Friday, March 27, 2026

A Solar System in the making? Two planets spotted forming in disc around young star

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VLT images of two planets forming around the young star WISPIT 2

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Composite VLT image of two planets around the WISPIT 2 star

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Spectrum of the baby exoplanet WISPIT 2c

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Wide-field view of the area around the WISPIT 2 star

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The young star WISPIT 2 in the constellation Aquila



Videos

Two planets spotted forming around a young star | ESO News
PR Video eso2604a
Two planets spotted forming around a young star | ESO News

Zooming into the young planetary system around the WISPIT 2 star
PR Video eso2604b
Zooming into the young planetary system around the WISPIT 2 star



Astronomers have observed two planets forming in the disc around a young star named WISPIT 2. Having previously detected one planet, the team have now employed European Southern Observatory (ESO) telescopes to confirm the presence of another. These observations, and the unique structure of the disc around the star, indicate that the WISPIT 2 system could resemble a young Solar System.

WISPIT 2 is the best look into our own past that we have to date,” says Chloe Lawlor, PhD student at the University of Galway, Ireland, and lead author of the study published today in The Astrophysical Journal Letters.

The system is only the second known, after PDS 70, where two planets have been directly observed in the process of forming around their host star. Unlike PDS 70, however, WISPIT 2 has a very extended planet-forming disc with distinctive gaps and rings. "These structures suggest that more planets are currently forming, which we will eventually detect,” Lawlor says.

"WISPIT 2 gives us a critical laboratory not just to observe the formation of a single planet but an entire planetary system," says Christian Ginski, study co-author and researcher at the University of Galway. With such observations, astronomers aim to better understand how baby planetary systems develop into mature ones, like our own.

The first newborn planet found in the system — named WISPIT 2b — was detected last year, with a mass almost five times that of Jupiter and orbiting the central star at around 60 times the distance between Earth and the Sun. “This detection of a new world in formation really showed the amazing potential of our current instrumentation,” said Richelle van Capelleveen, PhD student at Leiden Observatory, the Netherlands, and leader of the previous study. After an additional object was identified near the star [1], measurements made with ESO’s Very Large Telescope (VLT) and the VLT Interferometer (VLTI) confirmed its planetary nature. The new planet — WISPIT 2c — is four times closer to the central star and is twice as massive as WISPIT 2b. Both planets are gas giants, like the outer planets in our Solar System.

To confirm the existence of WISPIT 2c the team employed the SPHERE instrument on ESO's VLT, which captured an image of the object. The team then used the GRAVITY+ instrument on the VLTI to confirm that the object was indeed a planet. "Critically our study made use of the recent upgrade to GRAVITY+ without which we would not have been able to get such a clear detection of the planet so close to its star," says Guillaume Bourdarot, study co-author and researcher at the Max Planck Institute for Extraterrestrial Physics, Garching, Germany.

Both planets in WISPIT 2 appear in clear gaps within the disc of dust and gas circling the young star. These gaps result from each planet's development: particles in the disc accumulate, their gravity pulling in more material until an embryo planet forms. The remaining material, around each gap, creates distinctive dust rings in the disc.

Besides the gaps that the two planets were found in, there is at least one smaller gap farther out in the WISPIT 2 disc. "We suspect there may be a third planet carving out this gap" says Lawlor, "potentially of Saturn mass owing to the gap’s being much narrower and shallower". The team are eager to make follow-up observations, with Ginski noting that “with ESO’s upcoming Extremely Large Telescope, we may be able to directly image such a planet.


Source: ESO/News



Notes

[1] The first hints of the presence of a second planet came from observations made with the University of Arizona's MagAO-X on the 6.5-metre Magellan Telescopes in Chile and the University of Virginia's LMIRcam on the Large Binocular Telescope Interferometer in the USA.



More information

This research was presented in a paper to appear in The Astrophysical Journal Letters (https://doi.org/10.3847/2041-8213/ae4b3b).

