Saturday, July 18, 2026

Faintest planet ever imaged from Earth found after more than 10 years of hide-and-seek

PR Image eso2609a
VLT image of the Beta Pictoris d exoplanet

PR Image eso2609b
The Beta Pictoris d exoplanet observed over the years

PR Image eso2609c
Map of the sky around Beta Pictoris

PR Image eso2609d
Around Beta Pictoris


Videos

New exoplanet had been hiding for more than 10 years | ESO News
PR Video eso2609a
New exoplanet had been hiding for more than 10 years | ESO News

Time-lapse of exoplanet Beta Pictoris d orbiting around its host star
PR Video eso2609b
Time-lapse of exoplanet Beta Pictoris d orbiting around its host star


A team of astronomers have discovered a third planet orbiting the star Beta Pictoris. The new planet, Beta Pictoris d, is 100 times fainter than Beta Pictoris b — the first planet discovered in the same system — and is among the lightest exoplanets ever to be imaged from the ground. After spotting the planet using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), the team found it had been hiding in archive observations spanning more than a decade.

“This was a serendipitous discovery,” says Ben Sutlieff, co-lead of the study published today in The Astrophysical Journal Letters and astronomer at the University of Edinburgh, United Kingdom. “We initially wanted to look more at a known planet in the system, Beta Pictoris b, to see how it changed over time,” he adds. However, when the team went to analyse their images of the system, they noticed something else, separated from Beta Pictoris b, that led them down an entirely new path.

“‘There’s something else there, did you see it?’” Markus Bonse, ESO astronomer in Germany and the other co-lead of the study, recalls saying when looking at the data. To confirm the nature of their detection, the team looked through the ESO archive, a catalogue of past observations made with ESO facilities. They found a new planet, Beta Pictoris d, in multiple images dating back as far as 11 years ago, including one where it was only just visible against the glare of its larger neighbour Beta Pictoris b. “Planet d, it seems, has been playing a game of hide-and-seek with us for over a decade and only now can we say ‘found you!’” says Jayne Birkby, co-author of the study and astronomer at the University of Oxford, United Kingdom.

The newly discovered planet, like the two others in the system, is a gas giant like Jupiter or Saturn. However, Beta Pictoris d has a much wider orbit than the planets Beta Pictoris b and Beta Pictoris c. Moreover, while the first two planets are each around ten times the mass of Jupiter, the new planet is only 2.4 times more massive than Jupiter, making it one of the lightest ever imaged from the ground. The planet is also relatively cold and, hence, extremely faint relative to its host star.

Direct imaging, where the light from an object is captured as in a photograph, only works for planets bright enough to show up next to their much brighter host stars. Taking a direct image of a planet as faint as Beta Pictoris d, therefore, represents a significant achievement. “The new planet is 100 times fainter than Beta Pictoris b, the famous planet in the same system, making it the faintest exoplanet ever imaged directly from Earth,” explains Bonse [1].

This first clear detection of Beta Pictoris d, which is 63 light-years away from us, was made with the ERIS instrument on the VLT by Sutlieff, Bonse and their team. An independent team led by Aidan Gibbs at the University of California, US, also discovered the same planet using the James Webb Space Telescope (JWST), a facility of the US, European and Canadian space agencies. Their results are also published today in The Astrophysical Journal Letters.

To confirm a planet’s discovery from a detection, astronomers usually have to make follow-up observations. However, this system had been extensively studied, with several images stored in the ESO and JWST science archives. “To our joy, out it popped in previous SPHERE observations,” says Birkby, referring to another VLT instrument previously used to observe the Beta Pictoris system. The planet was also spotted in archival observations from NIRCam, a JWST instrument. Now that the team knew where to look for the potential new planet, “it turns out it was hiding in the data all along!” says Birkby. Co-author Valentin Christiaens, researcher at CEA Paris-Saclay, France, adds: “The detections in the archival SPHERE data are not only very exciting on their own, but also because they suggest a number of treasures are still hidden in the archives of VLT instruments!”

Beta Pictoris is now the second system, after HR 8799, where more than two planets have been directly imaged. “Systems with multiple directly imaged exoplanets are the ‘holy grails’ of discoveries, because they can teach us a lot about what different exoplanets are like in the same formation environment,” says Sutlieff [2]. Beta Pictoris d also clears up a mystery in its planetary system, as it has exactly the right mass and position to explain the particular shape of the surrounding debris disc, made of the leftovers of planet formation.

The discovery of Beta Pictoris d in this way encourages further direct imaging of planetary systems where faint planets may have been hiding in plain sight, including with ESO’s upcoming Extremely Large Telescope (ELT). “Planets seem to have friends,” says Beth Biller, also a co-author of the paper and astronomer at the University of Edinburgh, “many of the famous directly imaged exoplanet systems seem to have multiple giant planets in the same system, and likely there are even more lower mass planets hiding in these systems that might be revealed with instruments on the ELT.”


Source: ESO/News


Notes
[1] Beta Pictoris d is the faintest exoplanet ever imaged from Earth when corrected for the distance to the system — faintest in absolute magnitude (owing to its size and temperature only) not in apparent magnitude (where distance also contributes to faintness).

[2] Beta Pic is part of a group of stars all with the same age, and some of them have planets too. Beta Pic d seems to be almost a twin of one of these planets, 51 Eri b, meaning astronomers can use them both to anchor their models of how planets evolve and grow over time.


More information
This research was presented in a paper to appear in The Astrophysical Journal Letters (https://doi.org/10.3847/2041-8213/ae80a0).

This paper, co-led by B. J. Sutlieff and M. J. Bonse, involves over 90 authors from around the world, including Belgium, France, Germany, Ireland, Italy, the Netherlands, Switzerland, the United Kingdom and Chile.

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration for astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, Czechia, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as survey telescopes such as VISTA. Also at Paranal, ESO will host and operate the south array of the Cherenkov Telescope Array Observatory, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates ALMA on Chajnantor, a facility that observes the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chileanpartners and society.


