Bonfire series planned for Apple is no longer proceeding at the streaming service, ending the latest attempt to transform Tom Wolfe’s The Bonfire of the Vanities into an episodic television drama.

The project had assembled a notable creative team. David E. Kelley was attached to write and executive produce, while The Batman director Matt Reeves was expected to direct the eight-episode adaptation and serve as an executive producer through his 6th & Idaho Productions company.

Warner Bros. Television was producing the series, with Sarah Geismer representing 6th & Idaho and Matthew Tinker participating through David E. Kelley Productions.

According to industry reports, Apple and the creative team were not aligned on the direction of the adaptation. Kelley was also reportedly dissatisfied with how the development process had been handled. The exact source of the disagreement has not been disclosed.

Apple has not announced the project as a formal cancellation, and it never received a public premiere date or cast. Its departure from Apple instead ends one stage of development while leaving Warner Bros. Television with the possibility of taking the adaptation elsewhere.

Apple Ends the Project After Four Months

News of the Bonfire series first emerged in April 2026. Kelley was expected to write the adaptation after working with Apple on Presumed Innocent and Margo’s Got Money Troubles, while Reeves would direct after completing his existing film commitments.

The partnership appeared well suited to a complicated literary adaptation. Kelley has extensive experience turning novels into television dramas, including Big Little Lies, The Lincoln Lawyer, Nine Perfect Strangers, Presumed Innocent, and Wolfe’s A Man in Full.

Reeves brought a different set of strengths. His work on The Batman, Dawn of the Planet of the Apes, War for the Planet of the Apes, and Cloverfield demonstrated his ability to handle large casts, morally compromised characters, and cities presented as active elements of the story.

The arrangement also connected Warner Bros. Television with Apple’s preference for recognizable creators and established literary properties. Wolfe’s novel offered a prestigious title, a large ensemble, and a view of New York society that could support a limited-series structure.

The development reportedly lasted only a few months before the creative relationship broke down. No actors had been announced, and there was no indication that cameras were close to rolling.

The absence of production activity makes the development easier to stop than a commissioned series with actors, sets, and crews already under contract. It also means Apple can leave the project without abandoning completed episodes or disrupting a release calendar.

Development Never Reached Production

A television project entering development is not the same as a series receiving a complete production order. Writers can prepare scripts, directors can become attached, and studios can negotiate with a streaming service before a final budget or filming commitment is approved.

The Bonfire of the Vanities was widely discussed as an eight-episode Apple adaptation, but Apple never unveiled it through its official press service. The project did not appear with a cast, production date, first-look image, or planned release window.

That distinction makes “stalled” more accurate than suggesting that Apple canceled a finished series. The adaptation remains intellectual property controlled through its rights and production arrangements, but the version developed for Apple has stopped advancing.

Creative alignment can cover several areas, including tone, period setting, episode structure, budget, casting, and how closely a project follows its source. None of those issues has been identified publicly as the specific cause of the disagreement.

The source material presents difficult choices. Wolfe wrote the novel as a detailed portrait of 1980s New York, with Wall Street, tabloid journalism, city politics, race, class, and personal ambition colliding around a single incident.

An adaptation could preserve that period or move the story into a contemporary financial and media environment. Keeping the 1980s setting would retain the social ecosystem Wolfe observed, while modernization would require substantial changes to technology, journalism, policing, politics, and the financial industry.

Reports of creative differences do not establish which approach Apple, Kelley, Reeves, or Warner Bros. preferred. Until one of the parties discusses the project, the disagreement remains undefined.

A Difficult Novel to Translate

Published in 1987 after being serialized in Rolling Stone, The Bonfire of the Vanities follows Sherman McCoy, a wealthy bond trader who considers himself a “Master of the Universe.”

McCoy’s protected life begins collapsing after he and his mistress take a wrong turn into the Bronx. Their encounter with two young Black men ends in a hit-and-run, creating an opportunity for journalists, attorneys, politicians, activists, and social climbers to exploit the case.

The novel spreads its attention across several communities and institutions. Its satire depends on the reader observing how each group manipulates the incident while claiming moral authority. That scope gives television more room than a feature film, but it also requires precise control of perspective and tone.

Brian De Palma directed the previous film adaptation, released by Warner Bros. in 1990. Tom Hanks played Sherman McCoy alongside Melanie Griffith, Bruce Willis, Morgan Freeman, Kim Cattrall, and F. Murray Abraham.

