NASA Telescopes Spot Surprisingly Mature Cluster in Early Universe

JADES-ID1
Credit X-ray: NASA/CXC/CfA/Á Bogdán; Infrared (JWST): NASA/ESA/CSA/STScI;
Image Processing: NASA/CXC/SAO/P. Edmonds and L. Frattare

JPEG (187.8 kb) - Large JPEG (2.8 MB) - Tiff (13.4 MB) - More Images

A Tour of JADES-ID1 - More Videos

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A galaxy cluster pulling itself together has been spotted at a much earlier time in the universe than expected.

This “protocluster” is located about 12.7 billion light-years from Earth, or only about 1 billion years after the big bang.

Astronomers needed to combine data from NASA’s Chandra and James Webb Space telescopes to find and identify this protocluster.

Galaxy clusters are some of the largest structures in the universe and understanding how and when they form is crucial.

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This graphic represents the discovery of what may be the most distant protocluster ever found, as described in our latest press release. By using NASA’s Chandra X-ray Observatory together with the James Webb Space Telescope (JWST), astronomers have netted an important piece in the history of the universe: when galaxy clusters, the largest structures held together by gravity, begin to form.

The main panel contains an infrared image from the JWST Advanced Deep Extragalactic Survey (JADES), a deep infrared imaging project that used more than a month of the telescope’s observing time. The white box outlines X-rays (blue) seen with Chandra.

The newly-discovered protocluster, dubbed JADES-ID1, is located about 12.7 billion light-years from Earth, or just about a billion years after the big bang. It has a mass of about 20 trillion suns and two important characteristics of a protocluster: a large number of galaxies held together by gravity (Webb sees at least 66 potential members) and a huge cloud of hot gas (detected by Chandra). So that only X-rays from the protocluster are included, only X-rays inside the white box are shown. The annotated version of the image shows circles where astronomers find some of the individual galaxies in JADES-ID1.

Most models of the universe predict that there likely would not be enough time and a large enough density of galaxies for a protocluster of this size to form at this epoch in the early universe. The previous record holder for a protocluster with X-ray emission is seen much later, about three billion years after the big bang. Therefore, the discovery of JADES-ID1 will force scientists to re-examine their ideas for how galaxy clusters — gigantic collections of galaxies, hot gas, and dark matter — first appeared in the universe.

To find JADES-ID1, astronomers combined deep observations from both Chandra and Webb. By design, the JADES field overlaps with the Chandra Deep Field South, the site of the deepest X-ray observation ever conducted. This field is thus one of the few in the entire sky where a discovery such as this could be made. The researchers found five other proto-cluster candidates in the JADES field, but only in JADES-ID1 are the galaxies seen to be embedded in hot gas. Only JADES-ID1 possesses enough mass for an X-ray signal from hot gas to be expected.

A paper describing these results appears in the latest issue of the journal Nature and is available here. The authors of the study are Akos Bogdan and Gerritt Schellenberger (Center for Astrophysics | Harvard & Smithsonian) and Qiong Li and Christopher Conselice (University of Manchester in the United Kingdom).

The earlier study led by Li was published in the Monthly Notices of the Royal Astronomical Society.

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Quick Look: NASA Telescopes Spot Surprisingly Mature Cluster in Early Universe

Source: NASA’s Chandra X-ray Observatory

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Visual Description:

This composite image features what may be the most distant protocluster ever found; a region of space where a large number of young galaxies are being held together by gravity and hot gas. The image is presented twice, once with, and once without, annotations.

The image includes scores of glowing dots and specks of light, in white and golden hues, set against the blackness of space. This layer of the composite visual is from a deep infrared imaging project undertaken by the James Webb Space Telescope. The specks range from relatively large oval galaxies with discernible spiral arms, and glowing balls with gleaming diffraction spikes, to minuscule pinpoints of distant light. Several of those pinpoints have been circled in the annotated image, as they are part of the distant protocluster.

Layered onto the center of this image is a neon blue cloud. This cloud represents hot X-ray gas discovered by Chandra in the deepest X-ray observation ever conducted. In the annotated image, a thin white square surrounds the blue cloud. This represents Chandra’s field of observation. The X-rays from the distant protocluster located within this box are included in the composite image.

The protocluster, dubbed JADES-1, has a mass of about 20 trillionsuns. It is located some 12.7 billion light-years from Earth, or just a billion years after the big bang. The discovery of a protocluster of this size, at this epoch in the early universe, will lead scientists to re-examine their ideas for how galaxy clusters first appeared in the niverse.

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Fast Facts for JADES-ID1:

Credit: X-ray: NASA/CXC/CfA/Á Bogdán; Infrared (JWST): NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/P. Edmonds and L. Frattare
Release Date: January 28, 2026
Scale: Image is about 54 arcsec (1.1 million light-years) across.
Category: Groups & Clusters of Galaxies
Coordinates (J2000): RA 3h 32m 31.75s | Dec -27° 46´ 51.5"
Constellation: Fornax
Observation Dates: 99 observations from May 2000 to Feb 2016
Observation Time: 1743 hours 36 minutes (72 days, 15 hours, 36 minutes)

Obs. ID: 441, 582, 1672, 2239, 2312, 1213, 2405, 2406, 2409, 8591-8597, 9575, 9578, 9593, 9596, 9718, 12044-12055, 12123, 12128, 12129, 12135, 12137, 12138, 12213, 12218-12223, 12227, 12230-12234, 16175-16191, 16450-16463, 16620, 16641, 16644, 17416, 17417, 17535, 17546, 17552, 17556, 17573, 17633, 17634, 17677, 18709, 18719, 18730

Instrument: ACIS
References: Bogdán, Á; et al. 2026, Nature, in press. Available here.
Color Code: X-ray: blue; Infrared: red, green, blue
Distance Estimate: About 12.7 billion light-years from Earth (z~5.7)

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'Red Potato' galaxy discovered by astronomers

Galaxy MQN01 J004131.9-493704 "Red Potato" at z=3.25 and its surrounding cool Lyα-emitting gas reservoir.
Credit: arXiv (2026). DOI: 10.48550/arxiv.2601.20473

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Using the James Webb Space Telescope (JWST), an international team of astronomers has discovered a new massive and quiescent red galaxy, which they dubbed "Red Potato." The discovery was reported in a research paper published January 28 on the arXiv pre-print server.

