indirect suppliers of matter and energy for the surrounding environment. However, this research proved that star jets have a direct impact on the protoplanetary disk via the formation of bubble structures. Co-author Munetake Momose (Ibaraki University, with a cross-appointment at NAOJ from July 2025) said, “Stellar jets are a universal phenomenon observed in young stars, but this research has revealed a previously unknown role that they play.” If explosive bubble expansion like this one occurs universally around young stars, it may have had a significant impact on the formation of various planetary systems, including our Solar System. A future in-depth study is expected to investigate the frequency of these explosions and their effects on disks.

Masataka Aizawa (Ibaraki University), who led this research, said, “We came upon this phenomenon by chance while reanalyzing ALMA archival data. In science fiction, there are scenes where a beam is fired at something to destroy it, causing an explosion with debris flying back at the shooter. Similar things occur in real astronomical phenomena, but with greater intensity. Through this discovery, I once again realized that nature is far more complex than humans think. In future research, I hope to explore further the effects of the explosions on the formation of stars and planetary systems.”

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Releases

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Additional Information

This research has been published in The Astrophysical Journal on 4th August 2025, as Masataka Aizawa et al. “Discovery of Jet-Bubble-Disk Interaction: Jet Feedback on a Protoplanetary Disk via an Expanding Bubble in WSB 52”.

The National Astronomical Observatory of Japan (NAOJ), an ALMA partner on behalf of East Asia, published the original press release.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Contacts:

Nicolás Lira
Education and Public Outreach Officer
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236
Email: jmalusky@nrao.edu

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ALMA Reveals Hidden Structures in the First Galaxies of the Universe

A family portrait of galaxies from the CRISTAL survey. The image shows the gas traced by ALMA’s [CII] observations. Blue and green represent starlight captured by the Hubble and James Webb Space Telescopes. Credit: ALMA (ESO/NAOJ/NRAO) / HST / JWST / R. Herrera-Camus

A family portrait of galaxies from the CRISTAL survey. Red shows cold gas traced by ALMA’s [CII] observations. Blue and green represent starlight captured by the Hubble and James Webb Space Telescopes. Credit: ALMA (ESO/NAOJ/NRAO) / HST / JWST / R. Herrera-Camus

Zoom into the emission from an early galaxy observed in the CRISTAL survey. From left to right, the image shows stellar light captured by the James Webb and Hubble space telescopes, as well as the cold gas and rotation of the galaxy traced by ALMA through ionized carbon emission. Credit: ALMA / HST / JWST / R. Herrera-Camus

Artist’s illustration of CRISTAL-13. Dust-rich regions obscure newborn stars, whose energy is re-emitted at ALMA’s millimeter wavelengths. Right: young star clusters clear the dust and shine visibly in JWST and HST images. Credit: NSF/AUI/NRAO/B. Saxton

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CRISTAL survey, led from Chile, traces cold gas, dust, and stellar light in 39 galaxies just 1 billion years after the Big Bang

Astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to peer into the early Universe and uncover the building blocks of galaxies during their formative years. The CRISTAL survey — short for [CII] Resolved ISM in STar-forming galaxies with ALMA — reveals cold gas, dust, and clumpy star formation in galaxies observed as they appeared just one billion years after the Big Bang.

“Thanks to ALMA’s unique sensitivity and resolution, we can resolve the internal structure of these early galaxies in ways never possible before,” said Rodrigo Herrera-Camus, principal investigator of the CRISTAL survey, professor at Universidad de Concepción, and Director of the Millennium Nucleus for Galaxy Formation (MINGAL) in Chile. “CRISTAL is showing us how the first galactic disks formed, how stars emerged in giant clumps, and how gas shaped the galaxies we see today.”

CRISTAL, an ALMA Large Program, observed 39 typical star-forming galaxies selected to represent the main population of galaxies in the early Universe. Using [CII] line emission, a specific type of light emitted by ionized carbon atoms in cold interstellar gas, as a tracer of cold gas and dust, and combining it with near-infrared images from the James Webb and Hubble Space Telescopes, researchers created a detailed map of the interstellar medium in each system. Among the key findings, most galaxies exhibited stellar birth in large clumps, each spanning several thousand light-years, revealing how star-forming regions assemble and evolve. A subset of galaxies showed signs of rotation, indicating the early formation of disk-like structures, which are precursors to modern spiral galaxies. The [CII] emission often extended far beyond the visible stars, indicating the presence of cold gas that may fuel future star formation or be expelled by stellar winds.