Links

Contacts:

Ben Sutlieff
Institute for Astronomy, University of Edinburgh
Edinburgh, United Kingdom
Email: ben.sutlieff@roe.ac.uk

Markus Bonse
European Southern Observatory (ESO)
Garching bei München, Germany
Email: Markus.Bonse@eso.org

Jayne Birkby
Department of Physics, University of Oxford
Oxford, United Kingdom
Email: jayne.birkby@physics.ox.ac.uk

Valentin Christiaens
CEA Paris-Saclay, Université Paris-Saclay, Université Paris Cité, CEA, CNRS
Paris, France
Tel: +33169083661
Email: valentin.christiaens@cea.fr

Beth Biller
Institute for Astronomy, University of Edinburgh
Edinburgh, United Kingdom
Tel: +44 (0)131 668 8349
Email: bbiller@ed.ac.uk

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Tel: +49 89 3200 6670
Cell: +49 151 241 664 00
Email: press@eso.org

Press and Public Relations
University of Edinburgh
Edinburgh, United Kingdom
Tel: +44(0)7979 446 209
Email: press.office@ed.ac.uk

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Light-bending by extreme gravity

An artist's impression of an accretion disk of material swirling into a black hole, with a hot corona illustrated by a purple haze. The apparent warping of the disk is due to the extreme gravity of the black hole bending the light paths around it. Image credit: NASA/Caltech-IPAC/Robert Hurt - Download Image

During the past week, NuSTAR performed a 5-day long observation of the nearby active galaxy MCG-06-30-15 in coordination with JAXA/NASA/ESA’s XRISM observatory and NASA’s IXPE observatory. For nearly three decades, this source has been a premier X-ray target for studying the extreme environment around a supermassive black hole. One long-standing puzzle is the dramatic variability of direct X-ray emission from the hot corona—the compact cloud of energetic particles near the central engine—while reflected X-rays off the accretion disk vary much less. One possible explanation is relativistic light-bending by the supermassive black hole: changes in the geometry of the corona, particularly its height above the black hole, will strongly affect X-ray photon paths. MCG-06-30-15 naturally cycles through bright and faint states on timescales of only a few hours, so a 5-day observation should track this evolution in real time. NuSTAR’s unique sensitivity to high-energy X-rays allows it to track both the primary coronal emission and reflected X-rays across flux states, while XRISM's unprecedented spectral resolution simultaneously measures changes in iron emission line from the accretion disk. Together, these observations will provide one of the most direct tests yet of whether relativistic light bending drives the observed X-ray variability, while revealing how the geometry of the corona evolves as the source changes brightness. Simultaneous X-ray polarization measurements from NASA’s IXPE observatory will also provide an independent probe of the coronal geometry, offering a powerful complementary test of this picture.

Author: Indrani Pal (Postdoctoral Fellow, Clemson University)


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Friday, July 17, 2026

Astronomers Detect Magnetic Fingerprint of a Cosmic Explosion for the First Time

This illustration depicts Faraday rotation in the afterglow of a gamma-ray burst. A powerful jet (upper left) sends polarized radio waves outward through the thin wall of a surrounding bubble of magnetized gas called an HII region. As the light passes through this material, its polarization angle is twisted by the magnetic field. Because the effect is stronger at longer wavelengths, the red and blue waves, which represent different radio wavelengths, exit the bubble oscillating in different directions. By measuring this difference, astronomers were able to map the magnetic environment surrounding GRB 260310A for the first time. Credit: NSF/AUI/NSF NRAO/M.Weiss. Hi-Res File


NSF VLA radio telescope reveals polarized light and a powerful magnetic environment in a gamma-ray burst afterglow

Astronomers have made a series of landmark observations of one of the Universe’s most violent events. Using the U.S. National Science Foundation Very Large Array (NSF VLA) radio telescope, which is operated by the U. S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO), the team detected polarized light from a gamma-ray burst (GRB) afterglow for the first time at radio wavelengths. It also marks the first time scientists have detected Faraday rotation in a GRB, a phenomenon in which magnetic fields cause the polarization of light to twist as it travels through space, revealing how the magnetic environment of these explosions interacts with the light they produce. The findings, led by researchers at the University of Arizona and the University of Utah, offer a new window into the extreme physics driving these titanic explosions.

What Are Gamma-Ray Bursts?

Gamma-ray bursts are the most powerful explosions in the Universe, releasing in a matter of seconds as much energy as the Sun will emit over its entire lifetime. They are thought to launch narrow jets of particles accelerating to nearly the speed of light, and those jets produce a radio “afterglow” that can linger for months. Despite decades of study, the magnetic fields that are believed to accompany these jets and their local environments have remained stubbornly difficult to measure, until now.

GRB 260310A Reveals Polarized Radio Waves

The burst in question, designated GRB 260310A, was relatively nearby Earth, in cosmic standards, making its radio afterglow one of the brightest seen in decades. That brightness gave astronomers an extraordinary opportunity. By pointing the NSF VLA at the fading explosion, the team found that the radio waves were polarized, meaning the light waves were oscillating in a preferred direction, much like sunlight reflecting off the surface of water, which polarized sunglasses are designed to filter out.

Faraday Rotation in a Gamma-ray Burst

This alone would have been an exciting first for the NSF VLA. But the team made an even more extraordinary discovery: the polarization signal changed across different wavelengths, a phenomenon known as Faraday rotation. Never before detected in a gamma-ray burst, this effect acts like a magnetic fingerprint, encoding information about the strength and structure of the fields the light passed through. Just as a prism bends different colors of visible light by different amounts, a magnetized plasma can rotate the polarization angle of radio waves. The faster that rotation changed with wavelength, the stronger the magnetic field the light passed through.

“GRBs are the most powerful explosions in the Universe, and magnetic fields are thought to play a central role in powering them, but probing those fields has been extraordinarily difficult,” said Tanmoy Laskar, assistant professor at the University of Utah. “By detecting polarized radio emission, we can now directly measure the magnetic environment of one of the Universe’s most violent events. Our new GRB observations allow us to use the Universe as our laboratory to test our understanding of how physics operates in such extreme conditions.”

The NSF VLA data revealed a magnetic field along the light’s path that was thousands of times stronger than what could be explained by our own galaxy or the space between galaxies. Instead, it points to an exceptionally dense, magnetized cloud of gas surrounding the star that exploded to produce GRB 260310A.