A potato in the cosmic web

A team of astronomers led by Weichen Wang of the University of Milan, Italy, has recently observed a gas-rich cosmic web node at a redshift of approximately 3.25, designated MQN01. In general, such cosmic web nodes and protoclusters at high redshifts are known to host rich reservoirs of cool and molecular gas. Therefore, these structures are expected to be sites of exceptionally efficient formation of massive galaxies via gas accretion.

By investigating MQN01 with JWST's Near Infrared Camera (NIRCam) and Near Infrared Spectrograph (NIRSpec), Wang's team has serendipitously discovered a new massive red galaxy. Due to its morphology and color, they named it "Red Potato."

"In this work, we present the discovery of a massive quiescent galaxy in a gas-rich environment of a cosmic web node or protocluster at z ∼ 3.2, identified and spectroscopically confirmed from a JWST program," the researchers write in the paper.

Massive and quiescent

The Red Potato, or MQN01 J004131.9-493704, has a half-light radius of about 3,260 light years and stellar mass of 110 billion solar masses. The molecular gas mass of the galaxy was calculated to be less than 7 billion solar masses, which yields a molecular gas fraction smaller than 0.06.

The non-detection of carbon monoxide and sodium D-lines indicate that the Red Potato is poor in molecular and neutral gas. Moreover, no gas outflows have been detected from the galaxy. In general, the Red Potato galaxy appears to be a dispersion-dominated system according to the kinematics of ionized gas.

The study found that Red Potato has a star-formation rate (SFR) at a level of 4.0 solar masses per year, which is at least one dex below the star-forming main sequence (SFMS). This is a relatively low SFR given that the galaxy is located at the center of a large reservoir of cool circumgalactic medium (CGM).

X-ray jet causing gas turbulence

The stellar velocity dispersion of Red Potato was found to be 268 km/s, suggesting elevated levels of gas turbulence in the CGM. Furthermore, deep X-ray data point to the presence of an extended X-ray jet which most likely emanates from a neighboring luminous X-ray active galactic nucleus (AGN), indicating a certain form of jet-mode feedback acting on the Red Potato's CGM.

"We argue that the jet feedback may have led to increased CGM turbulence around the Red Potato and thus have reduced the gas accretion onto the galaxy, which is indicated by the high gas velocity dispersion measured from the Lyα and Hα line profiles," the authors of the paper conclude.

Source: Phys.org/Space News

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Publication details

Weichen Wang et al, A Quiescent Galaxy in a Gas-Rich Cosmic Web Node at z~3, arXiv (2026). DOI: 10.48550/arxiv.2601.20473

Journal information: arXiv

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Explore further

SXDF-NB1006-2 is a young starburst galaxy experiencing ionized gas outflows, observations find

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The Winner of the Cosmic Speed-Eating Contest

Artist's impression of a luminous quasar surrounded by a swirling accretion disk.
Credit: ESA/Hubble, NASA, M. Kornmesser; CC BY 4.0

Title: X-Ray Investigation of Possible Super-Eddington Accretion in a Radio-Loud Quasar at z = 6.13
Authors: Luca Ighina et al.
First Author’s Institution: Harvard–Smithsonian Center for Astrophysics and Italian National Institute for Astrophysics
Status: Published in ApJL

Quasars are some of the most extreme objects in the entire universe. Despite being as far as tens of billions of light-years away, they nonetheless can appear as bright as some stars in our own Milky Way. To put their brightness in perspective, one just has to consider the Sun. Compared to puny human scales, our star is a truly gargantuan object. It’s a fully functional fusion reactor, churning hydrogen into helium in its core and outputting an unfathomable amount of energy in the process. This glowing furnace is so bright that it can cook us with the heat of an oven during the day, even at a distance of more than 90 million miles (about 8 light-minutes). That distance dramatically dilutes the radiation of the Sun by the time it reaches us, as we only receive a small sliver of its total output, and yet we can still feel its heat pounding down on us when we stand beneath a clear summer sky.

However, if one were to move the Sun about 30 light-years away, it would appear completely unremarkable. You’d need to be under relatively dark skies to even spot it! The vastness of space would simply crush the output of our solar engine; however, if you place a luminous quasar at that same 30 light-year distance, its searing radiation would seem to effortlessly cross the cosmic gulf looming between the stars, scorching us relentlessly with the same heat as the Sun does today. The power of a quasar simply puts our star to shame.

Still, even quasars have limits. The source of power for these objects is a supermassive black hole. The supermassive black hole that lives at the center of our Milky Way is currently dormant. However, many supermassive black holes (especially in the early universe) actively gulp down matter, releasing tremendous energy that escapes in the form of radiation across the electromagnetic spectrum. The escaping photons bump into particles on their way out, exerting an outward pressure. If enough light is unleashed by the quasar, this pressure will actually balance against the pull of gravity, cutting off the food supply for the black hole. This negative feedback loop means that a given quasar has an upper limit to its brightness, called the Eddington luminosity, and to the speed at which it accretes matter, called the Eddington rate. The authors of today’s bite examine a particularly misbehaved quasar that seems to violate even these extreme limits.

It’s a Bird! It’s a Plane! It’s a Jet?

The authors observed the quasar RACS J032021.44−352104.1 (RACS J0320−35 for short) with several radio observatories, including the Giant Metrewave Radio Telescope, the Australia Telescope Compact Array, and the Australian Large Baseline Array. Combining this data with publicly available observations, they find that the source is “radio-loud,” or bright at very long wavelengths. Typically, this kind of emission is expected to be generated by powerful jets that are ejected from the poles of a quasar. For example, the authors compare this radio-loud quasar to similar sources, which show significant variability in the X-ray part of the spectrum. This is a tell-tale sign that the X-ray emission is also generated by these jets (which might come out in fits and spurts and thus cause fluctuations in brightness over time).

However, when the authors examine X-ray data of RACS J0320−35 taken by the Chandra X-ray Observatory, they find surprising results. The quasar is extremely luminous in X-rays, making it one of the brightest in the early universe. But despite the fact that it pumps out a huge number of these energetic photons, it seems to preferentially emit only the lower-energy band of X-rays and completely lacks the highest-energy emission that characterizes similar sources. In technical terms, the X-ray spectrum of RACS J0320−35 is incredibly “soft.” Moreover, this X-ray emission seems to be constant on the timescale of months, though further observations will be required to test if it varies on longer timescales. Still, the softness of the spectrum and weak variability of this system mean that its X-ray emission is unlikely to be produced by a jet.