“What’s exciting about CRISTAL is that we are seeing early galaxies not just as points of light, but as complex ecosystems,” said Loreto Barcos-Muñoz, co-author of the study, astronomer at the U.S. National Radio Astronomy Observatory (NRAO), and ALMA point of contact for the survey. “This project shows how ALMA can resolve the internal structure of galaxies even in the distant Universe — revealing how they evolve, interact, and form stars.”

Two galaxies in the survey stood out. CRISTAL-13 features massive clouds of cosmic dust that block visible light from newborn stars. This light is reprocessed into millimeter wavelengths detectable by ALMA, revealing structures that are entirely hidden from telescopes observing in optical or infrared wavelengths. CRISTAL-10 presents a puzzling case: its ionized carbon emission is unusually faint relative to its infrared brightness, a trait only seen in rare, heavily obscured galaxies like Arp 220 in the nearby Universe. This suggests extreme physical conditions or an unusual power source in its interstellar medium.

“These observations highlight ALMA’s potential as a time machine, allowing us to peer into the early ages of the Universe,” said Sergio Martín, Head of the Department of Science Operations at ALMA. “Programs like CRISTAL demonstrate the power of ALMA’s Large Programs to drive high-impact science. They allow us to tackle the big questions of cosmic evolution with the unprecedented depth and resolution that only a world-class observatory like ALMA can provide.”

By conducting the first systematic survey of the cold gas in early galaxies and comparing it with their stars and dust, CRISTAL offers a new window into cosmic history. The survey sets the stage for future observations that may uncover how galaxies transition from turbulent early phases to the well-structured systems we see in the local Universe. “CRISTAL provides the kind of multi-wavelength data that allows us to test and refine our theories of galaxy evolution,” said Herrera-Camus. “This is a major step toward understanding how galaxies like our Milky Way came to be.

Scientific Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Release

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Additional Information

This research was published as "The ALMA-CRISTAL survey: Gas, dust, and stars in star-forming galaxies when the Universe was ∼1 Gyr old" by Herrera-Camus et al. in Astronomy & Astrophysics.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Contacts:

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236

Email: jmalusky@nrao.edu

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

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New Super-resolution Imaging Reveals the First Step of Planet Formation after Star Birth

Artist’s impression of the distinctive substructure in a protoplanetary disk formed a few hundred thousand years after the birth of the central star. Credit: Y. Nakamura, A. Shoshi et al.

A scatter plot of bolometric temperatures and dust disk radii of the sources investigated in this study and those observed in the eDisk project. Purple, red, and yellow markings indicate disks with characteristic structures or potential ones with substructures. A bolometric temperature of 650 K corresponds to a disk around a central star that has evolved for about one million years since its formation, suggesting that characteristic substructures begin to emerge at even earlier stages. Credit: A. Shoshi et al.

A comparison of images of protoplanetary disks in the Ophiuchus star-forming region, created with super-resolution imaging with sparse modelling versus a conventional imaging method. The resolution is indicated by the white ellipse in the lower left corner of each panel, with a smaller ellipse denoting higher resolution. The white line in the lower right of each panel indicates a scale of 30 AU. The evolution stage of the central stars progresses from left to right, and from top to bottom in the same row. Credit: ALMA(ESO/NAOJ/NRAO), A. Shoshi et al.

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A research team led by Ayumu Shoshi of Kyushu University and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) revealed protoplanetary disks around protostars that had not been clearly observed in previous analyses, by employing a new imaging technique with sparse modeling on ALMA archival data. The targets were 78 disks in the Ophiuchus star-forming region. These disks composed of gas and dust that form around protostars immediately after their birth are, so to speak, the cradles of planets. The new technique revealed various characteristic disk substructures, including rings and spirals, that were previously undetectable with conventional methods. Notably, these distinctive substructures were found for a significant number of stars in their early formation stages, approximately several hundred thousand years after the star birth. This suggests the possible coevolution of stars and planets in a gas and dust rich environment, providing an important clue to understanding the process of planet formation.

Identifying the formation period of planetary systems, such as our Solar System, could be the beginning of the journey to discover the origin of life. The key to this is the unique substructures found in protoplanetary disks – the sites of planet formation. A protoplanetary disk is composed of low-temperature molecular gas and dust, surrounding a protostar. If a planet exists in the disk, its gravity will gather or eject materials within the disk, forming characteristic substructures such as rings or spirals. In other words, various disk substructures can be interpreted as “messages” from the forming planets. To study these substructures in detail, high-resolution radio observations with ALMA are required.

