ALMA Reveals Interstellar Comet 3I/ATLAS Formed in a Far Colder World Than Our Own

This artist’s impression compares the semi-heavy water content of the interstellar comet 3I/ATLAS (left) and Earth (right). Insets illustrate the relative abundance of deuterated water (HDO) molecules, showing that 3I/ATLAS contains over 30 times more HDO than is found in Earth’s oceans. This elevated ratio suggests the comet formed in an extremely cold environment, very different from the conditions that shaped our Solar System. Credit: NSF/AUI/NSF NRAO/M.Weiss

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First-ever measurement of deuterated water in an interstellar object shows its home system formed under extreme conditions

New observations from the Atacama Large Millimeter/submillimeter Array (ALMA) have yielded the first-ever measurement of deuterated water — also known as semi-heavy water — in an interstellar object. The discovery reveals that the interstellar comet 3I/ATLAS contains at least 30 times the proportion of semi-heavy water found in comets from our own Solar System, providing a direct chemical window into the frigid conditions under which its home star system formed.

The research was led by PhD student Luis E. Salazar Manzano at the University of Michigan, working with assistant professor Teresa Paneque-Carreño, who served as Principal Investigator of the ALMA Director's Discretionary Time program that made these observations possible. The data were obtained with ALMA's Atacama Compact Array (ACA) just six days after 3I/ATLAS reached its closest point to the Sun — a narrow observing window made possible by ALMA's unique ability to point toward the solar direction, unlike most optical telescopes.

"Our new observations show that the conditions that led to the formation of our Solar System are much different from how planetary systems evolved in different parts of our Galaxy," said Salazar Manzano.

Comets are often nicknamed dirty snowballs, in part because of their high water content — water that carries frozen chemical records of the environment in which they formed. Alongside ordinary water (H₂O), comets contain a molecular variant called deuterated water (HDO), in which one hydrogen atom is replaced by deuterium, a hydrogen atom with an extra neutron. In Solar System comets, roughly one molecule of semi-heavy water exists for every ten thousand molecules of ordinary water. In 3I/ATLAS, that ratio is at least 30 times higher — and over 40 times the proportion found in Earth's oceans.

Notably, ordinary water (H₂O) itself fell below ALMA's detection threshold during these observations. The team constrained the D/H ratio indirectly, by detecting HDO directly and inferring the water production rate through the excitation of methanol lines — a sophisticated modeling approach that showcases ALMA's unique analytical capabilities.

This elevated ratio points to an origin in an exceptionally cold and chemically distinct environment. "The chemical processes that lead to the enhancement of deuterated water are really sensitive to temperature and usually require environments colder than about 30 Kelvin, or about minus 406 degrees Fahrenheit," explained Salazar Manzano. The ratio was set as the comet's home system formed and has been preserved intact throughout its interstellar journey.

ALMA's instrumental role in this discovery was essential. Paneque-Carreño noted: "Most instruments can't point toward the Sun, but radio telescopes like ALMA can. We were able to observe the comet within days after perihelion, just as it peeked out from its transit behind the Sun. This gave us a constraint on these molecules that's not possible using other instruments."

Beyond being a chemical fingerprint of a distant planetary system, the HDO/H₂O ratio carries a special cosmological significance: the abundances of deuterium and hydrogen were set during the Big Bang itself, making this measurement a uniquely fundamental probe of the conditions under which other worlds are born. "Each interstellar comet brings a little bit of its history, its fossils, from elsewhere. We don't know exactly where, but with instruments like ALMA we can begin to understand the conditions of that place and compare them to our own," said Paneque-Carreño.

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

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Additional Information

This research is published in Nature Astronomy on April 24, 2026, under the title "A Direct View of the Chemical Properties of Water from Another Planetary System: Water D/H in 3I/ATLAS" by Salazar Manzano, Paneque-Carreño et al.

The original press release was issued by the National Radio Astronomy Observatory (NRAO), an ALMA partner on behalf of North America.

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

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

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Contacts:

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Seiichiro Naito
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New Curtin University-led research has used a radio telescope that spans the Earth to snap images that measure the immense power of jets from black holes, confirming scientists’ theories of how black holes help shape the structure of the Universe.

The strong stellar wind from the supergiant star pushes the jets launched by the black hole away from the star. This causes the jet direction to vary as the black hole and the supergiant star move around their orbit. Credit: ICRAR/Curtin University

The direction of the radio jet changes as the black hole and the star move around their orbit (shown in red).

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Dancing' Jets reveal immense power of Black Holes
Video Vimeo (link)

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In a paper published in Nature Astronomy, researchers found the power of the jets in Cygnus X-1 – a system comprised of the first confirmed black hole and a supergiant star – was equivalent to the power output of 10,000 Suns.

To record the measurement, researchers used an array of linked up telescopes separated by large distances to observe the black hole jets being buffeted by the winds of the star as the black hole moved around its orbit – much like how strong winds on Earth can push around water in a fountain.

By knowing the power of the wind and measuring how much the jets were bent, the researchers could determine the instantaneous power of the jets for the first time.

In addition, they were able to determine the speed of the black hole’s jets – about half the speed of light, or 150,000 km per second – another measurement that has challenged scientists for decades.

The research was led from the Curtin Institute of Radio Astronomy (CIRA) and the Curtin node of the International Centre for Radio Astronomy Research (ICRAR), in collaboration with the University of Oxford.

Lead author Dr Steve Prabu, who worked at CIRA at the time of the research and who is now based at the University of Oxford, said researchers were able to make the measurement using a sequence of images of the “dancing jets” – a term he used to describe the jets’ movement pattern as they were repeatedly deflected indifferent directions by the supergiant star’s powerful winds as the star and black hole moved around their orbits.

Dr Prabu said the measurement allowed scientists to understand what fraction of the energy released around black holes could be deposited into the surrounding environment, thereby changing the environment.

“A key finding from this research is that about 10 per cent of the energy released as matter falls in towards the black hole is carried away by the jets,” Dr Prabu said.

“This is what scientists usually assume in large-scale simulated models of the Universe, but it has been hard to confirm by observation until now.”

Co-author Professor James Miller-Jones, from CIRA and the Curtin node of ICRAR, said previous methodscould only measure the average jet power over thousands or even millions of years, preventing accurate comparisons with the X-ray energy released instantaneously from the infalling matter.

“And because our theories suggest that the physics around black holes is very similar, we can now use this measurement to anchor our understanding of jets, whether they are from black holes 10 or 10 million times the mass of the Sun,” Professor Miller-Jones said.

“With radio telescope projects such as the Square Kilometre Array Observatory currently under construction in Western Australia and South Africa, we expect to detect jets from black holes in millions of distant galaxies, and the anchor point provided by this new measurement will help calibrate their overall power output.

“Black hole jets provide an important source of feedback to the surrounding environment and are critical to understanding the evolution of galaxies.”

Other collaborating institutions included the University of Barcelona, the University of Wisconsin-Madison, the University of Lethbridge and the Institute of Space Science.