The authors carefully consider a particular variety of jet — one that is sharply angled towards us. Since quasar jets often travel at incredible speeds, the special theory of relativity kicks in and causes strange behaviors. In particular, an effect called relativistic beaming can cause a source to appear much brighter if traveling towards the observer at extremely high speeds. However, they find that although relativistic beaming can explain the mysterious X-ray properties of RACS J0320−35, such a scenario is incompatible with its observed radio emission. Moreover, a lack of gamma-ray emission and weak variability are further pieces of evidence against the jet origin of the X-ray emission.

Figure 1: A plot showing the observed energy spectrum of RACS J0320−35 and the theoretical spectra predicted by several models. In particular, the green circles (visible light and ultraviolet (UV) emission), blue diamonds (X-ray emission), and red squares (radio emission) representthe real observations. The shaded pink region represents the predictions of a model that simulates a black hole spinning very slowly and accreting at super-Eddington rates. The model seems to match the observed X-ray and visible/UV emission excellently. However, explaining the observed radio emission might require conditions that violate the assumptions behind this scenario. Adapted from Ighina et al. 2025.

Limits Are Meant to Be Broken

The article presents one more fascinating possibility for the origin of the X-rays in this source. Some theoretical work and simulations show that if a black hole breaks the Eddington limit and starts accreting matter at “super-Eddington rates,” the X-ray spectrum that results can be incredibly soft. The authors find excellent agreement between the observations and the predictions from a particular model that simulates a very slowly spinning black hole (see Figure 1). This scenario seems to be a promising explanation for the X-ray emission in RACS J0320−35, which is extremely exciting for several reasons.

Many astronomers are considering super-Eddington accretion to explain the masses of early quasars and their fainter counterparts, called active galactic nuclei. Because supermassive black holes are supposed to have a cap on their accretion rate (the Eddington limit), the earliest black holes in the universe should only have been able to reach large sizes after sufficient time had passed. Astonishingly, observations from JWST are finding massive active galactic nuclei everywhere in the early universe, which seems to violate this — these black holes appear astonishingly massive despite existing for only a fraction of the universe’s current age. However, if early black holes could grow faster than expected by undergoing super-Eddington accretion, this tension might be resolved.

Despite the promising initial results of this model, there are a few caveats to the results presented in today’s article. For example, the radio jets observed from this source require a rapidly spinning black hole, which conflicts with the model assumptions. The authors note that a radio jet can be very far from a black hole, tracing its past activity. In fact, this jet may have actually spun down the central supermassive black hole by extracting energy from it, a fascinating possibility that will require both further observations and simulations to explore. Today’s bite shines a brilliant light on this possibility by analyzing RACS J0320−35, a fascinating quasar in the early universe and a stunning example that cosmic limits are meant to be broken.

Original astrobite edited by Veronika Dornan

Source: American Astronomical Society/AAS-Nova

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About the author, Ansh Gupta:

I’m an astronomy graduate student at the University of Texas at Austin working with Steven Finkelstein. I use data from JWST to study the formation and growth of the first galaxies and black holes in the universe. In my spare time, I enjoy playing piano, reading, and making YouTube videos.

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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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AES Andes announces cancellation of INNA, the industrial complex planned near Paranal

PR Image eso2602a
Cerro Paranal and the Milky Way above it

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AES Andes announced that it will step back from the megaproject INNA, planned to be located near the European Southern Observatory’s (ESO’s) Paranal Observatory. ESO welcomes this announcement and expects that the project will be withdrawn from Chile's Environmental Assessment Service (SEA) soon, which would formally confirm INNA is not going ahead.

“When the cancellation is confirmed, we’ll be relieved that the INNA industrial complex will not be built near Paranal,” said ESO Director General Xavier Barcons. “Due to its planned location, the project would pose a major threat to the darkest and clearest skies on Earth and to the performance of the most advanced astronomical facilities anywhere in the world.”

AES Andes, a subsidiary of the US company AES Corporation, announced on Friday 23 January that they had decided to discontinue INNA, a green hydrogen and green ammonia project, to focus on their renewable energy portfolio instead. A detailed technical analysis by ESO last year revealed that INNA would cause severe, irreversible damage to the dark skies of Paranal and to the capacity of its facilities to operate as designed. The most significant impacts, affecting facilities such as the Very Large Telescope (VLT), the VLT Interferometer (VLTI), the Extremely Large Telescope (ELT), and CTAO-South, would be caused by light pollution, micro-vibrations, dust, and an increase of the air turbulence in the area.

“As we have said before, ESO and its Member States are fullysupportive of energy decarbonisation and initiatives that ensure a more prosperous and sustainable future. Green-energy projects — and other industrial projects that drive national and regional development — are fully compatible with astronomical observatories, if the differentfacilities are located at sufficient distances from one another,” says Barcons.

The INNA case and its proposed location highlight the urgent need to establish clear protection measures in the areas around astronomical observatories. Such measures are essential to allow astronomical observatories to continue operating, particularly in a region widely regarded as the best in the world for optical astronomy facilities, owing to the exceptional darkness of the skies over northern Chile.

“We will continue to work in close collaboration with local, regional, and national authorities to protect the dark skies of northern Chile, an irreplaceable natural heritage that is essential for advancing our understanding of the Universe and to enable world-class astronomy for the benefit of Chile and the global scientific community,” says Itziar de Gregorio-Monsalvo, ESO’s Representative in Chile.

“It has been incredibly reassuring to see so many people in Chile and around the world care deeply about, and actively speak up for, the protection of dark and quiet skies in the context of the INNA project,” says Barcons. “We are sincerely grateful for this engagement and solidarity. It gives us confidence that, by working together, we can continue to protect dark and quiet skies in Chile and elsewhere — for astronomy research and for humankind.” Since the project was submitted to SEA in December 2024, members of the astronomy community in Chile, in ESO’s Member States and beyond, political leaders and authorities at international, national, regional and local level, as well as countless members of the public, have made their voices heard in support of this shared goal.

ESO will continue to intensify its efforts to ensure that the pristine skies of Paranal remain the world’s best window to observe the Universe, and is also committed to the broader fight against light pollution and satellite interference, helping secure the natural heritage of dark and quiet skies around the world for future generations.

Source: ESP/News

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More information

AES Andes announced that it will step back from the megaproject INNA, planned to be located 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 Chilean partners and society.