Numerous ALMA observations of protoplanetary disks (or circumstellar disks) have been conducted so far. In particular, two ALMA large programs, DSHARP and eDisk, have revealed the detailed distribution of dust in protoplanetary disks through high-resolution observations. The DSHARP project discovered that distinctive structures are common in circumstellar disks around 20 young stars, each exceeding one million years since the onset of star formation (see note below). On the other hand, fewer distinctive structures were found by the eDisk project that investigated disks around 19 protostars in the accretion phase (the stage where mass accretion onto the star and the disk is active). This phase occurs approximately 10,000 to 100,000 years after star birth. This suggests that disks have diverse characteristics depending on the age of the star.

Here, the question is when do substructures, the signs of planet formation, appear in disks. To find the answer, it is necessary to observe disks of a wide range of intermediate ages that have yet to be explored. However, limitations on the number of disks observable at high resolution, due to distance and observational time, make it challenging to conduct a statistically significant survey with a sufficiently large sample size.

To overcome these limitations, the research team turned to super-resolution imaging with sparse modeling. In radio astronomy, images are commonly restored based on a specific assumption to compensate for missing observation data. The imaging method employed this time reconstructs based on a more accurate assumption than the conventional approach, producing higher-resolution images even though the same observation data is used. PRIISM (Python module for Radio Interferometry Imaging with Sparse Modeling), the public software developed by a Japanese research team was used in this study. The research team utilized this new imaging technique on ALMA archival data, targeting 78 disks in the Ophiuchus star-forming region, located 460 light years from the Solar System.

As a result, more than half of the images produced in this study achieved a resolution over three times higher than that of the conventional method, which is comparable to that of the DSHARP and eDisk projects (Figure 1). Moreover, the total number of samples in this study is nearly four times larger than that of the previous two projects, significantly improving the robustness of our statistical analysis. Among the analyzed 78 disks, 27 disks were revealed to have ring or spiral structures, 15 of which were identified for the first time in this study.

The team combined the Ophiuchus sample with those of the eDisk project to conduct a statistical analysis. As a result, they found that the characteristic disk substructures emerge in disks with radii larger than 30 astronomical units (au) during the early stage of star formation, just a few hundred thousand years after a star was born (Figure 2). This suggests that planets begin to form at a much earlier stage than previously believed, when the disk still possesses abundant gas and dust (Figure 3). In other words, planets grow together with their very young host stars. Ayumu Shoshi says, “These findings, bridging the gap between the eDisk and DSHARP projects, were enabled by the innovative imaging that allows for both achieving high resolution and a large number of samples. While these findings only pertain to the disks in the constellation Ophiuchus, future studies of other star-forming regions will reveal whether this tendency is universal.”

Scientific Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Media

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Note

The evolutionary stage of a protostar is estimated using the bolometric temperature around the star. The bolometric temperature is an apparent temperature derived from the total brightness of an object across all wavelengths. A higher bolometric temperature indicates a more advanced evolutionary stage, and a temperature of 650 K suggests that approximately one million years have passed since the birth of the star.

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Additional Information

This research has been published in The Publications of the Astronomical Society of Japan on April 22, 2025, as Ayumu Shoshi et al. “ALMA 2D super-resolution imaging survey of Ophiuchus Class I/flat spectrum/II disks. I. Discovery of new disk substructures” (DOI: https://doi.org/10.1093/pasj/psaf026)

Co-researchers: Masayuki Yamaguchi (ASIAA), Takayuki Muto (Kogakuin University), Naomi Hirano (ASIAA), Ryohei Kawabe (Graduate School of Advanced Studies, SOKENDAI/National Astronomical Observatory of Japan), Takashi Tsukagoshi (Ashikaga University), and Masahiro Machida (Kyushu University)

The original press release was published by the National Astronomical Observatory of Japan (NAOJ), an ALMA partner on behalf of East Asia.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Contacts:

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236
Email: jmalusky@nrao.edu

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

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ALMA Reveals Lives of Planet-Forming Disks Press Releases ALMA Reveals Lives of Planet-Forming Disks

Artist’s concept of protoplanetary disk, like the thirty studied for the ALMA AGE-PRO survey. The lifetime of the gas within the disk determines the timescale for planetary growth. Credit: NSF/AUI/NSF NRAO/S.Dagnello

An artist’s illustration of gas disk evolution as revealed by the AGE-PRO program. The AGE-PRO program observed 30 protoplanetary disks around Sun-like stars to measure how the mass of gas disks changes with age. The top row illustrates the previously known trend: the fraction of young stars with disks declines over time. The AGE-PRO study, for the first time, shows that the median gas disk mass of the surviving disks also decreases with age. Disks younger than 1 Myr typically have several Jupiter masses of gas, but this drops rapidly to below 1 Jupiter mass in older systems. Interestingly, the surviving disks in the 1–3 Myr and 2–6 Myr age ranges appear to maintain similar median gas masses. Credit: Age-Pro collaboration, C. Agurto-Gangas

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Observations of 30 disks reshape our understanding of how gas evolves in the birthplaces of planets

An international team of astronomers has unveiled groundbreaking findings about the disks of gas and dust surrounding nearby young stars using the Atacama Large Millimeter/submillimeter Array (ALMA). These results, published in 12 papers in a special issue of The Astrophysical Journal, are part of an ALMA Large Program known as AGE-PRO (ALMA Survey of Gas Evolution of PROtoplanetary Disks).