Despite the cast and an estimated production budget of approximately $47 million, the film earned about $15.6 million domestically. Critics objected to its casting, tonal decisions, and changes to Wolfe’s characters.

The difficult production later became the subject of Julie Salamon’s The Devil’s Candy, a detailed account of how an expensive adaptation made by accomplished filmmakers deteriorated through compromises and conflicting decisions.

The film’s reputation has followed every subsequent effort to revisit Wolfe’s novel. A television version has frequently been proposed as a better format because it can preserve more characters, institutional detail, and social context.

Amazon began developing an eight-episode adaptation in 2016 with Chuck Lorre and Warner Bros. Television. That version was intended to update the story while approaching it through themes of race, class, politics, and media. It never entered production.

Apple’s attempt therefore becomes another chapter in a long development history rather than the first revival since De Palma’s film.

The Kelley Relationship May Continue

The collapse of this project does not necessarily end David E. Kelley’s relationship with Apple. His adaptation of Presumed Innocent became a major drama for the service, while Margo’s Got Money Troubles expanded his work with the company into comedy-drama.

Large producers and streaming services regularly continue working together after deciding against an individual project. Each adaptation has its own creative, financial, and scheduling demands.

The reported dissatisfaction does introduce uncertainty around whether Kelley would remain involved if Warner Bros. Television places the series with another distributor. Reeves’ position is similarly unknown, particularly because directing all eight episodes would require a substantial scheduling commitment.

Apple can continue expanding its collection of literary adaptations without Bonfire. Its existing slate includes projects derived from novels, nonfiction books, short stories, podcasts, and magazine reporting, often with established filmmakers receiving considerable creative control.

The decision also illustrates how selective Apple can be before production. Projects in development may attract prominent writers and directors without ever becoming Apple Originals available to subscribers.

Warner Bros. Television remains attached as the studio behind the adaptation, giving it a potential route to another streaming service or network. No new buyer, revised creative team, or timetable has been reported for The Bonfire of the Vanities.

The post Bonfire Series Stalls at Apple After Creative Split appeared first on AppleMagazine.

Astronomers searching for extraterrestrial intelligence have traditionally focused on a specific, narrow band of the radio spectrum. However, a new survey presented at the Royal Astronomical Society‘s National Astronomy Meeting (NAM2026) in Birmingham suggests that this approach may overlook a significant portion of the available frequencies.

The frequencies most often investigated by SETI (Search for Extraterrestrial Intelligence) programs are those between 1.42 and 1.66 GHz. This range, known as the ‘water hole’, is situated between the natural radio emissions of hydrogen and hydroxyl, the two molecules that make up water. Astronomers have regarded this quiet section of the spectrum as a reasonable place for interstellar communication, because any civilization acquainted with these molecules would probably also decide to send and receive signals in search of in that specific region.

Louisa Mason, who is carrying out research as a PhD student at the University of Manchester, focused on investigating frequencies outside the water hole range. To carry out the first SETI survey with that telescope, she used archived data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. She analyzed data originally collected for other astronomical studies instead of requesting new observation time.

Hunting for Signals in Unclaimed Territory

Mason focused on two narrow frequency bands in the ALMA Band 3 data, looking for narrowband signals that might be the result of technology rather than natural astrophysical origins. In the four observations that she examined, she did not discover any candidates for technosignatures above her detection threshold.

“For decades, SETI searches have concentrated on a relatively small part of the radio spectrum. We wanted to ask what might happen if we looked somewhere very different,” Mason said. “The millimetre and submillimetre radio bands remain almost completely unexplored for SETI, so this is really about opening up a new area of parameter space to search.”

A lack of results does not rule out the possibility of alien transmitters. It only means that none appeared in this specific region of the sky and frequency range. Mason describes the survey as a proof of concept, showing that high-frequency telescopes like ALMA could play a much larger role in future SETI efforts.

A Much Bigger Haystack Than Anyone Realized

The research also revealed a gap in how astronomers count the stars they have actually examined. Each time a telescope observes a single target, it also collects light from many other stars in the same field of view. Researchers refer to this as “stellar bycatch.”