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Links

• Executive summary of ESO technical analysis on the impact of the INNA project
• Photos of Paranal


• INNA infographics


• Previous press releases on INNA: January 2025; March 2025

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Contacts:

Francisco Rodríguez
Head of ESO Communications Chile
Santiago, Chile
Tel: +56 2 2463 3151
Email: francisco.rodriguez@eso.org

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

Connect with ESO on social media

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Testing Einstein’s theory of relativity with the clearest gravitational-wave signal yet

Visualization of a binary black hole ringdown consistent with the gravitational-wave event GW250114.The gravitational waves are separated into two modes of the ringing remnant black hole, identified in the observation: the fundamental mode (green) and its first overtone (red). It also shows a predicted third tone (yellow) that the data places limits on. Visualization performed at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute), based on a numerical relativity simulation of the Simulating Extreme Spacetimes (SXS) Project. Credit: H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), K. Mitman (Cornell University)

Ringing Black Hole Animation (GW250114)
Credit: H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), K. Mitman (Cornell University)

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To the point:

• Relativity put to the test: Relativity put to the test: A LIGO-Virgo-KAGRA team has conducted some of the most precise tests of Einstein’s theory of general relativity. The results were published in Physical Review Letters today.


• Einstein holds fast: In all tests, the observations match the theory’s predictions. In some cases, the tests based on this signal alone are two to three times more stringent than those obtained by combining data from dozens of other signals.


• The clearest signal: The team used data from GW250114, the strongest gravitational-wave signal ever detected from the merger of two black holes.


• Like a bell: For the first time, detailed analyses of the complete signal and the ringdown phase, which occurs shortly after the merger, have identified or constrained three gravitational-wave tones.

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An international team, with key contributions from AEI researchers, identified three gravitational-wave tones in GW250114 for the first time and conducted the most stringent tests of general relativity.

Relativity put to the test

A year ago, almost to the day, the LIGO-Virgo-KAGRA collaboration observed by far the clearest gravitational-wave signal seen to date. GW250114 came from a coalescence of black holes with masses between 30 to 40 times that of our Sun about 1.3 billion light-years away.

“This signal has already proven to be a great boon for a test of the nature of black holes and of Hawking’s area law,” says Alessandra Buonanno, director of the Astrophysical and Cosmological Relativity department at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI) in the Potsdam Science Park. “Now we have gone one step further and published some of the most stringent limits on deviations from Einstein’s theory of general relativity using GW250114.”

Additional analysis of the GW250114 data was published today in Physical Review Letters. The writing team included several AEI members: Alessandra Buonanno, who served as chair, and Lorenzo Pompili, Elisa Maggio, and Elise Sänger, who conducted several of the analyses reported in the publication.

Because GW250114 was observed so clearly, it can be compared in much greater detail to predictions from Einstein’s theory of relativity than other signals. This makes it possible to test whether general relativity holds true in the extreme conditions of a black hole coalescence, where strong gravitational fields meet rapidly changing dynamics. Any deviations from the predictions of general relativity could hint at new physics beyond Einstein’s theory.

Like a struck bell

The international research team obtained some of the key results using a method known as black hole spectroscopy. For this, the team focused on the ringdown of the GW250114 signal – the phase when the black hole settles into its final state right after the merger – and the characteristic spectrum of gravitational-wave modes, or tones, emitted during this phase. These tones resemble the sounds a bell makes when struck: Each tone is described by two numbers: its frequency and the rate at which it is fading. Measuring the spectrum of the tones and their fading times is called black hole spectroscopy.

For the first time, a triad of gravitational-wave tones

For the first time, researchers at the AEI in Potsdam found a third tone in the signal’s ringdown phase using a new data analysis tool they developed.

“Our analysis tool, originally proposed in 2018, takes into account the complete black-hole coalescence and makes no prior assumptions about the tones emitted during the ringdown phase,” explains Elisa Maggio, a former Marie Curie Fellow in the Astrophysical and Cosmological Relativity department and now an INFN Researcher in Rome, Italy. Maggio and Pompili collaborated on developing the most recent version of the tool and conducting the analysis. “By incorporating information from the entire signal, we constrained a higher-pitched tone at approximately twice the fundamental frequency for the first time, once again matching theoretical predictions.”

Together, the two tests – one looking at the ringdown alone and the other considering the full signal – complement each other. Once again, they empirically vindicate the rotating black hole solution discovered in 1963 by Roy Kerr.

One signal beats dozens of others

The research team also examined an earlier phase of the clearly observed black hole coalescence when the two black holes were orbiting each other more slowly.

“We used a flexible, theory-independent method developed earlier at the AEI to determine how much the gravitational-wave signal deviated from the predictions of general relativity early in the coalescence,” says Elise Sänger, a PhD student in the Astrophysical and Cosmological Relativity department who conducted the analysis. “Remarkably, using data from this one clearly observed signal alone allows us to set some of the most stringent constraints on possible deviations from general relativity.”

The constraints derived using the AEI-developed model are two to three times more stringent than those obtained by combining data from dozens of signals in the latest fourth Gravitational-Wave Transient Catalogue (GWTC-4.0).

Only the beginning

“These results demonstrate the great scientific value of accurate waveform models and ophisticated data analysis techniques,” says Alessandra Buonanno. “But this is only the beginning. Future observing runs will allow us to detect signals like GW250114 more frequently and more clearly. Each one will open new avenues for testing Einstein’s theory and searching for new physics.”

Source: Max Planck Institute for Gravitational Physics/News

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Media contact:

Dr. Elke Müller
Press Officer AEI Potsdam, Scientific Coordinator
Tel: +49 331 567-7303
elke.mueller@aei.mpg.de

Science contacts:

Prof. Dr. Alessandra Buonanno
Director | LSC
Principal Investigator
Tel: +49 331 567-7220
Fax: +49 331 567-7298
alessandra.buonanno@aei.mpg.de
Homepage of Alessandra Buonanno

Dr. Elisa Maggio
INFN Researcher
elisa.maggio@aei.mpg.de
Istituto Nazionale di Fisica Nucleare, Rome

Dr. Lorenzo Pompili
Research Fellow
Lorenzo.Pompili@nottingham.ac.uk
University of Nottingham, School of Mathematical Sciences

Elise Sänger
PhD Student
elise.saenger@aei.mpg.de

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Publication

The LIGO Scientific Collaboration; the Virgo Collaboration; the KAGRA Collaboration; Abac, A.; Abouelfettouh, I.; Acernese, F.; Ackley, K.; Adhicary, S.; Adhikari, D.; Adhikari, N. et al.