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

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A Possible GLIMPSE of the Universe’s First Stars

Illustration of a collection of Population III stars — the first stars in the universe — just 100 million years after the Big Bang. Credit: NOIRLab/NSF/AURA/J. da Silva/Spaceengine/M. Zamani; CC BY 4.0

Title: GLIMPSE: An Ultrafaint ≃10⁵ M_⊙ Pop III Galaxy Candidate and First Constraints on the Pop III UV Luminosity Function at z ≃ 6–7

Authors: Seiji Fujimoto et al.
First Author’s Institution: University of Toronto; The University of Texas at Austin
Status: Published in ApJ

You, me, your laptop, my $8 matcha, and just about everything else on Earth was forged in the fiery bellies of dying stars. Generations of stars had to live and die before the universe became enriched with any elements heavier than helium (what astronomers call “metals”). The first stars to undergo this cosmic cycle are known as Population III (Pop III) stars. Though their existence has been hypothesized since the 1960s, astronomers have failed to observe these distant metal-free stars or the faint, low-mass galaxies that host them.

The first Pop III stars likely formed around 100 million years after the Big Bang in pristine pockets of hydrogen gas. Although these are too distant for us to observe, we expect that as the universe started to become metal enriched, there were still existing pockets of gas introverted enough to survive unpolluted and form metal-free Pop III stars up to a redshift of z ~ 6–7 (when the universe was around 900 million years old)!

JWST is the perfect instrument to search for these systems. You can read other astrobites on the search for possible Pop III systems with JWST here and here. The authors of today’s article seek to develop the most efficient way of using JWST’s Near-Infrared Camera (NIRCam) to find the galaxies hosting Pop III stars. Using their selection method on existing NIRCam data, the authors identified one promising Pop III galaxy candidate.

Figure 1: Color–color diagram for selecting Pop III galaxies where the x and y-axes show the different NIRCam filters being subtracted. The cyan symbols are different Pop III models while the other colored dots are different metal-rich galaxy models. Adapted from Fujimoto et al. 2025

I’m Not Like Other Galaxies

In order to find a Pop III galaxy, we need to take a look at galaxies’ spectral energy distributions (SEDs). These are graphs that show the energy emitted by a galaxy at different wavelengths of light. Pop III galaxies are expected to have SEDs that differ from your everyday, metal-enriched galaxy. NIRCam will be especially sensitive to three key spectral features that show up in the SEDs of Pop III galaxies: an absent [O III] line (light emitted by doubly ionized oxygen atoms), a strong H-alpha line (light emitted when a hydrogen atom transitions from its third to its second energy level), and a significant Balmer jump (light absorbed to ionize electrons in the second energy level of a hydrogen atom). To identify these key SED characteristics, the authors use SED fitting and color–color diagrams to execute an efficient Pop III search with NIRCam.

The first selection method involves SED fitting. Astronomers create template SEDs that represent different types of galaxies and then compare these templates to the observed SEDs to see which one matches best. In this work, the authors use metal-rich galaxy templates and Pop III templates to fit the galaxies observed with NIRCam. They then calculate the chi-squared χ² (a statistical measure of best fit) between the data and all the SED templates. A galaxy is selected as a Pop III candidate if the Pop III model provides a good fit (χ² < 10) to the photometry and is significantly better than any metal-rich model. It’s kind of like looking for Cinderella by making every woman in the kingdom try on the glass slipper.

A color–color diagram plots the difference in magnitude between two filters on each axis. NIRCam filters are specially chosen to emphasize the SED characteristics above. When these filters are chosen, Pop III galaxies occupy a distinct region of this diagram as compared to metal-rich galaxies. For example, subtracting the F356W filter from the F277W filter is sensitive to the presence of the [O III] line and the Balmer jump. Figure 1 demonstrates how this color selection separates Pop III galaxies from typical galaxies.

Figure 2: SED of GLIMPSE-16043 with the best-fit Pop III template (blue) and best-fit metal-enriched template (gray). The top panel is the galaxy imaged in different filters from NIRCam and the Hubble Space Telescope. Credit: Fujimoto et al. 2025

O Pop III, Pop III, Wherefore Art Thou?

The authors apply their fresh new selection criteria to publicly available NIRCam data from large surveys. And (drum roll please) the slipper fits! The Pop III galaxy candidate GLIMPSE-16043 is an ultra-faint galaxy at z = 6.5. It was imaged in the GLIMPSE survey, which uses the technique of gravitational lensing to observe faint and distant galaxies.

The GLIMPSE survey targeted a massive galaxy cluster, Abell S1063. The cluster bends the light from distant galaxies and, like a giant lens, magnifies faraway objects, providing some of the deepest JWST imaging to date. The Pop III candidate passes both tests: it resides in the Pop III region of the color–color diagram, and its SED is best fit by a Pop III model, not a metal-rich galaxy model (see Figure 2). Next, spectroscopic follow-up is needed to ensure that this galaxy is truly metal free and not just extremely metal poor.

The authors conclude that our best shot at identifying additional Pop III galaxy candidates is using NIRCam to image large numbers of gravitationally lensed clusters. Without magnification from gravitational lensing, it may be impossible to see these ultra-faint Pop III galaxies. Once candidates have been identified, they can be followed up with deep spectroscopy to confirm their redshift and their lack of metals. Who knows? With these new methods, we may soon get a glimpse of the universe’s very first stars.

Original astrobite edited by Chris Layden and Margaret Verrico.

Source: American Astronomical Society/AAS-Nova

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About the author, Madison VanWyngarden:

I am a first-year PhD student in astronomy and NSF Graduate Research Fellow at the University of Arizona. I study galaxy formation and evolution in the distant universe and am particularly interested in dusty star-forming galaxies. In my free time, I love reading, hiking, and baking bread!

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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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Astronomers Determine Brown Dwarf Age Using Tiny Stellar Pulsations

An illustration of a star and a brown dwarf in a binary system.
Generated with ChatGPT by the University of Hawaiʻi .

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Results Test Brown Dwarf Theory challenging astrophysicists

Maunakea, Hawaiʻi – Astronomers using W. M. Keck Observatory on Maunakea, Hawaiʻi Island, have measured one of the most precise ages yet for a Sun-like star hosting a brown dwarf companion. The result offers a powerful new test of how brown dwarfs cool and evolve over time, helping to address a long-standing challenge in astrophysics.

The study focused on the nearby system HR 7672, which includes a Sun-like star and a faint brown dwarf companion. Using Keck Observatory’s Keck Planet Finder (KPF), the team detected subtle oscillations in the star’s surface, ripples that revealed its age to be 2.3 billion years.

Because the brown dwarf formed alongside the star, this precise stellar age serves as a benchmark for the companion’s evolution, offering a rare chance to directly test theoretical models of brown dwarf cooling.

“The 18% age uncertainty establishes the HR7672 system as a valuable benchmark for years to come,” said Yaguang Li, lead author and researcher at the University of Hawaiʻi at Mānoa.

The study, led by the University of Hawaiʻi Institute for Astronomy, is published in The Astrophysical Journal.