Previous SETI surveys have made this bycatch estimate based on the Gaia catalog, which is the European Space Agency‘s survey of the stars. However, Gaia has certain limitations such as its magnitude cutoffs, uncertainties when measuring distant stars, and difficulties in crowded areas. To overcome these limitations, Mason used the Besançon Galactic Model, a simulation of the Milky Way’s stellar population that includes stars that are too faint or too far away for Gaia to detect.

When Mason applied the model to a previous survey of 1,327 telescope observations, the estimated number of stars observed increased from about 288,000 with Gaia to over 6.1 million with the galactic simulation.

“One of the most exciting things about this work is realizing that we’ve surveyed many more stars than initially thought,” Mason said. “Even a very small observation can contain a huge number and diversity of stars that we might never have intended to study. By combining high-frequency observations with galactic simulations, we can better understand exactly what we’ve searched and where we should look next.”

Recommendations for SETI

Mason carried out this research in collaboration with Professor Michael Garrett, Dr. Andrew Siemion, and Dr. Kelvin Wandia. The team argues that expanding both the radio frequencies searched and the number of stars included could reduce the influence of human assumptions on SETI strategies. Whether these broader searches will detect technosignatures missed by traditional water-hole surveys remains unknown.

Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.

Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.

Title: MAGAZ3NE: Confirming Dust Deficiency and Quiescent Nature of Ultramassive Galaxies at 3 < z < 4 with ALMA Observations
Authors: Wenjun Chang et al.
First Author’s Institution: University of California, Riverside
Status: Published in ApJ

Distant galaxies offer a unique window into how stars, gas, and dust evolve over cosmic time. Tracing this evolution requires understanding not only how galaxies form, but also how and when they stop forming stars, a process known as quenching. Understanding how, when, and why galaxies quench is a fundamental question in astrophysics, and one that requires observations of star-forming, quenching, and fully quenched galaxies alike. Unfortunately, one complication is that identifying truly quenched galaxies is challenging: galaxies that appear “dead” may instead be actively forming stars, hidden behind a thick veil of dust.

In today’s article, the authors use observations from the Atacama Large Millimetre/submillimetre Array (ALMA) to investigate five ultramassive galaxies at redshifts, z, between 3 and 4, and ask a deceptively simple question: are these massive red galaxies genuinely quenched, or are they secretly forming stars behind the scenes?

Meet the Suspects: Ultramassive Galaxies at the Edge of Cosmic Noon

The five galaxies in this study are drawn from the Massive Ancient Galaxies at z > 3 NEar-infrared (MAGAZ3NE) survey, which targets some of the most massive galaxies known at early cosmic times. All five have stellar masses exceeding 100 billion solar masses and have been confirmed at z > 3. At these redshifts, we are observing the galaxies as they were when the universe was less than 2 billion years old. This is just before an epoch known as cosmic noon, when star formation across the universe reached its peak.

These galaxies also benefit from extensive multiwavelength observations from a range of observatories, including the ground-based Visible and Infrared Survey Telescope for Astronomy and the Spitzer Space Telescope. By combining imaging across wavelengths from the ultraviolet to the near-infrared, astronomers can measure the “colours” of galaxies and use these colours to infer the galaxies’ star-forming activity.

Galaxies that have quenched their star formation are dominated by older stellar populations, which makes them appear red (hence why they are often referred to as “red and dead” galaxies). However, dust can redden galaxies in a similar way by absorbing blue light and re-emitting it at longer wavelengths — meaning that a dusty, star-forming galaxy can easily masquerade as a quenched one. To uncover any hidden star formation, the authors turn to ALMA to search for far-infrared dust emission. The sample of galaxies investigated with ALMA is shown in Figure 1.

ALMA on the Scene

ALMA observes light at sub-millimetre wavelengths, which at these redshifts traces emission from star-forming regions that are obscured by dust. Of the five ultramassive galaxies in this sample, only one is detected with ALMA. Even when the remaining four galaxies are stacked together, no dust emission is recovered, indicating that if any dust is present, it must be extremely faint.

To better quantify what these ALMA non-detections imply, the authors perform spectral energy distribution fitting (see a recent overview bite on spectral energy distribution fitting) using the Code Investigating GALaxy Emission, or CIGALE, a code that enforces energy balance between absorbed starlight and dust emission to estimate physical properties such as a galaxy’s star formation rate and dust content. With the ALMA constraints included, all five galaxies are found to lie more than 10 times below the star-forming main sequence. Even the single ALMA-detected galaxy remains formally quenched, showing only weak residual star formation.