Black Hole Spectroscopy and Tests of General Relativity with GW250114. Physical Review Letters 136, 041403 (2026)

MPG.PuRe - DOI - pre-print - publisher-version

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Further information

LIGO Science Summary
of the publication “Black hole spectroscopy and tests of general relativity with GW250114”

MPG.PuRe - DOI - pre-print - publisher-version

more

Ten years of gravitational-wave astronomy and the clearest signal yet

September 10, 2025
The LIGO-Virgo-KAGRA collaboration and the Max Planck Institute for Gravitational Physics celebrate the anniversary and present new, exciting results.

more

LIGO-Virgo-KAGRA Collaboration successfully wraps up its fourth Observing Run

November 19, 2025
Further exciting results anticipated from O4’s remaining parts

more

Doubling the gravitational-wave transient catalogue

August 26, 2025

LIGO-Virgo-KAGRA researchers at the Max Planck Institute for Gravitational Physics and at Leibniz University Hannover make significant contributions to detect and analyze new gravitational-wave candidates

more

Brito, R.; Buonanno, A.; Raymond, V.
Black-hole Spectroscopy by Making Full Use of Gravitational-Wave Modeling. Physical Review D 98 (8), 084038 (2018)

MPG.PuRe - DOI - pre-print

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An old puzzle solved: astronomers discover the world is flat

The average distribution of dark matter for a large number of computer simulations, each of which was required to form a Milky Way and an Andromeda Nebula (the two bright blobs at the centre) with the observed position and velocity, and also to match the observed velocity at the position of 31 nearby galaxies (cyan dots). The box size is 20 times the Milky Way-Andromeda separation with a depth of one-half this separation. Colour represents the amount of dark matter at each point, while arrows show its velocity relative to a uniformly expanding universe. The left image is looking down onto the Local Mass Sheet, while the right one views it from the side. Notice that velocities relative to a uniform Hubble flow are small in both panels in the region occupied by the cyan dots, implying that these galaxies appear to match Hubble’s Law almost perfectly in the simulated universes. © MPA

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A pan-European group of astronomers has used newly developed computer technology to solve a 100 year-old puzzle. While most galaxies in our neighborhood move away from us almost as expected for an unperturbed cosmic expansion, our nearest giant neighbour is approaching at high speed. Systematic numerical experimentation demonstrates this rapid approach is due to massive dark matter haloes surrounding both Andromeda and our own Milky Way, but this mass does not slow down somewhat more distant galaxies because its effects are counteracted by more distant dark matter which lies in a vast flattened sheet out to distances well beyond the neighboring galaxies considered.

Why is the Andromeda Nebula heading straight for us, while other nearby galaxies are receding?

It is nearly a century since the American astronomer Edwin Hubble discovered the expansion of the Universe. Distant galaxies similar to our own Milky Way move away from us at speeds that increase in proportion to their distance, reflecting the origin of the Universe in a Big Bang, an enormous explosion 14 billion years ago. Hubble already knew, however, that this is not true for our nearest giant neighbour, the Andromeda Nebula, which is 2.5 million light-years away and coming towards us at 100 kilometers per second. In 1959, two European astronomers, Franz Kahn and Lodewijk Woltjer, calculated that in order for the gravity of the two galaxies to have reversed the initial expansion, their total mass must be more than 1000 billion times the mass of the Sun – much more than the mass of all their stars put together. This was the first detection of unseen Dark Matter around our Milky Way and its neighbour.

In the 1970s and 1980s, accurate distances began to be measured for somewhat more distant galaxies. It became clear that not only are they are mostly moving away from us but that their speeds are close to those predicted by the overall cosmic expansion – starting in a “Big Bang” 14 billion years ago. Studies of galaxies at distances from 1.5 to 4 times the Milky Way-Andromeda separation found the deviations to be actually quite small – the total amount of matter required to account for these deviations out to the most distant galaxy cannot be larger than that already needed to explain the approach speed of the Milky Way and Andromeda. However, there are several other large galaxies in this region, which should contribute additional mass. Why then does the cosmic expansion around us appear so weakly perturbed?

A pan-European group of astronomers has recently used newly developed computer technology to find the solution to this puzzle. They set the machine the following task: Find representative regions of the early Universe with small deviations from uniformity that are statistically similar to the Cosmic Microwave Background, but that evolve to produce galaxies similar to the Milky Way and Andromeda, with the appropriate positions and velocities. At the same time, other nearby galaxies should show motions and positions matching those of observed nearby galaxies.

Apparently, the puzzle was not hard for the computer: it was able to find hundreds of examples satisfying all the given conditions. The average mass distribution for a large number of these is shown in the figure. In the region containing the local galaxies, motions relative to a uniform expansion are indeed small – the Hubble flow is almost unperturbed – while at larger distances material is actually moving away from the Milky Way faster than the Hubble flow.

Max Planck Institute for Astrophysics How the computer solved the puzzle can be seen in the right image of the figure, which shows a view of the same box rotated by 90 degrees. The mass is concentrated to a flattened sheet extending well beyond the region occupied by the local galaxies considered. All the galaxies are inside the sheet and even at larger distances most known galaxies are still found in a flattened distribution known as the Local Supercluster. The computer has inferred this larger structure even though it was not told about its existence. The large low-density regions above and below the sheet are also seen in the galaxy distribution and are known as the Local Voids. However, the large velocities predicted there are not observable, because in the real universe there are no galaxies there to be measured.

Thus, there are two reasons why the local Hubble flow seems so weakly perturbed despite the large combined mass of the Milky Way and Andromeda. Mass at larger distances is counteracting the gravity of the central galaxies by pulling material outwards. In addition, there are no galaxies where the predicted infall effects are large, so inflow onto the Local Sheet is hidden.

The solution to the puzzle is that the total mass distribution in our environment is at least as sheet-like as the distribution of galaxies. The world around our Local Group of galaxies is indeed flat out to distances of tens of millions of light-years.