Clues for GRB Origins

That cloud is what astronomers call an HII region, a bubble of ionized hydrogen gas shaped by powerful ultraviolet radiation and stellar winds from a massive young star. The fact that GRB 260310A appears to have exploded inside such a region is consistent with GRBs arising from the deaths of the most massive stars, and may help scientists understand precisely what kinds of stars and environments are capable of producing these extreme events.

“Previous searches for polarization in GRBs used facilities like the Atacama Large Millimeter/submillimeter Array (ALMA) telescope that measure shorter wavelengths and had to happen early, before the afterglow light faded,” said Collin Christy, a graduate student at the University of Arizona and lead author of the study. “Now, with the NSF VLA, we’ve pushed into the centimeter bands and made the first ever measurement of Faraday rotation in a GRB. Each new observation reveals another layer of the magnetic story these explosions are telling us.”

Why it Matters “Future monitoring of GRB afterglows with the NSF VLA and other radio telescopes will allow scientists to watch magnetic field structures evolve in real time,” said Assistant Professor Dr. Kate Denham Alexander, Christy’s PhD advisor. “This is a capability that could transform our understanding of how relativistic jets form, how they are powered, and how magnetic energy is released in the most extreme environments the Universe has to offer.”



About NRAO
The National Radio Astronomy Observatory (NRAO) is a facility of the U.S. National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

About ALMA
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 the construction, commissioning and operation of ALMA.

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VLA Sky Survey Sets New Standard for High-Resolution, Wide-Area Radio Astronomy

Credit: NSF/AUI/NSF NRAO
Hi-Res File

VLASS2.1.se.T28t01.J001924+723000 (0:13:00.8, 72:31:18.7 - Planetary Nebula/Tycho Brahe SN Remnant) (Left) & VLASS2.1.se.T27t08.J122846+673000 (12:33:14.1, 67:07:43.8 - Radio Galaxy) (Right). Credit: NSF/AUI/NSF NRAO/VLASS - Hi-Res File


The U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO) has completed observations for the Very Large Array Sky Survey (VLASS), the most detailed radio survey of the sky ever conducted, providing an unprecedented view of the dynamic radio universe.

Scope and Scale of VLASS

Conducted with the U.S. National Science Foundation Very Large Array (NSF VLA), VLASS spans nearly a decade of observations, from September 2017 through February 2026, and represents one of the most ambitious radio surveys ever undertaken. Covering approximately 34,000 square degrees, essentially the entire sky visible to the VLA down to -40 degrees declination, the survey delivers a powerful new resource for astronomers worldwide. The survey produced approximately 0.5 petabytes of raw data, and the total volume of processed data products is expected to reach about 2 petabytes, making it the largest survey the VLA has undertaken in terms of data volume.

“With VLASS, we now have a radio map of the sky that matches the resolution of modern optical and infrared surveys,” said Amy Kimball, VLASS Head of Operations. “This opens the door to truly multiwavelength discoveries at a level of detail that was not previously possible.”

VLASS achieves an angular resolution of about 2.5 arcseconds, making it the highest-resolution full-sky radio survey to date. Observations were carried out across the 2–4 GHz frequency range, enabling astronomers to measure in-band spectral indices, which are key to understanding the physical processes powering radio emission from cosmic sources.

Observing Strategy and Coverage

Over the course of roughly 6,500 observing hours, the NSF VLA repeatedly scanned the sky using an innovative “on-the-fly mosaicking” technique. In this mode, antennas continuously sweep across the sky in a raster pattern while collecting data, maximizing efficiency and uniform coverage. The survey observed the sky three and a half times in total, with half the sky imaged four times and the other half three times, enabling both deep imaging and the detection of variable and transient sources.

VLASS was conducted in full polarization, allowing astronomers to probe cosmic magnetic fields through measurements such as Faraday rotation. These data provide new insights into the structure and evolution of magnetism across the universe. The survey is a cornerstone of NSF NRAO’s Science Ready Data Products initiative, which provides fully calibrated data and high-quality images directly to the scientific community and the public. By lowering technical barriers, VLASS makes cutting-edge radio astronomy accessible to both experts and non-specialists.

VLASS is designed to address four major science themes:
– Hidden Explosions and Transient Events, including supernovae, gamma-ray bursts, and other short-lived phenomena.
– Faraday Tomography of the Magnetic Sky, using polarization data to map magnetic fields across cosmic environments.
– Imaging Galaxies through Time and Space, tracing the evolution of galaxies and active galactic nuclei.
– The New Milky Way, revealing previously unseen structures and sources within our own galaxy.

These themes are described in detail in the survey’s foundational paper (Lacy et al. 2020, PASP, 132, 035001), which outlines the scientific goals and design of VLASS.

A Legacy Dataset for the Future

By combining high resolution, wide sky coverage, spectral information, and time-domain sensitivity, VLASS establishes a new benchmark for radio surveys and provides a legacy dataset that will support discovery for years to come. Processing and imaging of the full dataset will continue over the next several years as these science-ready products are completed and released.

“VLASS is not just a survey, it is a long-term investment in the future of astrophysics,” said Mark Lacy, VLASS Project Director. “Its combination of depth, coverage, and accessibility ensures that it will remain a foundational resource for the community.”

Additional information and access to VLASS data products are available through NRAO here.



About NRAO
The National Radio Astronomy Observatory is a major facility of the U.S. National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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Thursday, July 16, 2026

NASA’s Roman Telescope Will Spot Distant Black Holes That Shred Stars

This artist’s concept portrays a Sun-like star being shredded by a supermassive black hole — a phenomenon known as a tidal disruption event. During these events, the region around a black hole can brighten and become visible across great distances. NASA’s Nancy Grace Roman Space Telescope will be able to spot and study tidal disruption events that occurred early in the universe’s history. By characterizing an earlier population of supermassive black holes, astronomers can learn about their origins. Credit: NASA, Ralf Crawford (STScI)


This visualization shows the average number of tidal disruption events NASA’s Nancy Grace Roman Space Telescope is predicted to detect in a year, based on simulations. Roman is expected to record about 100 such events in a year. Video: NASA, STScI. Visualization: Christian Nieves (STScI). Sound: Christian Nieves (STScI). Designer: Dani Player (STScI). Animation: Greg Bacon (STScI). Link Video 


Black holes are best studied by looking for the light emitted from their accretion disk — the matter that swirls around them before being consumed. Lighter supermassive black holes are challenging to observe because they tend to be less luminous due to less accretion. But occasionally, they shred and consume an entire star, brightening to outshine their entire host galaxy — known as a tidal disruption event (TDE). By characterizing that population of early supermassive black holes and how they evolve and grow for billions of years, Roman will provide clues to the ultimate origin of these behemoths.