In other words, these galaxies really are dead (or at least extremely dormant).

Extremely Dust-Poor Galaxies

The spectral energy distribution fitting also allows the authors to measure how much dust these galaxies contain relative to their stellar mass. This ratio provides a simple but powerful way to assess how much interstellar material remains in a galaxy — and therefore how much fuel is left for future star formation.

Three of the five ultramassive galaxies have ratios of M_dust/M_star < 10^-4 (Figure 2), placing them among the most dust-poor quenched galaxies confirmed at z > 3. The lone galaxy detected by ALMA contains slightly more dust, with M_dust/M_star = 10^-3, but even this is far below what would be expected for an actively star-forming galaxy. For comparison, typical star-forming galaxies at similar stellar masses host more than 100 times more dust.

These results raise important questions about how galaxies can become ultramassive, quenched, and nearly dust-free within the first two billion years of cosmic history.

For now, ALMA has delivered a clear answer to the question of “dead or in disguise?”: at least some candidate ultramassive galaxies in the early universe really are quenched, and they are strikingly dust poor. By ruling out the dusty impostor scenario, this study shows that deep ALMA observations can cleanly distinguish genuinely quenched galaxies from dusty star-forming ones, even at the highest stellar masses and earliest cosmic times. How these galaxies lost their dust remains an open question, but one thing is clear: by the time cosmic noon arrived, some galaxies had already finished forming stars and quietly faded into dormancy.

Original astrobite edited by Viviana Cáceres.

About the author, Lucie Rowland:

I’m a fourth (and final!) year PhD student at Leiden Observatory in the Netherlands, studying massive, star forming galaxies in the early universe with ALMA and JWST. It’s a really exciting time to be interested in astronomy, so I hope to make groundbreaking new research more accessible!

The post Distant Galaxies: Dead or in Disguise? appeared first on AAS Nova.

JCMT0402-0424, a dusty starburst galaxy around 11 billion light-years away, is the strongest candidate yet for the source of the high-energy neutrino event IC 210922A, according to a team of astronomer led by Yuji Urata of MITOS Science Co.

The post Astronomers Trace Elusive High-Energy Neutrino to Star-Forming Galaxy in Early Universe appeared first on Sci.News: Breaking Science News.

After a 50-year search, astronomers have uncovered evidence that Sagittarius A* -- the 4.3-million-solar-mass black hole that resides at the center of our Milky Way Galaxy -- is blowing a hot cosmic wind into its surroundings, carving out a giant cavity near the Galaxy’s heart.

The post Astronomers Finally Find Milky Way’s Missing Black Hole Wind appeared first on Sci.News: Breaking Science News.

How do massive galaxies form and evolve? A recent study traces the stellar and dust distributions across evolutionary phases of massive galaxies to better understand how massive dusty star-forming galaxies fit into the picture.

Dusty Massive Galaxies

Massive galaxies, like the Milky Way or even larger, undergo phases of active star formation and quiescent phases of inactivity, but exactly how these galaxies evolve through these stages is not yet fully understood. Dusty star-forming galaxies, which are undergoing a period of intense star formation and shrouded in dust, might be the missing evolutionary step between star-forming and quiescent phases of massive galaxy evolution. 

Currently, the leading explanation for massive galaxy formation and evolution is inside-out growth — star formation and quenching start in the inner regions of a galaxy and progress outward. However, it’s not clear whether dusty star-forming galaxies also follow the favored inside-out pathway, or if they instead proceed outside-in, first growing their disks and then assembling a central bulge.

The spatial distribution (or morphology) of the stars and dust within dusty massive galaxies can help us trace their evolution. Thanks to high-resolution observations from JWST and the Atacama Large Millimeter/submillimeter Array (ALMA), researchers can now directly compare the morphologies of distant star-forming, quiescent, and dusty galaxies during the height of our universe’s star formation. Filling this gap will reveal how dusty star-forming galaxies may connect star-forming and quiescent galaxies in massive galaxy evolution.

Multiwavelength Morphological Comparisons

To directly compare the star and dust morphologies across massive galaxies, Sarah Bodansky (University of Massachusetts, Amherst) and collaborators selected a sample of 33 dusty star-forming galaxies from the GOODS-ALMA 2.0 survey that searched the sky for 1.1-mm dust emission as well as star-forming and quiescent comparison samples drawn from JWST observations. Combining the ALMA survey data with JWST imaging, the authors studied the rest-frame optical (stars) and rest-frame near-infrared (dust) morphologies of dusty, star-forming, and quiescent galaxies at redshifts around cosmic noon (a few billion years after the Big Bang).