Source: Max Planck Institute for Astrophysics/Press Releaes

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Author:

Simon White
Emeritus Director
Tel: 2211
Tel: +49 170 248 1178
swhite@mpa-garching.mpg.de

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Original publication

E. Wempe et al. The mass distribution in and around the Local Group
Nature Astronomy, 27 January 2026

Source

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Weitere Informationen

L’anomalie d’Andromède résolue : une feuille cosmique explique son mouvement et l’expansion locale
CNRS Press Release
(in French)

Een ‘platte’ omgeving van de Melkweg verklaart de beweging van nabije sterrenstelsels
Dutch press release

Gammal gåta löst: astronomer upptäcker att vårt kosmiska närområde är platt
University Stockholm press release

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NuSTAR Observes an Unusual Black Hole

An artist's illustration of hot gas from a low-mass companion star flowing into an accretion disk around the black hole. Image credit: ESO/L. Calçada. - Download Image

During the past week, NuSTAR performed multiple observations of the black hole X-ray binary (BHXB) GS 1354−64, including one observation coordinated with the JAXA/ESA/NASA mission XRISM. GS 1354−64 is unusual in several respects. Discovered in 1987 during an outburst, it has since undergone two additional outbursts (1997 and 2015), yet in both cases it “failed” to complete the canonical hard-to-soft X-ray spectral transition, observed in outbursts by other BHXB, before fading back into quiescence. In the current episode, however, the most recent NuSTAR observation indicates that the source is now transitioning toward the soft X-ray state. Optical studies of the companion star (BW Cir) have placed the system at a distance of ~27 kpc, which—if correct—would make it among the most distant known Galactic BHXBs. A preliminary analysis of the latest NuSTAR data suggests that, at this distance, the transition would be occurring at an X-ray luminosity of roughly 70% of the Eddington limit (the luminosity at which radiation pressure balances gravity for accreting material). This is striking because BHXBs typically undergo the hard-to-soft transition at ≲10% of the Eddington limit. The NuSTAR dataset will therefore be used to test several possibilities: is the source substantially closer than we thought it was (e.g., 8–10 kpc and thus less luminous), significantly more massive than currently assumed (and thus would have a higher Eddington limit), or otherwise genuinely anomalous? In addition, the combination of the high spectral resolution and broad X-ray sensitivity from the joint NuSTAR+XRISM observation will enable tighter constraints on the binary system’s spin and inclination.

Author: Oluwashina Adegoke (Postdoctoral Scholar, Caltech)

Source: NASA's Nuclear Spectroscopic Telescope Array (NuSTAR)/Weekly Highlights)

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Binary dance: a white dwarf system explains mysterious radio pulses across the Milky Way

Artistic impression of the red dwarf and white dwarf interaction of the long-period transient GPM J1839-10. Credits: D. Futselaar/Horvath, Rea, Hurley-Walker et al. 2026

The white and red spheres are the white dwarf and M-dwarf. The arrow represents the white dwarf’s rotating magnetic moment. The yellow cone is the radio beam whose brightness depends on the alignment of the white dwarf’s magnetic moment with the M-dwarf. Below is the radio flux density detected on Earth. Animation from interactive by Csanad Horvath.

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Investigating the nature of long-period transients, a newly discovered class of radio transients, can widen our knowledge on how plasmas and magnetic fields interact in extreme environments.

An international team observed a long-period transient non stop for 2 days in a study published in Nature Astronomy.

Over the past four years, a new class of signals from the Universe has captured astronomers’ attention. These events originate from galactic objects known as long-period transients (LPTs), whose nature remains unknown. They appear as repeating bright radio pulses with unusually long periods. So far, around 12 such sources have been discovered, but their origin and the mechanisms that generate their emission are still unclear. A new study published in Nature Astronomy, led by ICRAR PhD student Csanad Horvath, investigates the longest-lived LPT known.

GPM J1839-10 is the name of the longest-known LPT, with a 21- min period, observed in the Milky Way. It has now been demonstrated to be a binary system hosting a white dwarf. This system consists of a spinning white dwarf (a stellar remnant) and a red dwarf (a star smaller than the Sun). It adds scientific evidence to two previous studies that proposed other LPTs as the same type of binary systems, showing that most LPTs may share a similar origin. The exact physics behind the bright radio pulses of these sources has now been related with the interaction between the white dwarf pulsar magnetic field and the wind of the companion star.

“This work demonstrates a novel way of shedding light on the nature of LPTs, a field that started only 3 years ago and has been revealed to be key to understanding the radio transient sky”, says Nanda Rea, from the Institute of Space Sciences (ICE-CSIC) and the Institute of Space Studies of Catalonia (IEEC), co-author of the study.

These findings may represent the first steps toward understanding the true nature of all LPTs and, consequently, revising our knowledge of white dwarf and red dwarf binaries. “Radio emission produced by white dwarf binaries might be more prevalent and diverse than previously thought,” suggests Rea.

To carry out the study, the international team, composed of six researchers from astronomy research institutes in Australia and Spain, conducted a continuous 40-hour observation of GPM J1839−10. This required three radio telescopes operating sequentially at different locations around the world: the MeerKAT telescope in South Africa, CSIRO’s ASKAP radio telescope on Wajarri Yamaji Country in Australia, and the Karl G. Jansky Very Large Array (VLA) in the United States of America. “Each telescope handed the source to the next as the Earth rotated to keep the source in view,” explains Csanad Horvath, a PhD student at the Curtin University node of ICRAR, who led the work and spent a month at ICE-CSIC to finalize the analysis.

This allowed the team to record the signal pattern with high precision for subsequent analysis. They discovered that the radio pulses arrive in groups of 4 or 5 and that they come in pairs separated by two hours. A pattern that repeats every 9 hours, suggesting orbital motion with such period happens within the source system.

Using a theoretical model based on the same geometric framework proposed for white dwarf pulsars, the team accurately reproduced the intermittent emission and double-pulse structure. This strongly supports the interpretation that the LPT is a white dwarf–red dwarf binary system, and allowed to measure the system characteristics as the orbit, the inclination in our line of sight and star masses. In this scenario, radio pulses are produced whenever the magnetic axis of the spinning white dwarf, the imaginary line connecting its two magnetic poles, intersects the stellar wind of its companion, generating a bright radio signal. In every orbit the bright radio pulses can be seen twice, with 4-5 pulses every time.

Beyond revealing the likely nature of one known LPT, the study also provides a framework to investigate many more such objects. The model applied to the growing population of LPTs and other known white dwarf binary pulsars have shown the connection between these apparently different classes as well as shed light on the evolution of magnetic properties of white dwarf and red dwarf binaries.

Source: International Center for Radio Astronomy Research (ICRAR)/News

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Publication

Horváth, Rea, Hurley-Walker, McSweeney, Perley, & Lenc (2026), ‘A binary model of long-period radio transients and white dwarf pulsars‘, Nature Astronomy. DOI: 10.1038/s41550-025-02760-y.