AGE-PRO observed 30 protoplanetary disks around Sun-like stars to measure gas disk masses at different stages of evolution. The study revealed that gas and dust in these disks evolve at different rates. “AGE-PRO provides the first systematic measurements of gas disk masses and sizes across the lifetime of planet-forming disks,” said Ke Zhang, Principal Investigator of the program from the University of Wisconsin–Madison.

A protoplanetary disk surrounds its host star for several million years, during which time its gas and dust evolve and dissipate. This sets the timeline for the formation of giant planets. The initial mass, size, and angular momentum of the disk strongly influence the kind of planets that can form—whether gas giants, icy giants, or mini-Neptunes—and their potential migration paths.

ALMA’s unique sensitivity enabled the team to detect faint molecular lines, which allowed them to probe the cold gas within the disks. AGE-PRO targeted 30 disks of different ages, ranging from less than one million to over five million years old, located in three star-forming regions: Ophiuchus, Lupus, and Upper Scorpius. The survey captured key tracers of gas and dust masses, building a legacy dataset for studying the full lifecycle of planet-forming environments.

While carbon monoxide (CO) is the most widely used tracer in protoplanetary disks, AGE-PRO also employed the molecular ion N₂H⁺ to improve the accuracy of gas mass estimates. Additionally, ALMA’s sensitivity enabled the serendipitous detection of other molecular lines, including H₂CO, DCN, DCO⁺, N₂D⁺, and CH₃CN. “This is the first large-scale chemical survey of its kind, targeting 30 disks spanning a broad age range to characterize gas masses,” said John Carpenter, ALMA Observatory Scientist and co-lead of the program.

The findings reveal that gas and dust are consumed at different rates as disks age, with a distinct “swing” in the gas-to-dust mass ratio over time. Zhang explains, “The most surprising finding is that although most disks dissipate after a few million years, those that survive retain more gas than we expected. This fundamentally alters our understanding of how and when planets acquire their final atmospheres.”

Among the collaborators in AGE-PRO was a prominent Chilean team from the University of Chile, led by astrophysicist Laura Pérez, along with postdoctoral researchers Carolina Agurto and Aníbal Sierra, all of whom affiliated with the Center for Astrophysics and Associated Technologies (CATA). Pérez emphasized the value of the survey in providing a much-needed view of gas evolution: “Until now, most of what we knew about disk evolution was based on solids. With AGE-PRO, we finally have direct, consistent measurements of how the gas evolves throughout the disk’s lifetime—crucial for understanding how giant planets form.”

Carolina Agurto led the analysis of Upper Scorpius, a region known for hosting more evolved disks. Her work delivered critical insights into the final stages of these systems, showing that disks that persist longer contain significantly more gas than previously thought. Meanwhile, Aníbal Sierra focused on one of the brightest and oldest disks in the sample—2MASS J16120668-3010270—where he identified signs of two forming planets: one revealed by the surrounding dust and another inferred from gravitational perturbations. Follow-up observations with the James Webb Space Telescope (JWST) are already being planned to directly detect exoplanets.

Several undergraduate and graduate students in Chile also contributed to AGE-PRO: Benjamín Cabrera, who worked on determining stellar masses; José Mondaca, who analyzed the youngest disks in Ophiuchus; and Camila Pulgarés, who focused on the evolutionary study of dust in all 30 disks.

“The advancement of science is a truly collaborative endeavor, driven by people from different countries and backgrounds, each contributing their unique perspective to push the boundaries of discovery,” said Ilaria Pascucci, co-Principal Investigator from the University of Arizona.