When comparing optical morphologies, the authors found that dusty star-forming galaxies and typical star-forming galaxies had similar distributions, but their near-infrared morphologies showed clear differences. Dusty galaxies tended to show more compact near-infrared emission, with dust tracing their stellar populations and more concentrated in the galaxies’ central regions. Though clearly different from star-forming galaxies, the authors noted striking similarities between the near-infrared morphologies of the dusty star-forming and quiescent galaxies, especially within their centers.

All of these properties suggest that dusty star-forming galaxies have built up stellar mass and dust in their cores, potentially forming a central bulge first and supporting an inside-out model of massive galaxy growth. This points to dusty star-forming galaxies as possible direct progenitors of early massive quiescent galaxies, hanging onto their last bit of star formation before becoming quiet as well. While this study morphologically distinguishes dusty galaxies from their star-forming and quiescent counterparts, future spectroscopic studies comparing the kinematics of these populations and investigations of molecular gas distributions are necessary to better pin down the evolutionary connection between star-forming, dusty, and quiescent massive galaxies.

Citation

“JWST+ALMA Reveal the Buildup of Stellar Mass in the Cores of Dusty Star-forming Galaxies at Cosmic Noon,” Sarah Bodansky et al 2026 ApJ 1001 235. doi:10.3847/1538-4357/ae4f64

The post Hints for Massive Galaxy Evolution from Dusty Star-Forming Galaxies appeared first on AAS Nova.

By piecing together observations from dozens of radio telescopes in Chile, planetary scientists recently completed the first-ever map of Callisto’s emission at millimeter wavelengths.

Old and Cold

In striking contrast to Io’s frenzied volcanism and Europa’s cracking ice shell, Jupiter’s moon Callisto is much quieter and colder than its Galilean siblings. Though a liquid water ocean hypothetically sloshes beneath its frigid surface, it’d be hard to infer that just by looking at the moon. Callisto’s terrain is ancient, static, and bears the scars of the millennia of exposure to space. There are no volcanoes, plate tectonics, or any other features to disturb what researchers call “evolved ruins” of the numerous craters. These have names like Valhalla, Asgard, and Lofn, since Callisto’s geologic features are named after settings and characters in Norse mythology to further reinforce their freezing existence.

This never-reset canvas makes Callisto an ideal laboratory for studying the long-term effects of asteroid impacts, dust accumulation from nearby natural satellites, and other processes that modify a planetary surface over time. One way to infer the composition and structure of the first few meters of material is to observe the way the temperature changes over the course of a day. For example, ice and rock respond differently to temperature changes; similarly, small-grains of either material warm up and cool down at different speeds than their larger-grain counterparts.

In theory, planetary scientists can measure the temperature of a moon by noting how bright each patch of its surface appears in millimeter-wavelength observations. However, this is easier said than done, as only a handful of telescopes are capable of seeing Callisto as anything more than a fuzzy blob at those wavelengths. Back in 2016–2017, planetary scientists used the Atacama Large Millimeter/submillimeter Array (ALMA), a radio interferometer in Chile, to attempt the challenging feat of making a map of Callisto’s surface.

Mapping from Afar

A team led by Maria Camarca, California Institute of Technology, just finished churning through all of the data and assembling their map of Callisto’s temperature residuals. Though the final spatial resolution was at best a few hundred kilometers, meaning a comparable map of Earth would blur all of New England together, this represents the most detailed thermal map of Callisto yet. The map was detailed enough to easily spot the largest craters, and several impact craters including Valhalla stood out as being 3–5K colder than all of the surrounding terrain. The team spotted another anomalously cold region that coincides with the location of maximum carbon dioxide gas density recently seen with JWST.

The team also found that their data could not be explained by a simple model for Callisto’s surface that assumed one dominant material and structure. Instead, their images were better explained by more complex simulations that use two different thermal inertias. Though they are not sure yet why this may be, it is clear that Callisto, often overlooked compared to its flashier siblings, is a complex world worthy of further study. Luckily, the upcoming Jupiter Icy Moons Explorer mission and ALMA’s Wideband Sensitivity Upgrade will bring new knowledge of Callisto’s ancient surface.