Adapted from a media release by Institute of Space Studies of Catalonia (IEEC)

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NASA Webb Pushes Boundaries of Observable Universe Closer to Big Bang

c

COSMOS Field MoM-z14 Galaxy (NIRCam Image)

NASA’s James Webb Space Telescope shows galaxy MoM-z14 as it appeared in the distant past, only 280 million years after the universe began in the big bang. Credit Image: NASA, ESA, CSA, STScI, Rohan Naidu (MIT); Image Processing: Joseph DePasquale (STScI)

COSMOS Field MoM-z14 Galaxy (NIRCam Compass Image)

NASA’s James Webb Space Telescope shows galaxy MoM-z14 as it appeared in the distant past, only 280 million years after the universe began in the big bang. Credit Image: NASA, ESA, CSA, STScI, Rohan Naidu (MIT); Image Processing: Joseph DePasquale (STScI

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NASA’s James Webb Space Telescope has topped itself once again, delivering on its promise to push the boundaries of the observable universe closer to cosmic dawn with the confirmation of a bright galaxy that existed 280 million years after the big bang. By now Webb has established that it will eventually surpass virtually every benchmark it sets in these early years, but the newly confirmed galaxy, MoM-z14, holds intriguing clues to the universe’s historical timeline and just how different a place the early universe was than astronomers expected.

“With Webb, we are able to see farther than humans ever have before, and it looks nothing like what we predicted, which is both challenging and exciting,” said Rohan Naidu of the Massachusetts Institute of Technology’s (MIT) Kavli Institute for Astrophysics and Space Research, lead author of a paper on galaxy MoM-z14 published in the Open Journal of Astrophysics.

Due to the expansion of the universe that is driven by dark energy, discussion of physical distances and “years ago” becomes tricky when looking this far. Using Webb’s NIRSpec (Near-Infrared Spectrograph) instrument, astronomers confirmed that MoM-z14 has a cosmological redshift of 14.44, meaning that its light has been travelling through (expanding) space, being stretched and “shifted” to longer, redder wavelengths, for about 13.5 of the universe’s estimated 13.8 billion years of existence.

“We can estimate the distance of galaxies from images, but it’s really important to follow up and confirm with more detailed spectroscopy so that we know exactly what we are seeing, and when,” said Pascal Oesch of the University of Geneva, co-principal investigator of the survey.

Intriguing Features

MoM-z14 is one of a growing group of surprisingly bright galaxies in the early universe – 100 times more than theoretical studies predicted before the launch of Webb, according to the research team.

“There is a growing chasm between theory and observation related to the early universe, which presents compelling questions to be explored going forward,” said Jacob Shen, a postdoctoral researcher at MIT and a member of the research team.

One place researchers and theorists can look for answers is the oldest population of stars in the Milky Way galaxy. A small percentage of these stars have shown high amounts of nitrogen, which is also showing up in some of Webb’s observations of early galaxies, including MoM-z14.

“We can take a page from archeology and look at these ancient stars in our own galaxy like fossils from the early universe, except in astronomy we are lucky enough to have Webb seeing so far that we also have direct information about galaxies during that time. It turns out we are seeing some of the same features, like this unusual nitrogen enrichment,” said Naidu.

With galaxy MoM-z14 existing only 280 million years after the big bang, there was not enough time for generations of stars to produce such high amounts of nitrogen in the way that astronomers would expect. One theory the researchers note is that the dense environment of the early universe resulted in supermassive stars capable of producing more nitrogen than any stars observed in the local universe.

The galaxy MoM-z14 also shows signs of clearing out the thick, primordial hydrogen fog of the early universe in the space around itself. One of the reasons Webb was originally built was to define the timeline for this “clearing” period of cosmic history, which astronomers call reionization. This is when early stars produced light of high enough energy to break through the dense hydrogen gas of the early universe and begin travelling through space, eventually making its way to Webb, and us. Galaxy MoM-z14 provides another clue for mapping out the timeline of reionization, work that was not possible until Webb lifted the veil on this era of the universe.

Legacy of Discovery Continues

Even before Webb’s launch, there were hints that something very unanticipated happened in the early universe, when NASA’s Hubble Space Telescope discovered the bright galaxy GN-z11 400 million years after the big bang. Webb confirmed the galaxy’s distance — at the time the most distant ever. From there Webb has continued to push back farther and farther in space and time, finding more surprisingly bright galaxies like GN-z11.

As Webb continues to uncover more of these unexpectedly luminous galaxies, it’s clear that the first few were not a fluke. Astronomers are eagerly anticipating that NASA’s upcoming Nancy Grace Roman Space Telescope, with its combination of high-resolution infrared imaging and extremely wide field of view, will boost the sample of these bright, compact, chemically enriched early galaxies into the thousands.

“To figure out what is going on in the early universe, we really need more information —more detailed observations with Webb, and more galaxies to see where the common features are, which Roman will be able to provide,” said Yijia Li, a graduate student at the Pennsylvania State University and a member of the research team. “It’s an incredibly exciting time, with Webb revealing the early universe like never before and showing us how much there still is to discover.”

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

Source: NASA's James Webb Space Telescope/Press Releases

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Related Links

Read more: Webb Science: Galaxies Through Time

Explore more: ViewSpace Seeing Farther: Hubble Ultra Deep Field

Video: JADES: GOODS South Fly-Through Visualization

Video: Ultra Deep Field: Looking Out into Space, Looking Back into Time

Explore more: ViewSpace Gathering Light: Hubble Ultra Deep Field

More Webb News

More Webb Images

Webb Science Themes

Webb Mission Page

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New Even Horizon Telescope Results Trace M87 Jet Back to Its Black Hole

A Hubble Space Telescope image of the giant elliptical galaxy M87 with its blowtorch-like jet. The visible part of this giant stream of particles spans around 3000 light-years. © NASA, ESA, A. Lessing (Stanford University), E. Baltz (Stanford University), M. Shara (AMNH), J. DePasquale (STScI)

At 230 GHz (bottom), data from the EHT reveal the fine structure of the ring surrounding the supermassive black. © Bottom: Saurabh et al.: “Probing jet base emission of M87* with the 2021 Event Horizon Telescope observations”, Astronomy & Astrophysics 705 (2026), Figure 6. Upper Right: Lu, R.-S. et al.: “A ring-like accretion structure in M87 connecting its black hole and jet”. Nature 616 (2023), Figure 1

Selected sites from the 2021 EHT observing campaign, highlighting additional stations: the 12−m Kitt Peak (KP) Telescope, USA and the NOrthern Extended Millimeter Array (NOEMA), France. This introduces two critical intermediate-length baselines to the Submillimeter Telescope (SMT), USA and IRAM 30−m, Spain, providing sensitivity to emission structures close to the base of the jet. © Saurabh/MPIfR

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To the point:

• Recently published data from the Event Horizon Telescope (EHT) of the galaxy Messier 87 facilitate new insights into the direct environment of the central supermassive black hole.