“The Roman Space Telescope is going to be transformative for transient science,” said lead author Mitchell Karmen of the Johns Hopkins University, a graduate student and National Science Foundation Graduate Research Fellow. “Thanks to Roman’s high sensitivity, we can find multiple tidal disruption events out to greater distances and earlier cosmic times than ever before.”

A paper about this research published Tuesday in The Astrophysical Journal.

Shredding Stars

Roman’s High-Latitude Time-Doman Survey, one of three core community surveys, is particularly well suited to find and study TDEs in the early universe. This survey will cover about 18 square degrees on the sky, an area equivalent to 90 full moons, at a regular cadence. By revisiting the same regions repeatedly, astronomers can find large numbers of transient events like TDEs.

Tidal disruption events are phenomena unique to lighter supermassive black holes. Heftier black holes weighing more than 1 billion Suns will swallow incoming stars whole. But lighter black holes of about 100,000 to 100 million Suns can shred a star before consuming it, creating a beacon that brightens over a couple of weeks before gradually fading away.

The rate of TDEs fluctuates over cosmic time. Previous work predicted that the rate of TDEs would decrease with increasing distance because most young black holes were too light to generate a TDE. However, this new research takes into account numerous factors that evolve over time, like the frequency of galaxy (and hence black hole) mergers as well as the number of stars within the core of each galaxy and how closely packed they are.

Karmen and his colleagues modeled these and other effects to predict how many tidal disruption events Roman could observe, as well as other observatories like the ground-based National Science Foundation-Department of Energy Vera C. Rubin Observatory and NASA’s James Webb Space Telescope. The team forecasts that astronomers will see the rate of TDEs increase as Roman probes greater distances and earlier times until “cosmic noon,” about 11 to 12 billion years ago when star formation peaked throughout the universe, before decreasing again.

Complementary Observations

Roman will observe near-infrared wavelengths of light. Light from distant TDEs becomes stretched to longer wavelengths by the expansion of the universe, a phenomenon known as cosmological redshift. As a result, Roman is inherently optimized to detect TDEs whose light traveled anywhere from 8 billion to 11 billion years to reach us.

The Rubin Observatory also will scan large swaths of the sky and pick up many new TDEs. However, it will observe visible light, which limits it to closer TDEs than Roman.

The research by Karmen’s team finds that Rubin will detect thousands to tens of thousands of TDEs per year. While Roman is expected to find up to 100 TDEs per year, those black holes will be much more distant, within the realm of cosmic history that is most important for distinguishing among black hole origin scenarios.

“Just by counting the number of TDEs as a function of redshift, you can put meaningful constraints on the population of million-solar-mass black holes,” said co-author Suvi Gezari, an associate professor of astronomy at the University of Maryland. “Roman will be transformative in that it can probe tidal disruption events out to greater distances, so you can look at how the rate of TDEs evolves over time.”

Origins of supermassive black holes

Astronomers have observed truly gargantuan black holes very early in the history of the universe — so early that theories struggle to explain how they could have become so large, so quickly. They must have started smaller and grown over time, but how much smaller?

One theory, known as “light seeds,” begins with black holes that are created from the deaths of massive stars. Such black holes might weigh up to a few hundred times our Sun. These black holes then would merge over time, as well as consume surrounding gas at an astonishing rate. In this scenario, every young galaxy would be expected to have a massive black hole at its center.

A second theory, known as “heavy seeds,” suggests that a black hole could be born with a much higher mass, up to a million times our Sun, through a process such as the direct collapse of a gas cloud. This process should be less common, though, which would result in supermassive black holes being much rarer in early galaxies.

“Tidal disruption events help us probe the population of light supermassive black holes, which can help us discriminate between these models,” Karmen said.

Ultimately, Roman’s tally of tidal disruption events will help researchers trace global effects that impact the black hole population over time.

Once Roman and Rubin begin regular science operations, the team looks forward to comparing their forecasts to the actual detections those observatories make.

“Just like Webb has transformed our understanding of distant, high-redshift galaxies, Roman is poised to transform our understanding of high-redshift transients,” Gezari said.

The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc. in Boulder, Colorado; L3Harris Technologies in Melbourne, Florida; and Teledyne Scientific & Imaging in Thousand Oaks, California.



By Christine Pulliam
Space Telescope Science Institute, Baltimore, Md.

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-1940

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NASA’s Hubble Discovers First of Star Cluster’s Missing Black Holes


Omega Centauri Context Image
Astronomers found ’s first stellar-mass black hole, which has a visible star companion that is shown in greater detail. They used 20-plus years of data from NASA’s Hubble Space Telescope and recent data from NASA’s James Webb Space Telescope to make the discovery. Credit Image: ESA, NASA, Maximilian Häberle (MPIA), Joseph DePasquale (STScI)

The precise data collected by NASA’s Hubble and James Webb space telescopes enabled a team of astronomers to chart the visible star’s orbital path over a 20 year-plus period. Credit Animation: NASA, ESA, Matthew Whitaker (U of Utah), Joseph Olmsted (STScI)


The massive globular star cluster Omega Centauri has puzzled astronomers for decades. It should be filled with black holes left behind by exploding stars, yet evidence for them is scarce. Now, astronomers using archival data from NASA’s Hubble Space Telescope and supportive observations from NASA’s James Webb Space Telescope have finally located their first stellar-mass black hole in this cluster. Discovering the first of this missing black hole population will help refine current theories on black hole formation within environments such as Omega Centauri. The team’s findings published Monday in The Astrophysical Journal Letters.

Omega Centauri is composed of 10 million gravitationally bound stars. Though the astronomical community previously found evidence with Hubble that an intermediate-mass black hole lurks at its center, models suggest this star cluster should also contain about 10,000 smaller, stellar-mass black holes. This notable population of black holes evaded detection in previous observational studies, which used the radial velocity method or looked for radio and X-ray emission from material falling onto black holes.