A Two-Decade Scientific Arc

The HR 7672 system has played a historic role in the study of substellar objects. The companion, known as HR 7672B, was first discovered by researcher Michael Liu, co-author and professor at the University of Hawaiʻi Institute for Astronomy. HR 7672B was the first directly imaged brown dwarfs orbiting a Sun-like star.

Using Keck Observatory’s Near-Infrared Camera (NIRC2) and the telescope’s Adaptive Optics system to correct for atmospheric blurring, Liu obtained a sharper image of the brown dwarf, which is 2,000 times fainter than its bright host star.

“Pioneering observations with Keck Observatory helped illuminate the so-called “brown dwarf desert,” the scarcity of such companions around Sun-like stars at close separations,” said Liu.

Now, more than two decades later, a new generation of Keck Observatory instrumentation continues to advance that legacy. Using ultra-precise measurements of the host star with the Keck Planet Finder (KPF) instrument, astronomers detected tiny stellar pulsations that reveal the star’s internal structure and age with unprecedented precision.

“The unique fast-readout mode of the Keck Planet Finder makes it the only instrument in the Northern Hemisphere capable of sampling oscillations on such short timescales,” added Li.

Testing How Brown Dwarfs Cool Over Time

Brown dwarfs are failed stars that are too small to sustain stable hydrogen fusion, so they gradually cool and fade as they age. Their brightness, therefore, depends sensitively on both their mass and age. However, astronomers have had difficulty testing theoretical models of this cooling, in part because reliable ages are rarely available.

Now, with this new and precise age measurement, combined with HR 7672B’s well-known luminosity and mass, the system becomes an exceptional “benchmark” for testing brown dwarf evolutionary models.

Comparing the observations with six different theoretical cooling models, the team found the best agreement with the most recent models that incorporate updated interior physics. Without the new data, the team would not have been able to distinguish this model from the five other possibilities.

These results demonstrate that high-precision stellar ages are essential for understanding substellar evolution — and show that precision spectroscopy with the next generation of observations will finally provide this information.

“Yaguang’s research has made this object even more valuable for our theoretical understanding of brown dwarfs,” said Liu.

As a next step, the researchers plan to generalize this method to a broader set of benchmark systems and test brown dwarf evolutionary models across different regimes.

Source: W. M. Keck Observatory/News

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Related Links
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• Science Paper.
• University of Hawaiʻi Release

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Media Contact:

Meagan O’Shea
moshea@keck.hawaii.edu

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Milky Way's 'little cousins' may hold clues about infant universe

(A) A dark matter map in our neighbourhood of the universe. The two large densities are dark matter halos of the Milky Way and Andromeda galaxy; (B) Zoomed-in on the dark matter map, showing a small dark matter clump ~700 million years after the Big Bang; (C-1 and C-2) stars and in the simulated ultra-faint dwarf galaxy, formed in the centre of the small dark matter halo in panel B. The two panels show two different radiation levels shortly after the Big Bang. It reveals how the ultra-faint dwarf galaxy changes its properties depending on which radiation is used. The scale on each image is in units of light years.Credit: J Sureda/A Fattahi/S Brown/S Avraham

Licence type: Attribution (CC BY 4.0)

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Ultra-faint dwarf galaxies – tiny satellite galaxies orbiting the Milky Way – have long been seen as cosmic fossils.

Now, a new study published today in Monthly Notices of the Royal Astronomical Society uses an unprecedented set of simulations to show just how powerfully these faint systems can reflect the conditions of the early universe and tell us why some galaxies grew and others did not.

They could also reveal what the universe's earliest 'climate' was like – for example, the level of radiation and how this impacted whether and where stars formed.

Dwarf galaxies are often described as small cousins of the Milky Way. They form in small dark matter halos which are predicted by the standard model of cosmology. The faintest examples of such systems are extreme in both size and fragility, and lie on the boundary of our knowledge about galaxy formation and dark matter.

"In this work we presented a brand-new suite of cosmological simulations focused on the faintest galaxies in the universe, with an unprecedented resolution.

"These are by far the largest sample of such galaxies ever simulated at these resolutions," said Associate Professor Dr Azadeh Fattahi, of the Oskar Klein Centre (OKC) in Stockholm, which led the new study with the LYRA collaboration, in collaboration with Durham University and the University of Hawaii.

"The smallest galaxiesare called ultra-faint dwarf galaxies, which are a million times less massive than the Milky Way or even smaller.

"Due to their small size these galaxies have proven very difficult to model and simulate."

This new simulation suite represents a major step forward, enabling a systematic view of how these galaxies form and evolve.

A down-to-earth analogy

"A useful analogy… is to plants and crops and how the way they grow is sensitive to the weather conditions," said Shaun Brown, who led the study while working at OKC and Durham University.

"In the same way that the yield of a crop in summer can indirectly tell you a lot about what the weather in spring must have been like, the properties of faint dwarf galaxies today can tell us a lot about the conditions, or weather, of the universe at a much earlier time."

What makes the results especially timely is that the simulations do more than reproduce faint dwarf galaxies – they suggest that these local objects can act as a probe of the universe's earliest 'climate'. The team explored how different assumptions about the early radiation environment influence which small dark matter haloes manage to form stars at all.

"In the paper we studied two different assumptions about the properties of the early universe when it was less than 500 million years old, to understand the effect on the properties of these small galaxies today when the universe is 13 billion years old," Brown explained.

"We found that these small ultra-faint galaxies are very sensitive to these changes, while more massive galaxies, like our Milky Way, don't really care," he added

"For the smallest galaxies, early conditions can decide whether they become visible galaxies – or remain starless dark matter halos."

Future research

That sensitivity opens a clear path to testing early-universe physics with upcoming observations.

"Excitingly, in the near future we will have data from the Vera C. Rubin Observatory which will be able to find many more of these ultra faint dwarfs around the Milky Way," Dr Fattahi said.

Many astronomers hope Rubin can deliver a near-complete census of Milky Way satellite galaxies – and these simulations hint that this census may carry information far beyond our local neighbourhood.

"Our work suggests that these upcoming observations of the very local universe will be able to constrain what the universe at its infancy looked like, something we currently cannot directly access with other observations," Dr Fattahi added.

The result is particularly relevant in the light of recent discoveries, by the James Webb Space Telescope (JWST), of galaxies in the early universe, some of which are unexpectedly massive and bright.

If the early universe is producing surprises at large distances, then local relics from the same epoch – ultra-faint dwarfs – may provide an additional route to understanding what happened, according to Dr Fattahi.

But with research such as this there are still major practical challenges to overcome.

"Running these simulations is challenging, and extremely expensive in both time and computational resources. In total it took more than 6 months to run all of the simulations," Dr Fattahi added.

"The simulation also produces very large amounts of data (in total ~ 300 terabytes). Thismeant many of the old algorithms designed for smaller amounts of data needed updating and improving to effectively handle this new large amount of data."

Most of the work was carried out on the COSMA 8 supercomputer, which is designed for simulation-driven research. Durham University’s Institute for Computational Cosmology hosts COSMA 8 on behalf of the UK’s DiRAC High Performance Computing Facility.