Additional Information

The original press release was published by the National Radio Astronomical Observatory (NRAO) of the U.S.A., an ALMA partner on behalf of North America.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Release

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Contacts

Nicolás Lira
Education and Public Outreach Coordinator
Phone: tel:+56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Laura Pérez
Department of Astronomy, University of Chile
Santiago, Chile
Cel: +5699494640
Email: lperez@das.uchile.cl

Jill Malusky
Public Information Officer
NRAO
Phone: tel: +1 304-456-2236
Email: jmalusky@nrao.edu

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: tel: +49 89 3200 6670
Email: press@eso.org

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A Fierce Storm in a Giant-Barred Spiral Galaxy 11 Billion Years Ago

Left: Near-infrared image captured by the James Webb Space Telescope. The two galaxies at the bottom are the foreground objects. Right: Molecular gas distribution observed by ALMA. Gas accumulates at the leading side of the rotating bar structure and falls toward the center. (credit: NASA, ALMA(ESO/NAOJ/NRAO), Huang et al.).

Left: Near-infrared image of a nearby galaxy, VV114, and the background monster barred spiral galaxy J0107a at z=2.433 captured by the James Webb Space Telescope (credit: NASA). Right: Stellar and molecular gas distribution of J0107a (credit: NASA, ALMA(ESO/NAOJ/NRAO), Huang et al.).

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In the early universe, more than 10 billion years ago, numerous monster galaxies formed stars at a rate over 100 times faster than the Milky Way. Although a few galaxies undergo star formation at a similar pace even in the present-day universe, almost all of them collide or merge with other galaxies. Based on this, scientists assumed that such intense bursts of star formation in monster galaxies are also caused by substantial gas influx at their centers because of galaxy collisions or mergers, and that they evolve into giant elliptical galaxies once the gas is depleted.

Monster galaxies are far from Earth and obscured by massive amounts of dust generated by intense star formation, making them difficult to observe at optical wavelengths. Until recently, their shape and the physical process that drives such bursts of star formation remained largely unknown. However, recent infrared imaging observations with the James Webb Space Telescope have uncovered dust-veiled monster galaxies, revealing the existence of many monster galaxies with a remarkable disk structure. This prompted a new question: Why are monster galaxies that appear to be ordinary disk galaxies experiencing such intense bursts of star formation?

A research team led by Shuo Huang targeted a monster galaxy with a barred spiral structure in the Universe 11.1 billion years ago. The J0107a galaxy, located at a redshift of z=2.467, was serendipitously found in 2014, while the nearby merging galaxy VV114 was observed. The James Webb Space Telescope’s near-infrared images of VV114, released in 2023, revealed that J0107a is an exceptionally massive example of a monster galaxy, with a mass more than ten times that of the Milky Way Galaxy and a star formation rate approximately 300 times that of the Milky Way. Even more surprisingly, J0107a has a perfect barred spiral structure, one of the largest and most distinct of any galaxy in this cosmic epoch. The shape looks more like modern barred spiral galaxies than any previously observed monster galaxies. While more information on gas kinematics is needed to explore the factors behind J0107a's intense star formation, spectroscopic observations of a dust-covered galaxy are incredibly challenging, even with the James Webb Space Telescope.

The research team then used ALMA to observe the emission lines of carbon monoxide and neutral carbon atoms and discovered that J0107a closely resembles modern barred spiral galaxies, such as the Milky Way, in terms of the shape of its bar structure as well as the distribution and movement of the associated gas. On the other hand, the team also found that while the proportion of gas in the bar structure of a modern galaxy is less than 10% of the total mass, that of J0107a is very high at around 50%. The data shows that J0107a's bar structure, which consists of stars and gas with a mass far greater than that of modern galaxies, stirs up the disk, creating a gas flow at a speed of several hundred kilometers per second over a radius of 20,000 light-years around the center of the galaxy, which is equivalent to the distance from the center of the Milky Way to the Solar System. Some of this gas falls into the galaxy's center, resulting in intense star formation. No previous theoretical studies of galaxy formation predicted the existence of a monster galaxy with such a bar structure.

This is the first successful direct observation of a burst of star formation induced by gas inflow from a bar structure in the early universe. The conventional theories of monster galaxy formation and evolution assumed that intense star formation occurs due to galactic collisions and mergers or gravitational instability in their disks, turning them into elliptical galaxies over hundreds of millions of years. Meanwhile, J0107a is assumed to have developed a shape resembling a modern barred spiral galaxy while retaining the extreme physical properties of a monster galaxy over hundreds of millions of years in the early universe, just 2.6 billion years after the Big Bang. The detailed data on gas distribution and kinematics obtained from this observation will provide essential clues to the origin of monster galaxies and inform research into the formation and evolution of bar structures in other galaxies, as we are witnessing the bar structure formation process in the early universe.