This new discovery features a different approach, known as astrometry, to measure very small movements of stars over time. By sifting through more than 20 years of Hubble archival data and pulling in recent Webb data to further refine their astrometric measurements, the team located a star orbiting an invisible object so hefty that it has to be a black hole. Dubbed oMEGACat BH-2, it is the first stellar-mass black hole detected in Omega Centauri, and it has some surprising qualities. oMEGACat BH-2 has a lower-than-expected mass and, with its visible star companion, the black hole-star duo has the longest orbital period of any black hole binary system known to date.

“With Hubble and Webb data, we were able to see the motion of the visible main sequence star that is part of this binary, which is about 18,000 light-years away in the dense environment of Omega Centauri,” said Matthew Whitaker of the University of Utah, Salt Lake City, lead author of the paper. “The precision of these measurements is incredible, down to a fraction of a pixel on Hubble and Webb’s detectors. It would not have been possible to find this black hole without these two space telescopes.”

Long time coming

Based on the precise data from Hubble and Webb, the team could chart he star’s path over 20-plus years, during its closest approach to its black hole companion when it moved the fastest across the sky. From the extensive data, the team determined that the visible star orbits oMEGACat BH-2 once every 94 years, making it the longest-period black hole binary ever known.

Its long orbital period also gives a clue to the origin of this binary system. It was probably dynamically formed, meaning the star and its black hole companion did not start out together but rather found each other in this cluster. The researchers calculated that a system like oMEGACat BH-2 will survive for less than a billion years before it is torn apart by encounters with nearby stars, a much shorter span than the age of the cluster (approximately 12 billion years old).

“It's important to understand black hole populations in globular clusters because there's uncertainty about their physics and formation,” said Seth. “More specifically, understanding the process of forming black holes and then dynamically forming binaries is vital, because it affects our ability to interpret and understand gravitational wave events. Environments like Omega Centauri are the primary places where we think binaries are merging and creating these waves.”

The team’s discovery of stellar-mass black hole oMEGACat BH-2 with the Hubble-Webb dataset is just the start of finding these evasive black hole populations in globular star clusters.

“With Hubble and Webb, we can continue to look at Omega Centauri and expand our search for similar systems within other clusters,” said Whitaker. “We’re also very excited for the launch of NASA’s Nancy Grace Roman Space Telescope because it will image the crowded galactic bulge, including the galactic center, very regularly with Hubble-like resolution and with a much wider field of view. We’re hoping we’ll be able to find black hole binary systems like this one because of the regular cadence of Roman’s observations.”

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.



Details

Last Updated: Jul 13, 2026
Editor: Andrea Gianopoulos
Location: NASA Goddard Space Flight Center

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Wednesday, July 15, 2026

First Completed Rocky Worlds Program Observations Open New Era in Exoplanet Studies

This artist’s concept shows an M dwarf star, also called a red dwarf star, and a planet. Most rocky planets in the Milky Way galaxy orbit red dwarf stars, which are smaller and cooler than the Sun, but can be much more active, bombarding nearby planets with high-energy X-rays and ultraviolet light.

The Rocky Worlds Director’s Discretionary program, a combined effort by NASA’s Webb and Hubble Space Telescopes, is underway to explore whether rocky planets can maintain atmospheres in this environment.

The team recently completed observations of the first target, Earth-sized rocky planet GJ 3929 b and its star GJ 3929. Credits Illustration: STScI, Ralf Crawford (STScI)


Scientists leading the astronomy community’s most ambitious effort to study rocky planets outside of our solar system have reached a major milestone.

The team has completed the coordinated observations of the first target, an Earth-sized rocky planet GJ 3929 b and GJ 3929, the red dwarf star it orbits, using NASA’s James Webb and Hubble Space Telescopes.

While the planet itself is scientifically compelling, researchers say the importance of this milestone extends far beyond a single target.

“This was our proving ground,” said Néstor Espinoza, Rocky Worlds Director’s Discretionary Time (DDT) program lead and mission scientist for exoplanet science at the Space Telescope Science Institute (STScI) in Baltimore. “Finishing these first observations shows that the program works technically, scientifically, and collaboratively.”

The Rocky Worlds DDT program was designed to create a foundational, community-driven dataset for studying rocky exoplanets with Webb and Hubble . While Webb measures mid-infrared light coming from each planet to determine whether it has an atmosphere, Hubble is analyzing ultraviolet light from each host star to assess the planet’s radiation environment.

STScI leads the effort to design the observing strategy, manage the program’s technical implementation, and build the collaborative framework connecting scientists across the broader exoplanet community.

“This team’s efforts reflect the best of the institute’s unique ability to bring together expertise in science operations, engineering, scheduling, software development, and large-scale program management to execute some of astronomy’s most technically challenging observations and answer some of the universe’s biggest questions,” said STScI Director Jennifer Lotz.

The GJ 3929 system became the program’s first completed target after emerging early as one of the strongest candidates for initial observations. Scientists selected the star and its planet through a multi-stage community process involving Science Advisory Council discussions, mini-surveys, and feedback from researchers across the exoplanet community.

The team emphasizes that the target was not chosen because it was expected to produce the most dramatic discovery. Instead, it represents an important balance: scientifically valuable, observationally feasible, and ideal for helping the team learn how to execute a complex program involving complementary observations, some of which are captured simultaneously, from multiple flagship observatories.

The observations required researchers to precisely predict when the planet would pass behind its star, an event known as a secondary eclipse. Even for a comparatively favorable target like GJ 3929 b, uncertainties in the planet’s orbit created significant technical challenges.

Completing the observations demonstrated that the team could overcome those challenges and establish a framework for future targets, many of which are expected to be even more difficult.

“This is exactly why the Rocky Worlds program exists,” added Hannah Diamond-Lowe, deputy lead of the program and assistant astronomer at STScI. “These are high-risk, high-reward observations. Completing this first target shows we know how to do it.”

The milestone also highlights the remarkably collaborative nature of the program. Scientists from around the world shared unpublished supporting observations, including radial velocity measurements used to refine the planet’s orbit and improve scheduling predictions, to help develop and refine the observation plans.