Looking ahead, Dr Fattahi’s team plans to use the new suite to tackle questions that are still open in modern galaxy and structure formation, such as where can we find the very first generation of stars formed in the universe? Or what do the properties of ultra-faint dwarf galaxies tell us about the nature of dark matter?

Source: Royal Astronomical Society (RAS)/News and Press

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Media contacts:

Sam Tonkin
Royal Astronomical Society
Mob: +44 (0)7802 877 700
press@ras.ac.uk

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Science contacts:

Dr Azadeh Fattahi
Oskar Klein Centre
azadeh.fattahi@fysik.su.se

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Images & captions

Dwarf galaxies

Caption: (A) A dark matter map in our neighbourhood of the universe. The two large densities are dark matter halos of the Milky Way and Andromeda galaxy; (B) Zoomed-in on the dark matter map, showing a small darkmatter clump ~700 million years after the Big Bang; (C-1 and C-2) stars and gas in the simulated ultra-faint dwarf galaxy, formed in the centre of the small dark matter halo in panel B. The two panels show twodifferent radiation levels shortly after the Big Bang. It reveals how the ultra-faint dwarf galaxy changes its properties depending on which radiation is used. The scale on each image is in units of light years.

Credit: J Sureda/A Fattahi/S Brown/S Avraham

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Further information

The paper ‘LYRA ultra-faints: The emergence of faint dwarf galaxies in the presence of an early Lyman-Werner background’ by Brown et al. has been published in Monthly Notices of the Royal Astronomical Society. DOI: 10.1093/mnras/stag439.

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Notes for editors

About the Royal Astronomical Society

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.

The RAS organises scientific meetings, publishes international research journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

The RAS accepts papers for its journals based on the principle of successful peer review, following which experts on the Editorial Boards accept the papers for publication. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.

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Keep up with the RAS on Instagram, Bluesky, LinkedIn, Facebook and YouTube.

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Submitted by Sam Tonkin on Fri, 24/04/2026 - 00:01

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Astronomers find an exo-Jupiter, and it seems to have clouds

Artist's impression of the planet Epsilon Indi Ab, with water clouds atop its ammonia-dominated atmosphere.
© E. C. Matthews, MPIA / T. Müller, HdA. Download image

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To the point

• New observations: Astronomers have used the James Webb Space Telescope to study the atmosphere of a massive Jupiter-analogue.


• Evidence for clouds: Surprisingly, the observations indicate the presence of water-ice clouds – previous models had been too simple!


• Part of a larger search: Observations and analysis provide a test run for certain challenges of observing a “second Earth”

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A team of astronomers led by Elisabeth Matthews at the Max Planck Institute for Astronomy (MPIA) has made a discovery that highlights the limits of most current models of exoplanet atmospheres: water-ice clouds on a distant Jupiter-like exoplanet called Epsilon Indi Ab. The way the observations were made has broader implications for exoplanet research: as an interesting immediate step on the path towards eventually finding and characterizing an Earth-analogue exoplanet.

Step by step towards a second Earth

Exoplanet research has an ambitious long-term goal: at some time within the next few decades, astronomers hope to be able to detect traces of life on an exoplanet. On the path towards that goal, exoplanet research has gone through several stages. In the first stage of research, from 1995 to about 2022, the main focus of exoplanet researchers was on detecting more and more exoplanets, using indirect methods that gave them information about the masses of some exoplanets, the diameters of others, and in some cases both mass and diameter.

When the James Webb Space Telescope (JWST) began operating in earnest in 2022, exoplanet research entered a second stage: High-quality, detailed information about the atmospheres of many exoplanets became available for a considerable number of planets, and researchers began to reconstruct the properties of such atmospheres in some detail. This is still at least one stage removed from realistic searches for life on exoplanets, which are expected to require the next generation of space telescopes.

With the new study, the astronomers are exploring some aspects of these next-level methods – although not yet for a planet like Earth. Elisabeth Matthews (Max Planck Institute for Astronomy), the study’s lead author, says: “JWST is finally allowing us to study solar-system analogue planets in detail. If we were aliens, several light years away, and looking back at the Sun, JWST is the first telescope that would allow us to study Jupiter in detail. For studying Earth in detail, we would need much more advanced telescopes, though.”

Elusive exo-Jupiters But as amazing as results from JWST about exoplanet atmospheres are, studying the analogues of our Solar System’s Jupiter has proven surprisingly difficult. Almost all gas giants studied with JWST so far differ from Jupiter in that they are much, much hotter – for the most common method of studying exoplanet atmospheres to work, the planet needs to pass in front of its host star from the perspective of an observer on Earth, and the probability for that configuration is much higher when the planet is closer to its star, which in turns makes the planet comparatively hot. The new study by Elisabeth Matthews and her colleagues uses a different technique. This is the closest observers have come to studying a Jupiter-analogue – and it has provided at least one surprise!

Matthews and her colleagues used JWST’s mid-infrared instrument MIRI to obtain direct images of the planet Epsilon Indi Ab. Naming conventions for exoplanets are such that this designation indicates the first planet discovered to orbit the star Epsilon Indi A in the constellation Indus (in the southern sky). Bhavesh Rajpoot, a PhD student at the Max Planck Institute for Astronomy who contributed to the study, says: “This planet has a considerably greater mass than Jupiter – the new study fixes its mass at 7.6 Jupiter masses – but the diameter is about the same as for its solar-system cousin.”

A more massive, slightly warmer Jupiter

Epsilon Indi Ab is about four times as distant from its central star as Jupiter is from the Sun. The star Epsilon Indi A itself is a bit less massive and a bit less hot than our Sun. This makes the surface temperature of Epsilon Indi Ab very low, at about 200 to 300 Kelvin (between –70 and +20 degrees Celsius). The reason the planet is slightly warmer than Jupiter (140 K) is that there is still a lot of heat remaining from the planet formation phase. Over the next billions of years, Epsilon Indi Ab will steadily cool down, eventually becoming colder than Jupiter. The astronomers used the coronagraph of the MIRI instrument to block out the central star’s light, which would otherwise outshine the planet’s much dimmer light. They then took an image through a very particular filter: 11.3 μm, which is just outside the wavelength region close to 10.6 μm that is characteristic for ammonia molecules NH3. The comparison with images at 10.6 μm that Matthews and her team had already taken in 2024 enabled the astronomers to estimate the amount of ammonia present. (Incidentally, both the mechanical filter wheels placing the coronagraph and the filter in front of the MIRI camera were constructed at MPIA, one of the German contributions to the JWST.)

Surprising evidence for clouds

For Jupiter, both ammonia gas and ammonia clouds dominate the upper layers of the atmosphere that are visible in observations. Given its properties, Epsilon Indi Ab was thought to have massive amounts of ammonia gas as well, although not ammonia clouds. Surprisingly, the photometric comparison showed somewhat less ammonia than expected. The best explanation Matthews and her colleagues found for this deficit was the presence of thick but patchy water-ice clouds, similar to the high-altitude cirrus clouds in Earth’s atmosphere – an unexpected complication!