Shuo Huang, the research team's leader, says, "The substantial amount of gas required for the growth of giant galaxies is supplied by galactic mergers or inflows from the cosmic web. While no sign of a galactic merger exists, a large gas disk has been detected around J0107a. This gas disk has a diameter of approximately 120,000 light years, which is twice the diameter of the galaxy's main body, visible as stars, and its motion roughly follows that of the galaxy itself. Based on this, we assume it was created from a large amount of gas spiraling toward the galaxy from the cosmic web1. This is a new picture of a monster galaxy, in which a disk galaxy is formed from a cosmic-scale gas flow, followed by the emergence of a bar structure during the galactic evolution, leading to rapid galactic-scale gas flows and bursts of star formation. We will continue our observational studies with ALMA to investigate this further."

Science Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Release

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Notes

1. These gas flows are theoretically predicted and called "cold streams."

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Additional Information

This research was published in Nature on May 21, 2025, by Shuo Huang et al., "Large gas inflow driven by a matured galactic bar in the early Universe" (DOI: 10.1038/s41586-025-08914-2).

Grants-in-Aid support this research from the Japan Society for the Promotion of Science (KAKENHI: Nos. JP22H04939, JP23K20035, JP24H00004) and the ALMA Joint Scientific Research Program (No. 2024-26A).

The National Astronomical Observatory of Japan (NAOJ), an ALMA partner on behalf of East Asia, published the original press release.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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ALMA Inspires New Models for the Evolution of Planet-Forming Disks

This image shows the 15 brightest protoplanetary disks in Ophiuchus (observed by the ODISEA project and DSHARP), in which one can observe the presence of rings and grooves of different sizes that indicate the presence of bodies in formation. Credit: Orcajo, S. et al. (2025)

The top panel shows the models of each evolutionary stage of planet-driven substructures proposed by Cieza et al. (2021). The bottom panels show authentic ALMA images of disks representing each stage. Credit: Orcajo, S. et al. (2025)

This table presents the 15 protoplanetary disks considered by the ODISEA project (ten disks in the Ophiuchus system observed by ODISEA, and five observations from the DSHARP survey) and their corresponding classifications (in the top row) according to the evolutionary sequence proposed by Cieza et al. (2021). Credit: Orcajo, S. et al. (2025)

This video showcases the comparison between the structure of the protoplanetary disks predicted in the simulations and the disks observed in ODISEA. Credit: Orcajo, S. et al. (2025)

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By combining ALMA observations and simulations, the ODISEA team traces how planets may form and reshape their disks

Ever since ALMA captured the striking image of HL Tau in 2014, revealing intricate rings and gaps in a disk around a newborn star, astronomers have sought to understand how such complex structures could emerge so early. The surprise deepened in 2018 when the DSHARP survey showed these features were common across many protoplanetary disks, sparking debate over whether planets were behind them.

Now, using data from the Atacama Large Millimeter/submillimeter Array (ALMA) and advanced simulations, a research team led by Santiago Orcajo from the Instituto de Astrofísica de La Plata in Argentina (CONICET and Universidad Nacional de La Plata) in collaboration with researchers from the YEMS Millennium Nucleus (Chile) has presented a new model that traces the evolution of these disks through five distinct stages. The results strongly support a planet-driven origin of these substructures and offer new insights into how planets interact with the disks in which they form.

Protoplanetary disks are the birthplaces of planetary systems, and understanding their evolution is crucial for comprehending planet formation processes. The surprising image of HL Tau captured by ALMA in 2014 prompted astronomers to ask: How could a young protostar system already show such well-defined rings and gaps?

In 2018, the Disk Substructures at High Angular Resolution Project (DSHARP) showed that rings and gaps are widespread in most protoplanetary disks. These findings further challenged our understanding of the planet formation process and generated significant skepticism about their planetary origin.

By using ALMA observational data and PlanetaLP and Radmc-3D simulations, an international scientific team led by Orcajo has now been able to reproduce each one of the stages of the evolutionary sequence proposed by the Ophiuchus Disk Survey Employing ALMA (ODISEA) project in 2021, providing strong evidence in support of the planet formation scenario. This could also confirm the mechanisms by which giant planets affect dust dynamics and the formation of substructures such as gaps and rings.

"In science, we look for patterns and similarities and search for the simplest explanation that might account for many observations. We realized that the disks could be organized in several groups, and each group showed distinct properties that may be linked to distinct stages of a single underlying process: planet formation," said Lucas Cieza about the evolutionary sequence proposed in 2021.

The ODISEA sequence proposes categorizing protoplanetary disks into five distinct stages, each characterized by specific features related to planet formation. Observations indicate that young disks (Stage I¹) exhibit minimal substructure. At the same time, as protoplanets grow, they begin to carve gaps and create rings (Stages II² and III³) due to their gravitational interactions with the surrounding material. These gaps indicate the presence of giant planets, which can form within approximately 1 million years or less at significant distances from their host stars. Large central dust cavities become clear as the disks evolve (Stages IV⁴ and V⁵), marking advanced evolution due to the interactions between the disk and forming planets.