At the same time, the Rocky Worlds team is building new systems intended to encourage open collaboration while reducing duplicated effort across the field and grow the scope, impact and scientific return of the program, including the recently launched Rocky Worlds DDT Data Challenge. The new Community Involvement Initiative also provides an open forum for researchers and research to facilitate share information on analysis techniques, complementary and follow-up observations, project ideas, and plans for publications.

The program’s leaders say this collaborative structure was part of the vision from the beginning.

“We wanted to create something that belonged to the community,” Espinoza said. “The goal is not only to produce groundbreaking science, but also to build a framework where many researchers can contribute, collaborate, and learn together.”

The data, which are immediately available as soon as they’re downloaded from the telescope, have swiftly sparked scientific interest in the community. Some researchers have already started analyzing the data and publishing their conclusions.

For the Rocky Worlds team, that response reinforces the significance of the milestone.

The Space Telescope Science Institute is expanding the frontiers of space astronomy by hosting the science operations center of the Hubble Space Telescope, the science and mission operations centers for the James Webb Space Telescope, and the science operations center for the Nancy Grace Roman Space Telescope. STScI also houses the Barbara A. Mikulski Archive for Space Telescopes (MAST) which is a NASA-funded project to support and provide to the astronomical community a variety of astronomical data archives, and is the data repository for the Hubble, Webb, Roman, Kepler, K2, TESS missions and more. STScI is operated by the Association of Universities for Research in Astronomy in Washington, D.C.



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Tuesday, July 14, 2026

Probing the host galaxy of one of the most distant quasars

Artist's impression of the early quasar with its starforming host galaxy.
© T. Müller, HdA/MPIA


To the point:
  • Super-effective distant quasar hunter: the ESA space telescope Euclid has found a treasure trove of early quasars, including two at record-breaking distances, and is poised to find many more.

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  • First look at ordinary early quasars: This is the first time astronomers can examine very early quasars that are ordinary, instead of seeing only the very brightest quasars.

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  • A massive, star-forming host galaxy: Follow-up on the galaxy hosting one of those ordinary quasars reveals a massive galaxy forming many stars – a new piece for the puzzle of galaxy formation.


ESA’s space telescope Euclid has opened up a new chapter in the study of early galaxies. New research by Silvia Belladitta (Max Planck Institute for Astronomy, MPIA) and colleagues has followed up on one of the Euclid discoveries to uncover key properties of the host galaxy of one of the earliest supermassive black holes known in the universe.

Bright objects with a dark center

Active galactic nuclei known as quasars are responsible for some of the brightest celestial objects we see in the sky. The “engine” behind that enormous luminosity is matter falling onto a central supermassive black hole – a black hole with masses of millions, billions or an even greater number of solar masses. Such supermassive black holes are found in all but the smallest galaxies. Energy from the 'central engine' influences star formation in a galaxy (in particular the most massive galaxies): by either heating or compressing the gas that is the raw material for new stars, limiting star formation in the first case, enhancing it in the second.

How the first galaxies and their central black holes emerged is a highly active area of research. Finding the earliest quasars and examining their properties and the properties of their host galaxies is an important piece of the puzzle. But targeting the earliest quasars is challenging. Objects that we see as they were in the early universe are necessarily very far away. When light reaching our telescopes today shows us a quasar as it was 13.4 billion years ago, that is because the light needed 13.4 billion years to travel from its source to our telescopes.

Searching for “ordinary” quasars

At such great distances, even intrinsically bright objects like quasars appear rather dim. Easiest to observe are particularly bright specimens – but those, being exceptionally bright, are unlikely to be representative of their more normal siblings. When it comes to the population of quasars, we had so far seen only the tip of the iceberg. This is changing: Euclid’s combination of sensitivity and the ability to scan large areas of the sky at once makes it an ideal search machine for quasars in the early universe. Follow-up observations with ground-based telescopes confirm Euclid’s remarkable quasar-finding power.

Eduardo Bañados, group leader at MPIA and co-lead of the Euclid Quasar Work Package from 2022 to 2025, says: “Seeing Euclid deliver on its potential is immensely satisfying. But more than that, it marks a genuine shift: For the first time, we can study the typical early-universe quasar, not just exceptional outliers. We now have a real window onto how the bulk of the first black holes grew — and how they shaped the galaxies around them."

After only 1.5 years of data-taking, Euclid has more than doubled the number of known early quasars, from nine to 21 (“redshift z>7 quasars”, seen as they were less than 800 million years after the Big Bang). In fact, within a few months, Euclid broke the quasar redshift record not once, but twice!

Probing an extremely distant host galaxy

One refreshingly ordinary early quasar is the one that Belladitta and her team examined more closely. The quasar has the designation EUCL J125308.55+705432.3 (in the usual astronomy fashion, less a name than a detailed sky position). Light we receive today from this quasar was emitted 13 billion years ago, a mere 800 million years after the Big Bang (“z=7.7”). Its UV light amounts to only about 15% the brightness of previous redshift record-holding quasars.

For their follow-up, the astronomers used the NOEMA (NOrthern Extended Millimeter Array) observatory on the Plateau de Bure in the French Alps. NOEMA’s twelve 15-m-antennas act in concert like a single, much larger telescope. The astronomers observed submillimeter light at two carefully chosen wavelengths, each of which traces a different property of the quasar’s host galaxy.

Star formation and dust content

The first type of light is what astronomers call the [CII] line. This kind of light is produced in clouds of molecular gas where new stars are being born. The brightness of this line therefore indicates a galaxy’s star formation rate. The light also allows for a mass estimate: If you have ever heard the way that an emergency vehicle’s siren sound changes as the vehicle passes by, you know how motion influences the wavelength of waves. Applying the same principle in reverse, the way that the [CII] line is shaped allows astronomers to reconstruct the motion of gas in the quasar’s host galaxy, which in turn yields an estimate of its total mass.

The second type of light is thermal radiation from the cold dust in a galaxy. The intensity of this light reveals how much dust is present. The amount of dust is typically associated with the amount of molecular hydrogen, the raw material for star formation – of which this quasar appears to have a lot!