In interpreting observations of this kind, astronomers compare their data to simulations of planetary atmospheres. But most of the published models neglect to include clouds, as the presence of clouds makes the computation that much more complicated – clearly something theorists will need to fix! James Mang (University of Texas at Austin), a co-author of the study, says: “It’s a great problem to have, and it speaks to the immense progress we’re making thanks to JWST. What once seemed impossible to detect is now within reach, allowing us to probe the structure of these atmospheres, including the presence of clouds. This reveals new layers of complexity that our models are now beginning to capture, and opens the door to even more detailed characterization of these cold, distant worlds.”

An opportunity for the Roman Space Telescope

On the upside, there is an upcoming opportunity for observing the water-ice clouds, which are very reflective directly: NASA’s Nancy Grace Roman Space Telescope, where MPIA is a partner, is slated for launch in 2026–2027, and should be suitable for exactly that kind of observation. In the meantime, Matthews and her colleagues are applying for JWST observation time to target additional cold Jupiter-analogues. And at the same time that Matthews and other astronomers are learning more about cold exo-Jupiters, their observational techniques are laying the groundwork that, if all goes well, will help future observers target earthlike planets, in search of life.

Background information

The results described here have been published as E. C. Matthews et al., “A second visit to Eps Ind Ab with JWST: new photometry confirms ammonia and suggests thick clouds in the exoplanet atmosphere of the closest super-Jupiter” in the Astrophysical Journal Letters.

The MPIA researchers involved are Elisabeth Matthews and Bhavesh Rajpoot, in collaboration with James Mang and Caroline Morley (University of Texas at Austin), Aarynn Carter and Mathilde Mâlin (Space Telescope Science Institute), and others.

Source: Max Planck Institute for Astronomy/News

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Contacts:

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

Dr. Elisabeth Matthews
Tel: +49 6221 528-102
matthews@mpia.de
Max Planck Institute for Astronomy, Heidelberg

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Original publication

Elisabeth C. Matthews, James Mang, Aarynn L. Carter, Mathlide Mâlin, Caroline V. Morley, Bhavesh Rajpoot, Leindert A. Boogaard, Jennifer A. Burt, Ian J. M. Crossfield, Fabo Feng, Anne-Marie Lagrange, Mark W Phillips
A second visit to Eps Ind Ab with JWST: new photometry confirms ammonia and suggests thick clouds in the exoplanet atmosphere of the closest super-Jupiter

Astrophysical Journal Letters (2026)

Source | DOI

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Euclid Space Warps: help spot galaxies bending spacetime

Strong gravitational lenses captured by Euclid

A collage of fourteen by eight squares containing examples of gravitational lenses. Each example typically comprises a bright centre with smears of stacredirs in an arc or multiple arcs around it as a result of light travelling towards Euclid from distant galaxies being bent and distorted by normal and dark matter in the foreground. In some rare cases the smearing is in a complete ring, crea,brting a so-called Einstein Ring. Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by M. Walmsley, M. Huertas-Company, J.-C. Cuillandre.Hi-res JPG

Licence: CC BY-SA 3.0 IGO or ESA Standard Licence (content can be used under either licence)

Infographic explaining how an Einstein Ring is formed

Against a dark blue background, this infographic contains a paragraph of text in the top left corner, the logo of ESA in the top right corner and a succession of graphics in the bottom half of the image. The text paragraph explains the principle behind Einstein rings, and it can be read in the image caption. The graphics below it illustrate this astrophysical phenomenon, and by looking at them from left to right we can understand the process of how Einstein rings are formed.

The left-most element in the bottom half of the image is a graphic representation of a galaxy, labelled ‘distant galaxy’. To the right of it, another galaxy is shown, labelled ‘Foreground galaxy acting as a magnifying lens’. The third illustration, to the right of the previous one, shows ESA’s Euclid space telescope and is labelled ‘Telescope’. The ‘distant galaxy’ and the ‘Telescope’ are connected by two lines that form an elongated diamond-shape around the ‘Foreground galaxy’. This line is labelled ‘Gravity bends the light rays of the distant galaxy’. The fourth and last illustration in the line shows a ring of light around a central disk and is labelled ‘What the telescope sees’. Credit: ESA. Hi-res JPG

Licence: CC BY-SA 3.0 IGO or ESA Standard Licence (content can be used under either licence)

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In brief

With the launch of Space Warps, a new citizen science project on the Zooniverse platform, you can now join in the search to find rare and elusive strong gravitational lenses in never-before-seen images captured by the European Space Agency’s Euclid space telescope. The project aims at shining a light on dark matter in galaxies and providing clues about mysterious dark energy.

In-depth

Warps in spacetime do not only show up in science fiction movies like Interstellar. In real life, we can see the warping effect that gravity has on spacetime in the form of gravitational lensing.

The enormous gravity of a massive object – such as a galaxy or cluster of galaxies – distorts the shape of spacetime and can bend the light rays coming from a distant galaxy behind. By warping spacetime, the foreground galaxy acts like a magnifying glass.

Light from the background object that would be obscured doesn’t travel in a straight line anymore. Instead, it curves around the intervening mass, often producing multiple images, stretched arcs, or even a complete ring known as ‘Einstein ring’, like the one recently discovered by Euclid.

Strong gravitational lenses offer a striking demonstration of Einstein’s theory of general relativity, showing that matter in the Universe can act as a natural telescope, bringing distant objects into sight.

ESA’s Euclid telescope is revolutionising the studies of strong gravitational lensing by providing very sensitive imaging over large swaths of the sky in unprecedented detail. This is exactly what is needed to identify rare gravitational lenses.

In March 2025, 500 galaxy-galaxy strong lenses were found nestled in just the first 0.04% of Euclid data, most of them previously unknown. This pioneering catalogue was created thanks to the combined effort from citizen scientists, artificial intelligence (AI) and researchers.

Early glimpse of new Euclid images

As Euclid continues its survey, sending around 100 GB of data back to Earth every day, ESA and the Euclid Consortium once again need help from citizen scientists to identify strong gravitational lenses in a large data set.

For this, the Space Warps team has launched a citizen science project based on new Euclid images, which will be part of the future Euclid Data Release 1. While this data is not public yet, by participating in this new citizen science project you can get an early glimpse of these new images of galaxies captured by the telescope.

For this project, you will be inspecting new high quality imaging data from Euclid in which many previously unknown strong lenses are hiding. About 300 000 images pre-selected by AI algorithms will be shown, which are fine-tuned with the results from the initial citizen-science Euclid strong lens search. These are the highest ranked candidates from a whopping 72 million galaxies from DR1 that were classified by the AI algorithms. Scientists expect that this exquisite high-quality data will reveal more than 10 000 new lenses.

What can we learn from strong lenses.

The Euclid mission explores how the Universe has expanded and how its structure has changed through cosmic history using mainly two methods: weak lensing and baryonic acoustic oscillations. From this, scientists can learn more about the role of gravity and the nature of dark matter and dark energy.

Strong gravitational lenses can also provide insights into these central questions. For example, strong lensing features can ‘weigh’ individual galaxies and clusters of galaxies. This reveals the total matter (whether dark or light) and traces the distribution of dark matter. By studying strong lenses across cosmic time, scientists can trace the expansion of the Universe and its apparent acceleration. This will provide additional insight into the role of dark energy..