Citation

“A Multifrequency Global View of Callisto’s Thermal Properties from ALMA,” Maria Camarca et al 2025 Planet. Sci. J. 6 183. doi:10.3847/PSJ/ade7ee

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Protoplanetary disks, the sites of planet formation around young stars, are rich and complex objects. An in-depth investigation of 15 protoplanetary disks has recently been published in a Focus Issue of the Astrophysical Journal Letters. This investigation leveraged the exquisite resolution and sensitivity of the Atacama Large Millimeter/submillimeter Array (ALMA), a moveable network of 66 radio dishes in the Atacama Desert in Chile.

Featuring high-resolution observations of multiple gas species, updated image processing techniques, and state-of-the-art modeling, the exoALMA project examines the early stages of planet formation, when protoplanets embedded within dusty disks induce rings, gaps, spirals, and other structures.

This Monthly Roundup consists of quick snippets describing each of the currently published research articles in the exoALMA Focus Issue of the Astrophysical Journal Letters. Each snippet links to the corresponding research article, and the Focus Issue landing page is linked at the bottom of this post.

Introducing exoALMA

First up, exoALMA project PI Richard Teague (Massachusetts Institute of Technology) and collaborators introduced the survey, the disk sample, and the science goals. The team mapped the dust and gas distributions of 15 protoplanetary disks that were selected for their brightness, large size, lack of obscuration, and low inclination angles. The three key science goals were to 1) detect protoplanets hidden within the disks, 2) study the disks’ dynamical structures, especially as these structures relate to instabilities that can perturb the disks and determine their lifetimes, and 3) determine the disks’ density and temperature structure.

Interpreting interferometric data from ALMA requires special care, as Ryan Loomis (National Radio Astronomy Observatory) and coauthors show in their overview of the data calibration and imaging pipeline. The team described their methods of processing the data, including a recently developed alignment method that greatly reduces the number of artifacts that could be mistaken for planet-induced velocity perturbations.

Although extreme care was taken not to introduce spurious signals through the calibration process, it’s critical to perform additional tests to confirm that detected signals are real, rather than artifacts. To that end, Brianna Zawadzki (Wesleyan University) and coauthors presented exoALMA images processed with a procedure called regularized maximum likelihood. The regularized maximum likelihood–processed images showed the same non-Keplerian features as the images processed with the standard algorithm, suggesting that these features are real.

Analysis Methods and Toolkit Testing

Analyzing observations of protoplanetary disks is challenging, motivating Thomas Hilder (Monash University) and collaborators to take the first step toward addressing issues like beam smearing, the creation of probabilistic data products, and incorporating a realistic noise model. Using their newly developed methods, the team analyzed several disks in the exoALMA sample, finding velocity substructures at greater velocities than existing methods.

Andrés Izquierdo (University of Florida; Leiden University; European Southern Observatory) and collaborators described their methodology for investigating gas structure in the exoALMA sample. The team’s fitting method allowed them to separate the contribution of a disk’s front and back sides from the rest of its emission, leading to estimates of the orientation and vertical profile of each disk.

Jaehan Bae (University of Florida) and collaborators drew attention to the tools astronomers use to interpret observations of protoplanetary disks — namely, forward models. Bae’s team used five different hydrodynamics models to simulate a protoplanetary disk harboring an embedded giant planet. Then, they used two radiative transfer models to simulate carbon monoxide channel maps and calculate the temperature of the disk. Finally, they extracted the location of the synthetic planet. This investigation ultimately showed good agreements between the model outputs, showing that any combination of the models tested in this work is suitable.

Seeking Structure

A team headed by Pietro Curone (University of Milan; University of Chile) examined the rich ALMA dataset for signs of structure within the disks. The team modeled each disk with an axisymmetric model, then subtracted off the best-fitting model to reveal substructures and asymmetries in the disks. Several features were revealed, including shadows, offsets between inner and outer disks, spiral structures, and crescent-shaped asymmetries. Though one disk, PDS 66, was apparently without any internal structure, this investigation showed that structures are common in this sample of large, bright disks. Further work is needed, however, to explore whether these features are common in the disk population as a whole.

Maria Galloway-Sprietsma (University of Florida) and collaborators identified the disk surfaces that emit particular spectral lines. The team found that ¹²CO traced the upper atmosphere of the disks, while ¹³CO — an isotopologue of the more common molecule ¹²CO — and CS (carbon monosulfide) probed deeper regions. In addition, nearly all of the disks showed evidence of localized substructure, highlighting the need for theoretical work to explain the wide variety of disk structures and behaviors.