Reconstructing the galaxy’s star-formation rate

Taken together, Belladitta and her colleagues were able to reconstruct key properties of the galaxy that is hosting the quasar. The galaxy is forming stars at a rate of more than 250 solar masses per year – an impressive amount compared to the one solar mass per year of our own Milky Way, but not unexpected given previous finds for less distant quasars. The galaxy’s mass is estimated at around ten billion solar masses, a factor ten less than our own Milky Way. This is consistent with early galaxies that still have a lot of growth ahead of them.

"We found a galaxy that has all the ingredients to build a giant system: it is as massive as the hosts of the brightest early quasars and contains a huge reservoir of molecular gas to fuel intense star formation,” says Silvia Belladitta, a postdoctoral researcher at MPIA. Belladitta, who is the lead author of the study and the new co-leader of the Euclid Quasar Work Package, adds: “This raises an intriguing possibility. UV-faint quasars like EUCL J125308.55+705432.3 may be in a different evolutionary phase than their brighter cousins. Either the black hole is growing more slowly than in the brightest quasars, or else much of its activity is hidden behind thick clouds of dust. Distinguishing between these possibilities will be an exciting challenge for future observations.”

Future plans

For the big picture of galaxy evolution, these are incremental results. But they are pioneering achievements nonetheless, and they point the way forward: with the full 6-year Euclid survey expected to uncover hundreds of additional early quasars of this kind, and with follow-up observations like those of Belladitta and her colleagues providing an ever-larger set of information about star formation rates and galaxy masses, astronomy is steadily building a picture of the earliest galaxies and supermassive black holes in the universe. This will bring the story of the origin of galaxies, and of ourselves, into ever sharper focus.

Background information

The results described here have been published as Belladitta et al. “Euclid: A UV-faint quasar in a highly luminous star-forming host galaxy at z≈7.7” in the journal Astronomy & Astrophysics, doi: 10.1051/0004-6361/202659319. The Euclid quasar search results have been published as D. Yang et al., “Euclid: Discovery of 31 new quasars at 6.6 < z < 7.8” in the journal Astronomy & Astrophysics, doi: 10.1051/0004-6361/202658883.

The MPIA scientists involved are Silvia Belladitta, Eduardo Banados, Fabian Walter, Knud Jahnke, Sarah Bosman, Julien Wolf, and Mischa Schirmer, in collaboration with Roberto Decarli (INAF Observatory, Bologna), Daming Yang (Leiden Observatory), Francesco Guarneri (University of Hamburg) and the rest of the EuclidCollaboration.

Euclid is ESA's mission to characterize Dark Energy and Dark Matter across cosmic time. Launched in 2023, Euclid will survey a third of the sky, recording images for two billion galaxies and precise distances of 50 million galaxies. Euclid's first major data release DR1 will provide data to the world for almost 2000 square degrees in November 2026. The Max-Planck-Institute for Astronomy (MPIA) is a founding member of the Euclid Consortium, a group of now more than 150 institutions across Europe, Canada, Japan, and the USA. During its construction MPIA has contributed hardware for the near-infrared instrument onboard Euclid. Now MPIA scientists are involved in its operation in orbit and are leading Euclid's overall calibration work.



Contacts:

Dr. Markus Pössel
Head of press relations and outreach
Tel: +49 6221 528-261
Email: pr@mpia.de
Max Planck Institute for Astronomy, Heidelberg

Dr. Silvia Belladitta
Tel: +49 6221 528-102
Email: belladitta@mpia.de
Max Planck Institute for Astronomy, Heidelberg


Original publication

Silvia Belladitta et al.
Euclid: A UV-faint quasar in a highly luminous star-forming host galaxy at z≈7.7
Astronomy & Astrophysics (2026)

DOI

Daming Yang (Leiden Observatory) et al.
Euclid: Discovery of 31 new quasars at 6.6 < z < 7.8
Astronomy & Astrophysics (2026)

DOI

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Monday, July 13, 2026

A cosmic construction project

A galaxy cluster in deep space. It is filled with elliptical galaxies: small, bright white glowing ovals. The two largest elliptical galaxies, left and right of center, are bright cores that radiate light. Unrelated, distant galaxies are scattered around as red smudges and dots.Many of these are stretched out into red arcs and lines by the galaxy cluster’s strong gravity, creating multiple images in places. Numerous spiral galaxies and bright stars appear in the foreground. Credit: ESA/Webb, NASA & CSA, S. Fujimoto


In today’s Picture of the Month from the NASA/ESA/CSA James Webb Space Telescope we are taken on a visit to a building site of significant scale. The project is a galaxy cluster named MACS J0553.4-3342, located in the constellation Columba (the Dove).

MACS J0553.4-3342 is situated at a redshift of 0.412. Redshift is a measure of how much the cluster’s light has been stretched by the expansion of the Universe over the course of its long journey to Webb’s mirrors; this unassuming number tells us that we are seeing MACS J0553.4-3342 as it was 4.4 billion years in the past. But for a galaxy cluster, this is relatively young. In fact, observations with the NASA/ESA Hubble Space Telescope and other telescopes show a cluster still in the process of being built.

MACS J0553.4-3342 is composed of two sub-clusters — roughly equal in mass — that are actively merging. The two subclusters have already slammed through each other and travelled over one million light-years apart, but they will eventually come back together again and again until they finally merge. The construction process is messy, and MACS J0553.4-3342 is filled with extremely hot gas that radiates powerful X-rays. Each subcluster is anchored on an immensely bright and massive elliptical galaxy, which are easily identifiable as the two brightest points in the centre of this scene with the largest glowing halos around them. The many smaller white elliptical galaxies are bound to one of the two subclusters by gravity, and will be incorporated into the final galaxy cluster. This image also features many foreground galaxies — spirals and dusty discs that are unrelated to MACS J0553.4-3342 — and prominent bright stars in our own Milky Way galaxy.

Even mid-way through its construction, the titanic clumps of matter swirling around in this galaxy cluster have built a device that is already very useful for us here on Earth: a gravitational lens. The extreme and concentrated mass in MACS J0553.4-3342 curves light with its gravity, similar to how a glass lens bends and focuses light. In this image you can see prominent orange, stretched-out arcs alongside each of the subclusters. These arcs are images of distant background galaxies, whose light has been warped by the galaxy cluster’s gravitational pull. The arc on the left side, three bright spots joined together, is actually three images of a single background galaxy! A forest of smaller arcs and lines are scattered across the image too; such a fantastic view appears in few other places in the Universe.