“We’ve already seen the success of combining AI with visual inspection by citizen volunteers and scientists on Space Warps, efficiently finding hundreds of high‑probability lens candidates in an initial small Euclid search in 2024”, explains Aprajita Verma, Space Warps’ co-founder and project lead at the University of Oxford, UK..

“In this brand new DR1 data, 30 times larger than the initial search and together with our improved AI algorithms, we are expecting to find more than 10 000 high quality lens candidates. This is more than four times the number of lenses than we have been able to find since the first gravitational lens was discovered nearly 50 years ago.”.

This step-change is possible thanks to Euclid. The mission can map large areas of the sky with unique sharpness, an ideal combination for finding rare objects like strong gravitational lenses..

“We can’t wait to see what we will find within this unprecedented dataset. Join us on Space Warps to take part in this exciting search!” concludes Aprajita.

Euclid: ESA’s mission into the unknown
Access the video

Source: ESA/Science Exploration

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About Euclid

Euclid was launched in July 2023 and started its routine science observations on 14 February 2024. The goal of the mission is to reveal the hidden influence of dark matter and dark energy on the visible Universe. Over a period of six years, Euclid will observe the shapes, distances and motions of billions of galaxies out to 10 billion light-years. Euclid is a European mission, built and operated by ESA, with contributions from NASA. The Euclid Consortium – consisting of more than 2000 scientist from 300 institutes in 15 European countries, the USA, Canada, and Japan – is responsible for providing the scientific instruments and scientific data analysis. ESA selected Thales Alenia Space as prime contractor for the construction of the satellite and its service module, with Airbus Defence and Space chosen to develop the payload module, including the telescope. NASA provided the detectors of the Near-Infrared Spectrometer and Photometer, NISP. Euclid is a medium-class mission in ESA’s Cosmic Vision Programme.

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NASA’s Hubble Dazzles With Young Stars in Trifid Nebula

Trifid Nebula (Wide Field Camera 3 Image)

NASA celebrates Hubble’s 36th anniversary with a new image of the Trifid Nebula, a star-forming region it first captured in 1997. The telescope leveraged almost its full operational lifetime to show us changes in the nebula on human time scales with an improved camera. Credit Image: NASA, ESA, STScI; Image Processing: Joseph DePasquale (STScI)

Full Trifid Nebula (Rubin Image with Hubble Close-up)

A pullout shows where the Hubble Space Telescope’s close-up image is located within the wider Trifid Nebula. The image at left was taken by the NSF-DOE Vera C. Rubin Observatory in Chile. The color assignments in the images vary based on the filters in the telescopes’ cameras. Credit Image: Rubin Observatory, NASA, ESA, STScI

Trifid Nebula (WFC3 Compass Image)

This closeup image of the Trifid Nebula (Messier 20 or M20) captured by NASA's Hubble Space Telescope’s Wide Field Camera 3 (WFC3) shows compass arrows, scale bar, and color key for reference. Credit Image: NASA, ESA, STScI; Image Processing: Joseph DePasquale (STScI)

Video: Changes in the Trifid Nebula (1997 and 2026 Observations)

Compare Hubble’s two observations of a portion of the Trifid Nebula, one taken in 2026 with the telescope’s current Wide Field Camera 3 and the other in 1997 with an earlier instrument (the Wide Field and Planetary Camera 2). Credit Video: NASA, ESA, STScI, Leah Hustak (STScI), Christian Nieves (STScI); Image Processing: Joseph DePasquale (STScI), Alyssa Pagan (STScI); Contributor: Subaru Telescope, Robert Gendler; Acknowledgment: Gregory Bacon (STScI), James Muzerolle (STScI), Frank Summers (STScI)

Article: New Hubble Image Reveals Details in the Heart of the Trifid Nebula

This June 2004 release of Hubble images provided astronomers with detailed views of structures at the heart of the Trifid Nebula.

The Trifid Nebula, Stellar Nursery Torn Apart by Radiation from Nearby Star

Tris Hubble image, taken in 1997, revealed a stellar jet protruding from the head of a dense cloud.Credit: NASA and Jeff Hester (Arizona State University

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This shimmering region of star-formation, a close-up of the Trifid Nebula about 5,000 light-years from Earth, was captured in intricate detail by NASA’s Hubble Space Telescope. The colors in Hubble’s visible light image, which marks the 36th anniversary of the mission's launch on April 24, are reminiscent of an underwater scene filled with fine-grained sediments fluttering through the ocean’s depths.

Several massive stars, which are outside this field of view, have shaped this region for at least 300,000 years. (See them in a wider view.) Their powerful winds continue to blow an enormous bubble, a small portion of which is shown here, that pushes and compresses the cloud’s gas and dust, triggering new waves of star formation.

This isn’t the first time Hubble has gazed at this scene. The telescope observed the Trifid in 1997 and now, 29 years later, it has leveraged almost its full operational lifetime to show us changes in the nebula on human time scales. Why look at the same location again? In addition to seeing changes over time, Hubble is also equipped with an improved camera with a wider field of view and greater sensitivity that was installed during Servicing Mission 4.

Star formation in ‘Cosmic Sea Lemon’

Hubble’s view of the Trifid Nebula (also known as Messier 20 or M20) focuses on a “head” and undulating “body” of a rusty-colored cloud of gas and dust that resembles a marine sea lemon, or sea slug, that appears as if it is gliding through the cosmos.

The Cosmic Sea Lemon’s left “horn” is part of Herbig-Haro 399, a jet of plasma periodically ejected over centuries by a young protostar embedded in the head of the sea lemon. Changes, as seen in the video below, allow researchers to measure the speeds of the outflows and determine how much energy the protostar is injecting into these regions. These measurements will provide insights into how newly formed stars interact with their surroundings.

To the immediate lower right is evidence of the counter jet: jagged orange and red lines that ”run” down the back of the sea lemon’s neck, where a natural V appears in the brown dust.

The darker, more triangular “horn” on the right of the “head” hosts another young star at its tip. Zoom in to see a faint red dot with a tiny jet. The green arc above it may be evidence that a circumstellar disk is being eroded by the intense ultraviolet light from nearby massive stars. The clearer area around this protostar suggests it may almost be finished forming.

To the immediate left of the Cosmic Sea Lemon is a small, faint pillar that resembles a water bear. Much of this pillar’s gas and dust has been blown away, but the densest material at the top persists.

Streaks and sharp lines offer more clues about other young stars’ activities. Spy an example by looking near the center for a rippling angled line that begins in a bright orange and ends in a blazing red. In the image comparison, it appears to move, which means it may be a jet shot out by another actively forming star buried deeply in dust.

NASA is celebrating the 36th anniversary of the Hubble Space Telescope with a stunning new look at the Trifid Nebula, a star-forming region about 5,000 light-years away. Powerful ultraviolet light from massive stars carved out this glowing bubble, triggering new waves of star birth. Sit back and relax as Hubble Senior Project Scientist, Dr. Jennifer Wiseman takes us on a tour of this beautiful image. Credit: NASA; Lead Producer: Paul Morris. Video YouTube

Prismatic ‘sea’ of color

In Hubble’s visible light observations, the clearest view is toward the top left, where it’s bluer. Strong ultraviolet light from massive stars, not in the field of view, stripped electrons from nearby gas, creating a glow, with winds sculpting a bubble by clearing out surrounding dust.