Giant planets significantly influence dust dynamics within protoplanetary disks by creating gaps and pressure bumps that alter the distribution of gas and dust. As a giant planet forms, it generates a deep gap in the disk, redistributing gas density and accumulating millimeter-sized dust at the edges of these gaps. This process drives the evolution of dust within the disk and facilitates the formation of ring-like structures. Simulations using models like PlanetaLP have demonstrated how these gravitational effects lead to observable features in the disk, which can be directly compared with high-resolution ALMA observations.

"Working on this study, we found that the PlanetaLP evolution simulation code allows us to find possible configurations of planets (of different masses and orbits) that form disks with gap and ring structures after thousands of years of evolution, like those we see with ALMA observations. In several tests, we noticed that planets' existence extends the inner disk's lifetime. While the possibilities are endless, planets affect the disk morphology. The first motivation was to recreate the Elias 2-24 disk from simulations. Still, we then realized that our code could reproduce the entire evolutionary sequence," concluded the main author, Santiago Orcajo.

The implications of this work are significant, especially for interpreting the original HL Tau image. "This kind of study is deeply relevant to ALMA because it supports one of the array's most iconic discoveries," said Antonio Hales, an ALMA astronomer and co-author of the study. "By showing that these structures are likely caused by forming planets, we're not just observing disks—we're watching the process of planet formation unfold in real-time. ALMA becomes not just a disk imager, but a powerful tool for planet detection."

The findings also highlight current challenges in explaining how massive planets can form so quickly and far from their host stars. As research continues, detecting minor, rocky planets in fainter disks remains a promising and ambitious goal to understand the origins of planetary systems like our own.

Scientific Paper

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Releases

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Additional Information

The results of the study are published in the Astrophysical Journal Letters in the following scientific article by Orcajo et al.: "The Ophiuchus DIsk Survey Employing ALMA (ODISEA): A Unified Evolutionary Sequence of Planet-Driven Substructures Explaining the Diversity of Disk Morphologies."

The research team is composed of young researchers from the Institute of Astrophysics of La Plata (CONICET and National University of La Plata, Argentina) and the Millennium Nucleus for the Study of Young Exoplanets and their Moons (YEMS, Chile), a research center funded by the National Agency for Research and Development of Chile (ANID) through its Millennium Scientific Initiative program, and housed at the Diego Portales University, the University of Santiago de Chile, the Pontifical Catholic University of Chile and the University of Concepción.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

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Foot Notes

1. Stage I: Very young disks with shallow or no obvious substructures, corresponding to an epoch in which protoplanets are not massive enough to carve noticeable gaps in the disks. ↩︎
2. Stage II: Disks with relatively narrow, but clear gaps and rings, indicating the growth of protoplanets ↩︎
3. Stage III: A rapid widening of the gaps due to the sudden growth in the mass of some planets when they acquire their gaseous envelopes. This stage includes the rapid accumulation of dust at the outer edges of the gaps (the inner rims of the outer disks) due to the strong “pressure bumps” caused by the giant planets that recently formed, which stops the inward drift of dust. ↩︎
4. Stage IV: Dust filtration at the edges of the cavities, resulting in dust-depleted inner disks. The millimeter dust from the outer disks efficiently drifts in and accumulates at the edges of the gaps. ↩︎
5. Stage V: Eventually, the dusty inner disks drain completely onto the stars, and the outer disks become narrow rings (or collections of narrow rings). ↩︎

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Contacts:

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago - Chile
Phone: +56 2 2467 6519
Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236
Email: jmalusky@nrao.edu

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

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ALMA Discovers Oxygen in Most Distant Known Galaxy Press Releases ALMA Discovers Oxygen in Most Distant Known Galaxy

This image shows the location in the night sky of the galaxy JADES-GS-z14-0, an extremely tiny dot in the Fornax constellation. As of today, this is the most distant confirmed galaxy we know of. Its light took 13.4 billion years to reach us and shows the universe's conditions when it was only 300 million years old. The inset of the image shows a close-up of this primordial galaxy as seen with the Atacama Large Millimeter/submillimeter Array (ALMA).

The inset is overlaid on an image taken with the NASA/ESA/CSA James Webb Space Telescope. The two spectra shown here result from an independent analysis of ALMA data by two teams of astronomers. Both found an emission line of oxygen, making this the most distant detection of oxygen when the universe was only 300 million years old. ALMA (ESO/NAOJ/NRAO)/S. Carniani et al./S. Schouws et al./JWST: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA).