Look in the right spot, however, and this galaxy cluster turns from a distorting funhouse mirror into a precision scientific device. The gravitational lensing focuses light, magnifying objects and enhancing their brightness so if they lie in exactly the right place, background galaxies and even individual stars that would have been far too faint and distant to spot will be made visible. By carefully mapping out the mass of the cluster, researchers can reconstruct where and how strongly it distorts light from our point of view, then search for serendipitously-magnified distant objects to study. The arcs we can see in MACS J0553.4-3342 already show a few galaxies from less than a billion years after the Big Bang.

This image, taken with Webb’s Near-Infrared Camera (NIRCam), stems from a survey programme named VENUS (#6882). Astronomers aimed to create a collection of deep, high-quality images of massive galaxy clusters like MACS J0553.4-3342 across a wide range of infrared wavelengths, greatly expanding the area covered by Webb’s sensitive instruments. Researchers can then scour the clusters for distant and faint objects that have been brightened through gravitational lensing, from young galaxies and low-mass black holes to supernova explosions and individual stars. Gravitational lensing has been key to many of Webb’s most dramatic discoveries in recent years, and having many more examples of it allows us to systematically study the distant past and the evolutionary stages of the galaxies, stars and black holes we see today.



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Sunday, July 12, 2026

Distant Galaxies: Dead or in Disguise?

This image from the 2-metre Atacama Pathfinder Experiment telescope shows starburst galaxies so distant that their infrared emission has been redshifted to submillimeter wavelengths. Credit: ESO, APEX (MPIfR/ESO/OSO), A. Weiss et al., NASA Spitzer Science Center

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.

Figure 1: UVJ colour–colour diagram, which uses galaxy colours in the ultraviolet (U), visible (V), and near-infrared (J) to identify quenched galaxies. The five ultramassive galaxies (UMGs) studied here (filled cyan circles) lie firmly in the quenched region (QG), consistent with a lack of ongoing star formation. Crosses indicate galaxies undetected in ALMA dust emission, while other massive galaxies at similar redshifts are shown in grey for comparison. Credit: Chang et al. 2026

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 Mdust/Mstar < 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 Mdust/Mstar = 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.

Figure 2: The ratio of dust mass to stellar mass versus redshift for massive quenched galaxies (QGs). This quantity measures how dust rich a galaxy is compared to its stellar mass. The ultramassive galaxies in this study (cyan pentagons) fall well below the dust content expected for star-forming galaxies (solid blue line), highlighting their extreme dust deficiency. Adapted from Chang et al. 2026

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!


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.

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Saturday, July 11, 2026

NSF VLA Maps a Hidden Hydrogen Shell Around the Orion Nebula

Radio emission from neutral hydrogen atoms in the direction of the Orion Nebula, the most nearby regions of high-mass star formation. The red colors show the 21-cm emission from hydrogen, resolved for the first time at this level of detail by observations from the Neutral Atomic Hydrogen in the Solar Neighborhood (NeAtHood) project, led by Juan Diego Soler from the University of Vienna. The cyan colors show the emission from warm interstellar dust in near-infrared light. Credit: Juan D. Soler, University of Vienna, with data from the NRAO's Jansky VLA and NASA's Wide-field Infrared Survey Explorer (WISE).
 Hi-Res File

New view of a familiar nebula
The Orion Nebula is perhaps the best known nebula, yet new discoveries continue to emerge from observations across all wavelengths of the electromagnetic spectrum. Long known to be a region of active star formation, astronomers using the U.S. National Science Foundation Very Large Array (NSF VLA) have resolved the emission from neutral atomic hydrogen that elucidates how the young stars in Orion are shaping their surrounding neighborhood.

A team of astronomers led by Juan D. Soler of the University of Vienna used the NSF VLA, operated by the U.S. National Science Foundation’s National Radio Astronomy Observatories (NSF NRAO), to obtain high-resolution observations of the emission from neutral hydrogen atoms (HI) at 21 centimeters wavelength. Neutral atomic hydrogen, or H I, is traced by faint radio emission at a wavelength of 21 centimeters. Mapping that emission at high angular resolution is challenging, but the NSF VLA’s interferometric design makes it possible to resolve the structure of nearby star-forming regions.The NSF VLA, therefore, proved to be the best possible instrument for the task, Soler explains. “The NSF VLA is a very unique instrument. It is fundamental, offering the best resolution that we can get in HI from the northern hemisphere. We cannot do this with any other instrument.”

Measuring the bubble directly
When Soler and his team looked deep within the Orion Nebula, they focused on a previously identified expanding bubble formed by young stars. These past observations used tracers such as CII as a proxy for the hydrogen and offered an estimate of the mass associated with star formation. Because Soler’s team was able to observe the HI directly, their data provided a more direct estimate of the bubble’s mass,improving measurements by a factor of ten. “Measuring mass is fundamental,” Soler says, “because it tells us how efficiently these newly formed stars shape their environment with wind and radiation.”

Furthermore, the data obtained by Soler’s team also map the neutral atomic hydrogen in the vast molecular clouds within the Orion Nebula. Soler describes this interrelationship: “Talking about molecular clouds without talking about HI, is like talking about islands without ever mentioning the sea. It turns out that as we’re resolving the sea, we’re finding phenomena like this bubble that are shaping and connecting those molecular clouds. We imagine them as separate objects, not as if they were islands, completely isolated; in fairness, they’re more like archipelagos.”

First result from NeAtHood
These results, published in Astronomy & Astrophysics, are the first within a larger project called Neutral Atomic Hydrogen in the Solar System Neighborhood (NeAtHood), which aims to continue observing other nearby molecular clouds within star-forming regions visible from the northern hemisphere to produce arcminute-resolution HI maps. Soler looks to the possibility of future observations both within this program and beyond, saying, “[The bubble] is the kind of thing that should be there, but we were not expecting to see this so clearly. So now I wonder, what other surprises are hiding in the data? And in the future, the Next-Generation VLA (ngVLA) is going to target even more distant regions in the Milky Way.”



Links: Scientific Paper


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