At the top of the Cosmic Sea Lemon’s head, bright yellow gas streams upward. This is an example of ultraviolet light plowing into the dark brown dust, stripping and dismantling the gas and dust.
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Many ridges and slopes of dark brown material will remain for a few million years, as the stars’ ultraviolet light slowly eats away at the gas. The densest areas are home to protostars, which are obscured in visible light.

The far-right corner is nearly pitch black. This is where the dust is the densest. The stars that appear here may not be part of this star-forming region — they might be closer to us, in the foreground.

Now, scan the scene for bright orange orbs. These stars have fully formed, clearing the space around them. Over millions of years, the nebula’s gas and dust will disappear — only stars will remain.

Unprecedented longevity, nonstop discoveries

Hubble’s varied instruments and the expansive range of light it collects — from ultraviolet through visible to near-infrared — have helped researchers make ground-breaking discoveries for decades and supply new data daily that will inevitably lead to more.

The telescope has taken over 1.7 million observations to date. Almost 29,000 astronomers have published peer-reviewed science papers using Hubble data collected over the telescope’s 36-year lifetime, resulting in more than 23,000 publications, with almost 1,100 in 2025 alone. Hubble’s observational data is publicly available in the Barbara A. Mikulski Archive for Space Telescopes at the Space Telescope Science Institute in Baltimore, while its mission descriptions, history, and gallery of popular images are found on NASA’s Hubble website.

Since 2022, researchers have regularly combined Hubble’s observations with those from NASA's James Webb Space Telescope to push opportunities for discovery further. Very soon, astronomers will begin diving into huge near-infrared datasets from vast surveys from NASA's new Nancy Grace Roman Space Telescope, and will seek to compare them to existing or new Hubble observations to clarify what is at work. For context, Roman’s camera can cover the entire Trifid Nebula, showing the full bubble, with a single pointing — and may turn up interesting objects for follow-up.

Another flagship to look forward to? The mission concept known as the Habitable Worlds Observatory, which would have a significantly larger mirror than Hubble — leading to higher resolution images — and, like Hubble, capture ultraviolet, visible, and infrared light. This next-generation space telescope would advance science across all of astrophysics, and would be the first specifically engineered telescope to identify habitable, Earth-like planets next to relatively bright stars like our Sun and examine them for evidence of life.

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.

Source: NASA's Hubble Space Telescope/News

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Details:

Last Updated: Apr 20, 2026
Editor: Andrea Gianopoulos
Location: NASA Goddard Space Flight Center

Contact Media:

Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov

Claire Blome, Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland

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Collaboration led by the German Center for Astrophysics (DZA) joins the ZTF partnership

ZTF image of the Orion nebula
Credit: Caltech Optical Observatories

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April 16, 2026 // A collaboration consisting of the German Center for Astrophysics in Goerlitz, the Leibniz-Institute for Astrophysics (AIP), Potsdam and the German Electron Synchrotron DESY is officially joining the Zwicky Transient Facility (ZTF) partnership, expanding our scientific collaborative network in Europe and growing the team of world-class researchers and students.

The Zwicky Transient Facility (ZTF) is designed to scan the night sky rapidly and repeatedly to detect transient astronomical events — things that change or appear suddenly, like supernovae, variable stars, asteroids, and other cosmic phenomena. It operates at the Palomar Observatory in California, using a wide-field camera mounted on the Samuel Oschin Telescope. ZTF helps astronomers catch time variable events in the universe in near real-time, enabling quick follow-up observations and advancing our understanding of dynamic cosmic processes.

“This is exciting news. DZA is quickly attracting exceptional talent from around the world and developing cutting-edge scientific and research infrastructure. I am convinced we will build a solid and long-term partnership that will benefit astrophysics both in the USA and Europe”, says Mansi Kasliwal, a professor of astronomy at Caltech and the principal investigator of ZTF.

The German Center for Astrophysics, currently under construction, is envisioned as a new hub for scientific innovation in Lusatia, a growing region in Eastern Germany. The center aims to become a global leader in developing cutting-edge and sustainable infrastructure for scientific research in astrophysics with an initial focus on radio and multi-messenger astronomy.

Prof. Stefan Wagner from the University of Heidelberg and DZA, Prof. Matthias Steinmetz from the Leibniz Institute for Astrophysics Potsdam (AIP), and Prof. Samaya Nissanke, lead scientist at DESY who is also a long-standing collaborator with members of the ZTF multi-messenger science group, are heading different research areas in DZA and have joined ZTF as co-investigators.

“After working closely with ZTF colleagues since 2009, in the early days of its precursor the Palomar Transient Factory, I am thrilled to be joining ZTF as an official partner. ZTF has been extraordinary across a wide range of discoveries and has quite literally led the way in the optical follow up of gravitational wave mergers over the past seven years,” says Samaya Nissanke, whose research focus is on studying black holes and neutron star mergers with gravitational waves.

”With ZTF and our well established collaboration with DZA, AIP can now expand its portfolio mainly focussed on spectroscopic surveys with a new dimension - time domain astrophysics,” adds Matthias Steinmetz of AIP.

Stefan Wagner is also interested in employing big data methods and technology to advance survey science. As partners in ZTF, he and Matthias Steinmetz will lead the transfer of the real-time pipeline from Caltech IPAC to Germany, employing the computational facilities at the TUD University of Dresden.

“Exploring the dynamic universe currently requires constant innovations in data science to enable astronomers to analyze large data streams from multiple telescopes quickly. I am looking forward to working with our colleagues at DZA to provide excellent survey data from ZTF to the astronomical community around the world”, says Matthew Graham, a co-PI of ZTF.

The DZA led collaboration is joining ZTF as a major partner with full access to ZTF's proprietary partnership data.

Source: Leibniz Institute for Astrophysics Potsdam (AIP)/News

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Media contact:

Tilo Bergemann
Phone: +49 331 7499 803
presse@aip.de

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Further information

www.deutscheszentrumastrophysik.de

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The Leibniz Institute for Astrophysics Potsdam (AIP) is dedicated to astrophysical questions ranging from the study of our sun to the evolution of the cosmos. The key areas of research focus on stellar, solar and exoplanetary physics as well as extragalactic astrophysics. A considerable part of the institute's efforts aims at the development of research technology in the fields of spectroscopy, robotic telescopes, and e-science. The AIP is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory of Potsdam founded in 1874. The latter was the world’s first observatory to emphasize explicitly the research area of astrophysics. The AIP has been a member of the Leibniz Association since 1992.