• Measured differences in the radio light on different spatial scales can be explained by the presence of an as of yet undetected jet at frequencies of 230 Gigahertz at spatial scales comparable to the size of the black hole.

• The most likely location of the jet base is determined through detailed modeling.

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Observations with the Event Horizon Telescope enable researchers to localize the likely base of the central outflow in a massive galaxy

Some galaxies eject powerful streams of charged particles—jets—from their centers into space. The prominent jet of Messier 87 (M87) in the constellation Virgo is visible over distances of 3000 light-years and can be observed over the full electromagnetic spectrum. It is powered by the central engine, the supermassive black hole at the heart of the galaxy with a mass of around six billion times that of our Sun. The exact location around the black hole where the jets originate is still unknown. Using observations from the Event Horizon Telescope (EHT) from 2021, an international research team led by Saurabh (Max Planck Institute for Radio Astronomy, MPIfR), Hendrik Müller (National Radio Astronomy Observatory, NRAO) and Sebastiano von Fellenberg (formerly at MPIfR, currently at the Canadian Institute for Theoretical Astrophysics, CITA) has found first hints of the jet base in M87. The results are published in the current issue of the journal Astronomy & Astrophysics.

Observing different scales

M87*, the supermassive black hole at the center of the galaxy M87, is about 55 million light years (5 × 10²⁰ kilometers) away from Earth. In 2019, the first images of its shadow and the glowing ring of hot gas around it went around the world. In order to resolve these structures, radio telescopes around the world must be combined into a single virtual telescope such as the EHT. This technique is called Very Long Baseline Interferometry (VLBI). The images produced in this way are sensitive to emission on different scales, depending on the distances between telescopes (baselines): With long baselines of several thousand kilometers, the smallest structures—such as the luminous ring—around M87* can be depicted. Short baselines of a few hundred meters, on the other hand, reveal emission emanating from much larger spatial scales in M87 (the extended jet), but are blind to details near the black hole. Intermediate baselines of a few hundred to a few thousand kilometers are the important link. They can be used to establish a connection between the material around the black hole and the jet. Precisely these intermediate baselines enabled the research team to determine the probable position of the jet base. "This study represents an early step toward connecting theoretical ideas about jet launching with direct observations. Identifying where the jet may originate and how it connects to the black hole’s shadow, adds a key piece to the puzzle and points toward a better understanding of how the central engine operates", explains Saurabh.

The decisive difference

The researchers find hints to the base of the jet by comparing the measured radio intensity on different spatial scales: On short to intermediate baselines, the measured intensity is higher compared to that on long baselines. This indicates that what is observed with long baselines—the luminous ring of hot gas around the black hole—is not solely responsible for the detected radio emission. Instead, the current data show that part of the missing emission is captured on intermediate baselines. One possibility is the jet, which has not yet been observed at a radio frequency of 230 gigahertz (GHz) with the EHT.

EHT observations from 2017 and 2018 lacked the intermediate baselines to detect it. However, with the recently published data, Saurabh's team was able to show with numerous model calculations that part of the missing emission can be best explained by an additional compact region. From our perspective, this region is about 0.09 light-years away from M87* and associated with the base of the jet. The position of the region appears to coincide with the southern arm of a radio jet discovered at a different frequency (86 GHz) in 2018. "We have observed the inner part of the jet of M87 with global VLBI experiments for many years, with ever increasing resolution, and finally managed to resolve the black hole shadow in 2019. It is amazing to see that we are gradually moving towards combining these breakthrough observations across multiple frequencies and complete the picture of the jet launching region", says Hendrik Müller.

What’s next?

The current study shows that these interesting structures around M87* become visible at radio frequencies of 230 GHz with intermediate baselines. However, further observations with the EHT will be necessary to further constrain the morphology of the jet. These observations will then make it possible to not only deduce structures such as the jet base, but to image them. This opens up new possibilities for probing the direct environment of supermassive black holes and for testing theories of black hole physics. "Newly observed data—now being correlated and calibrated with support from MPIfR—will soon add back the Large Millimetre Telescope in Mexico. This will bring an even sharper view of the jet‑launching region within reach", says Sebastiano von Fellenberg.

Source: Max Planck for Radio Astronomy/Press Releases

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Additional Information

The following scientists affiliated to the MPIfR are coauthors of this publication: Saurabh, Sebastiano D. von Fellenberg, Michael Janssen, Thomas P. Krichbaum, Dhanya G. Nair, Walter Alef, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, Silke Britzen, Gregory Desvignes, Sergio A. Dzib, Ralph P. Eatough, Christian M. Fromm, Ramesh Karuppusamy, Joana A. Kramer, Michael Kramer, Jun Liu, Andrei P. Lobanov, Ru-Sen Lu, Nicholas R. MacDonald, Nicola Marchili, Karl M. Menten, Cornelia Müller, Georgios Filippos Paraschos, Alexander Plavin, Eduardo Ros, Helge Rottmann, Alan L. Roy, Tuomas Savolainen, Lijing Shao, Pablo Torne, Efthalia Traianou, Jan Wagner, Robert Wharton, Gunther Witzel, Jompoj Wongphexhauxsorn, J. Anton Zensus, and Guang-Yao Zhao.

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Contacts:

Mr. Saurabh
Tel: +49 228 525-366
saurabh@mpifr-bonn.mpg.de
Max Planck Institute for Radio Astronomy, Bonn

Dr. Hendrick Müller
Tel: +1 626 781-0043
hmuller@nrao.edu
National Radio Astronomy Observatory (NRAO), USA

Dr. Sebastiano von Fellenberg
Tel: +1 437 328-5547
sfellenberg@utoronto.ca
Canadian Institute for Theoretical Astrophysics (CITA), University of Toronto, Canada

Dr. Nina Brinkmann
Press and Public Relations
Tel: +49 228 525-399
brinkmann@mpifr-bonn.mpg.de
Max Planck Institute for Radio Astronomy, Bonn

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Original publication

Saurabh et al.
Probing jet base emission of M87* with the 2021 Event Horizon Telescope observations
Astronomy & Astrophysics 705 (2026)
[doi.org/10.1051/0004-6361/202557022]

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Parallel Press Release

CITA Press Release
From the Canadian Institute for Theoretical Astrophysics

Saurabh/MPIfR

Animation (open in full screen)

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Images

• eht_closure_phase_triangles 1.56 MB


• m87_possible_jet_base 1.13 MB


• m87_possible_jet_base_blank 1.11 MB

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