Evidence for Planets

Christophe Pinte (University Grenoble Alpes; Monash University) and collaborators analyzed substructures revealed by ¹²CO emission. These images revealed arcs, spiral arms, and kinks in 13 out of the 15 disks in the sample. Of these, six were consistent with wakes forming due to planets with masses between 1 and 5 Jupiter masses orbiting at 80–310 au.

Charles Gardner (Rice University; Los Alamos National Laboratory) and coauthors focused on LkCa 15, a disk that appears markedly different in dust and gas emission. The disk’s dust continuum emission shows a 40-au-wide region depleted of dust, while the gas emission, traced by CO, shows no depletion of gas in the same region. Though previous infrared observations have suggested that this dust-depleted region could host massive planets, Gardner’s team concluded that a chain of small planets or processes unrelated to planet formation likely excavated the region instead.

A team led by Jochen Stadler (Côte d’Azur University) searched for deviations from Keplerian rotational velocity — potential evidence for embedded protoplanets. The team discovered deviations up to 15% from the background velocity, with deviations appearing at both large and small radial scales. Rings and gaps visible in the dust emission tended to align with gas pressure maxima and minima, respectively. However, the team also found gas pressure structures in the outer disk that were beyond the dust emission and were not accompanied by rings or gaps.

Masses and Abundances

A team led by Cristiano Longarini (University of Cambridge; University of Milan) put the disks of the exoALMA sample on the scale. By modeling the rotation curves of ¹²CO and ¹³CO, the team constrained the masses of 10 disks and their central stars. Leon Trapman (University of Wisconsin-Madison) and collaborators also considered the problem of disk masses. The team used CO and N₂H⁺ emission to measure the gas masses of 11 disks in the exoALMA sample and compared the results to previous kinematic measurements. The two sets of measurements tend to agree within a factor of three.

Giovanni Rosotti (University of Milan) and collaborators introduced a new model that connects the emitting height of CO molecules to the gas surface density and temperature. Unlike existing models, the team’s new model can be applied to optically thick observations. Comparing the results of this new method with dynamical estimates relying on interstellar medium abundances of CO yields lower gas masses, suggesting that the CO abundance in the protoplanetary disks studied is depleted relative to the interstellar medium.

Turbulence, Traps, and Vortices

Protoplanetary disks are expected to experience turbulence, large-scale gas motions, and instabilities. Marcelo Barraza-Alfaro (Massachusetts Institute of Technology) and collaborators investigated whether a program like exoALMA could detect signs of these processes at work. The team used 3D numerical simulations to explore the observational signatures of the vertical shear instability, the magnetorotational instability, and the gravitational instability. They found that rings, arcs, and spirals can arise from instabilities. While spirals present in the disks in the exoALMA sample could feasibly be due to the magnetorotational instability or the gravitational instability, ring-like and arc-like features due to the vertical shear instability were not detected.

Tomohiro Yoshida (National Astronomical Observatory of Japan; The Graduate University for Advanced Studies) and collaborators reported on their detection of pressure-broadened emission-line wings in RX J1604.3−2130 A. This detection allowed the team to constrain the disk’s gas surface density — a critical property related to the mass available to form planets. They also clearly showed a dust ring coinciding with a gas pressure maximum, proving that gas pressure maxima can create dust traps. The gas-to-dust surface density ratio at the location of this dust trap suggests that the disk has already birthed protoplanets or the dust trapping efficiency is low.

Vortices are theorized to shepherd dust grains into crescent-shaped traps, providing an environment for dust grains to clump together and grow into planetesimals and eventually planets. Lisa Wölfer (Massachusetts Institute of Technology) and collaborators searched for kinematic signatures of dust-trapping vortices in CO line emission from four disks that exhibit crescent-shaped concentrations of dust. None of the four disks exhibited the clear signature of a vortex, and higher-resolution data or observations of emission lines that trace motions closer to the midplane of the disk may be necessary to probe this signal further.

The full list of articles in this Focus Issue can be found here.

Citation

“exoALMA. I. Science Goals, Project Design, and Data Products,” Richard Teague et al 2025 ApJL 984 L6. doi:10.3847/2041-8213/adc43b

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