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NASA Finds Young Stars Dim in X-rays Surprisingly Quickly

Trumpler 3, NGC 2353, and NGC 2301
Credit: X-ray: NASA/CXC/Penn State Univ/K. Getman; Optical/IR: PanSTARRS;
Image Processing: NASA/CXC/SAO/N. Wolk

JPEG (390.4 kb) - Large JPEG (7 MB) - Tiff (97 MB) - More Images

A Tour of NASA Finds Young Stars Dim in X-rays Surprisingly Quickly - More Videos

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• A new study using NASA’s Chandra X-ray Observatory has young Sun-like stars are dimming more significantly than previously thought.


• This result has a parallel to the new ‘Project Hail Mary’ book and movie, though there are obvious clear differences.


• The causes of the dimming in the Chandra study are completely natural, arising from the magnetic fields inside the stars are less efficient.


• In fact, this quieting of these younger cousins to the Sun likely boosts the prospects of life on any planets orbiting these stars.

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These images of star clusters represent a new study from NASA’s Chandra X-ray Observatory that shows how young Sun-like stars are dimmer in X-rays than previously thought. As described in our latest press release, this result has implications for the prospects of life developing and surviving on planets in orbit around these stars.

Trumpler 3 and NGC 2353 are so-called open clusters that contains hundreds of young stars. These stars are tied to each other through gravity, having been formed from the same clouds of gas. Many of these stars have masses that are similar to our Sun, but are much younger. In these new composite images of Trumpler 3 and NGC 2353, X-rays from Chandra (purple) have been combined with an optical image from the PanSTARRS telescope in Hawaii (red, green, and blue). Another star clusters from the new Chandra study, NGC 2301 is shown in the same color schemes with the X-ray and optical data.

In total, the new Chandra study looked at eight clusters of stars between the ages of 45 million and 750 million years old. (By comparison, our Sun has lived for about 4.6 billion years.) The researchers found that Sun-like stars older than about 100 million years in these clusters unleashed only about a quarter to a third of the X-rays that they expected.

This relative calm could be a boon to the formation of life on planets around stars that are younger versions of our own Sun. This is because large amounts of X-rays can erode a planet’s atmosphere and prevent formation of molecules necessary for organic life, as we know it. On average, three-million-year-old stars with a mass equal to the Sun produce about a thousand times more X-rays than today's Sun. Meanwhile, 100-million-year-old solar-mass stars are about 40 times brighter in X-rays than the present Sun.

An artist’s illustration depicts X-rays and other high energy radiation from a young Sun-like star eroding some of the atmosphere of an orbiting planet. Lower levels of X-rays will cause less erosion of planetary atmospheres.

Illustration of a young Sun-like star eroding some of the atmosphere of an orbiting planet.
Credit: NASA/SAO/CXC/M. Weiss

The researchers found that stars with about the same mass as the Sun quieted down relatively rapidly — after a few hundred million years — while ones with less mass kept up their high levels of X-ray emission for longer. Combined with a decrease in the energy of the X-rays and the disappearance of energetic particles, the Sun-sized stars are apparently better suited to host planets with robust atmospheres and possibly blossoming life than previously thought.

The team used data from ESA’s Gaia satellite and X-ray data from the ROSAT mission. This data allowed them to identify the stars that were members of the clusters (not foreground or background stars). To measure the X-ray output from the stars, they made new Chandra observations of five clusters with ages between 45 million and 100 million years and Chandra and ROSAT data from archives to study three older clusters with ages between 220 and 750 million years.

A new paper describing these results has been accepted and appears in The Astrophysical Journal. The authors of the paper are Konstantin Getman (Penn State University), Eric Feigelson (Penn State), Vladimir Airapetian (NASA Goddard Space Flight Center), and Gordon Garmire (Penn State).

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 Finds Young Stars Dim in X-rays Surprisingly Quickly

Source: NASA’s Chandra X-ray Observatory

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Visual Description:

This release features three composite images and one artist's illustration. Each composite image depicts a different star cluster packed with countless glowing specks of light. The close-up artist's illustration depicts the effects of a young Sun-like star's high energy radiation on the atmosphere of an orbiting planet.

The three clusters depicted in today's release are Trumpler 3, NGC 2353, and NGC 2301. In each image, the blackness of space is blanketed in white, blue, orange, purple, and golden yellow dots. Some of the dots are in the foreground, while others are background stars. Many in the middle-ground are clustered Sun-like stars being observed in a new study by Chandra. Some of the stars in the cluster and foreground appear as gleaming dots with glowing halos and occasional diffraction spikes, while the background stars are generally smaller and fainter.

In these composite images, purple represents X-rays from Chandra, while reds, greens and blues are courtesy of optical images from the Pan-STARRS telescope in Hawaii.

Results from the new study reveal that many young Sun-like stars are dimmer in X-rays than previously thought. X-rays and other high energy radiation from a young Sun-like star can erode some of the atmosphere of an orbiting planet. This erosion is highlighted in the artist's illustration. Here, a massive ball of churning fire, the young Sun-like star, occupies our left half of the photorealistic graphic. At its right is an orbiting planet, a relatively small, pale sphere, shedding its atmosphere, depicted as a wake of faint blue mist.

Sun-like stars that emit lower levels of X-rays will cause less atmospheric erosion on orbiting planets. This impacts the prospects of life developing and surviving on planets orbiting these stars.

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Fast Facts for Trumpler 3:

Credit: X-ray: NASA/CXC/Penn State Univ/K. Getman; Optical/IR: PanSTARRS; Image Processing: NASA/CXC/SAO/N. Wolk

Release Date: April 14, 2026
Scale: Image is about 20 arcmin (13 light-years) across.
Category: Normal Stars & Star Clusters and Exoplanets
Coordinates (J2000): RA: 3h 12m 00s | Dec: +63° 15' 00"
Constellation: Cassiopeia
Observation Date(s): 12 observations from Dec, 2022 to Apr, 2025
Observation Time: 52 hours and 52 minutes (2 days 4 hours 52 minutes)
Obs. IDs: 27348, 27413, 27414, 27587, 28762, 28829, 28830, 29078, 30791, 30792, 30897, 30898
Instrument: ACIS
References: Getman, K. et al. 2026, ApJ, accepted; arXiv:2512.12055
Color Code: X-ray: purple; Optical/IR: red, green, and blue
Distance Estimate: About 2,200 light-years from Earth

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Fast Facts for NGC 2353:



Credit: X-ray: NASA/CXC/Penn State Univ/K. Getman; Optical/IR: PanSTARRS; Image Processing: NASA/CXC/SAO/N. Wolk
Release Date: April 14, 2026
Scale: Image is about 20 arcmin (23 light-years) across.
Category: Normal Stars & Star Clusters and Exoplanets
Coordinates (J2000): RA: 7h 14m 30s | Dec: -10° 16' 00"
Constellation: Monoceros
Observation Date(s): 16 observations from Nov, 2022 to Sep, 2024
Observation Time: 80 hours and 44 minutes (3 days 8 hours 44 minutes)
Obs. IDs: 26500, 27044-27049, 27349, 27415, 27416, 29003, 29030, 29042, 29053, 29091, 29224
Instrument: ACIS
References: Getman, K. et al. 2026, ApJ, accepted; arXiv:2512.12055
Color Code: X-ray: purple; Optical/IR: red, green, and blue
Distance Estimate: About 3,900 light-years from Earth

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