This is an artist’s impression of JADES-GS-z14-0, which as of today is the most distant confirmed galaxy. Galaxies in the early Universe tend to be clumpy and irregular. Supernova explosions in this galaxy would have spread heavy elements forged inside stars, like oxygen, which has been now detected with the Atacama Large Millimeter/submillimeter Array (ALMA).

This artist’s animation shows JADES-GS-z14-0, the most-distant galaxy confirmed to date. We see this galaxy as it was when the Universe was less than 300 million years old, about 2% of its present age. Such galaxies were thought to be too young to be ripe with heavy elements, but the discovery of oxygen by two teams of astronomers suggest this is not the case. Instead, as this recreation shows, JADES-GS-z14-0 must have had multiple generations of stars being born and dying as supernovae, producing and leaving behind heavy elements like oxygen. This element has now been detected thanks to the extreme sensitivity of the Atacama Large Millimeter/submillimeter Array (ALMA). Credits: ESO/M. Kornmesser.

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Two different scientific teams have detected oxygen in JADES-GS-z14-0. The breakthrough, reported in two separate studies, was made possible thanks to the Atacama Large Millimeter/submillimeter Array (ALMA). This record-breaking detection makes astronomers rethink how quickly galaxies formed in the early universe.

Discovered in 2024, JADES-GS-z14-0 is the most distant confirmed galaxy ever found. Its light took 13.4 billion years to reach us, meaning we see it as when the universe was less than 300 million (about 2% of its present age). The new oxygen detection with ALMA suggests the galaxy is more chemically mature than expected.

"It is like finding an adolescent where you would only expect babies," says Sander Schouws, a PhD candidate at Leiden Observatory, Netherlands, and first author of the Dutch-led study. "The results show the galaxy has formed and matured very rapidly, adding to a growing body of evidence that the formation of galaxies happens much faster than expected."

Galaxies usually start their lives with plenty of young stars, which are made mostly of light elements like hydrogen and helium. As stars evolve, they create heavier elements like oxygen, which get dispersed through their host galaxy after they die. Researchers thought that, at 300 million years old, the universe was still too young to have galaxies ripe with heavy elements. However, the two ALMA studies indicate that JADES-GS-z14-0 has about 10 times more heavy elements than expected.

"I was astonished by the unexpected results because they opened a new view on the first phases of galaxy evolution," says Stefano Carniani of the Scuola Normale Superiore of Pisa, Italy, and lead author on the second paper. "The evidence that a galaxy is already mature in the infant Universe raises questions about when and how galaxies formed."

The oxygen detection has also allowed astronomers to make their distance measurements to JADES-GS-z14-0 much more accurate. "The ALMA detection offers an extraordinarily precise measurement of the galaxy's distance down to an uncertainty of just 0.005%. This level of precision — analogous to being accurate within 5 cm over 1 km — helps refine our understanding of distant galaxy properties", adds Eleonora Parlanti, a PhD student at the Scuola Normale Superiore of Pisa.

"While the galaxy was originally discovered with the James Webb Space Telescope (JWST), it took ALMA to confirm and precisely determine its enormous distance," says Associate Professor Rychard Bouwens, a team member at Leiden Observatory.". This shows the amazing synergy between ALMA and JWST to reveal the formation and evolution of the first galaxies."

Gergö Popping, an European Southern Observatory (ESO) astronomer at the European ALMA Regional Centre who did not participate in the studies, says: "I was really surprised by this clear detection of oxygen in JADES-GS-z14-0. It suggests galaxies can form more rapidly after the Big Bang than previously thought. This result showcases the important role ALMA plays in unraveling the conditions under which the first galaxies in our universe formed."

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< Additional information

The results of the studies are published in the following papers:

• Carniani et al. "The eventful life of a luminous galaxy at z=14: metal enrichment, feedback, and low gas fraction?"

• Schouws et al. “Detection of [OIII]88μm in JADES-GS-z14-0 at z=14.1793”
  

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The European Southern Observatory (ESO), an ALMA partner on behalf of Europe, published the original press release.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member Sta

tes, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/Press Releases

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Contacts:

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago - Chile
Phone:+56 2 2467 6519

Cel: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: press@eso.org

Jill Malusky
Public Information Officer
NRAO
Phone: +1 304-456-2236
Email: jmalusky@nrao.edu

Yuichi Matsuda
ALMA EA-ARC Staff Member
NAOJ
Email: yuichi.matsuda@nao.ac.jp

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