The team is composed of C. Lawlor (School of Natural Sciences, Centre for Astronomy and Ryan Institute, University of Galway, Ireland [Galway]), R. F. van Capelleveen (Leiden Observatory, Leiden University,The Netherlands [Leiden]), G. Bourdarot (Max Planck Institute for Extraterrestrial Physics, Garching, Germany [MPE]), C. Ginski (Galway and Center for Astronomical Adaptive Optics, Department of Astronomy, University of Arizona, Tucson, USA [CAAO]), M. A. Kenworthy (Leiden), T. Stolker (Leiden), L. Close (CAAO), A. J. Bohn (Leiden), F. Eisenhauer (MPE and Department of Physics, Technical University of Munich, Garching, Germany), P. Garcia (Faculdade de Engenharia, Universidade do Porto, Portugal and CENTRA – Centro de Astrofísica e Gravitação, IST, Universidade de Lisboa, Portugal), S. F. Honig (School of Physics and Astronomy, University of Southampton, United Kingdom), J. Kammerer (European Southern Observatory, Garching Germany), L. Kreidberg (Max Planck Institute for Astronomy, Heidelberg, Germany), S. Lacour (LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, Meudon, France), J.-B. Le Bouquin (Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, France), E. Mamajek (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA), M. Nowak (LIRA), T. Paumard (LIRA), C. Straubmeier (1st Institute of Physics, University of Cologne, Germany), N. van der Marel (Leiden) and the exoGRAVITY Collaboration.

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.



Links


Contacts:

Chloe Lawlor
University of Galway
Galway, Ireland
Email:
c.lawlor13@universityofgalway.ie

Christian Ginski
University of Galway
Galway, Ireland
Email
: christian.ginski@universityofgalway.ie

Richelle van Capelleveen
Leiden Observatory, Leiden University
Leiden, the Netherlands
Email:
capelleveen@strw.leidenuniv.nl

Guillaume Bourdarot
Max Planck Institute for Extraterrestrial Physics
Garching, Germany
Tel: +498930000-3295
Email:
bourdarot@mpe.mpg.de

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


Thursday, March 26, 2026

A chemically rich outflow from a young Sun-like star: A new laboratory for shock chemistry

During the early stages of star formation, material is ejected at high speed from near the forming star forming a bipolar structure referred to as protostellar outflow. Credit: NASA, ESA, CSA, STScI



A study led by the Center for Astrochemical Studies (CAS) at MPE has revealed an unexpectedly rich chemical inventory in the outflow of the young, Sun-like protostar IRAS 4B1, located about 300 parsecs away in the star-forming region NGC 1333 in the Perseus molecular cloud. So far, there is only one low-mass protostellar outflow in which emission of complex organic molecules has been studied extensively, making IRAS 4B1 a rare and valuable laboratory for exploring how these molecules behave under extreme conditions.

One of the central questions in astrochemistry is how simple interstellar molecules grow into more complex species during the process of star and planet formation. As these processes unfold over millions of years, astronomers rely on snapshots of many systems at different evolutionary stages, using comparisons with theoretical models to trace the chemical evolution.

Protostellar outflows offer a unique window into these transformations. In the earliest stages of star formation, material is ejected from the young forming star at high speed. When this gas collides with the surrounding cloud, it generates shock waves that compress and briefly heat the gas and dust, rapidly altering the chemistry. These shocks can release complex organic molecules - defined as carbon-bearing species containing at least six atoms - that were previously frozen onto dust grains, injecting a burst of rich chemistry into the surrounding region.

Despite their importance, such detections are rare. “While working on a separate PRODIGE project mapping methyl cyanide (CH₃CN) toward IRAS 4B1, I noticed emission that appeared to trace the outflow rather than the hot surroundings of the forming star,” says Laura Busch, a postdoctoral researcher at MPE who led the study. “This made me search the data for more complex molecules – and I found them.”

The PRODIGE observations, carried out with the Northern Extended Millimeter Array (NOEMA), reveal a surprisingly diverse chemical composition in the outflow. “The combination of high sensitivity and broad spectral coverage makes PRODIGE ideally suited to this kind of study,” adds Jaime Pineda, scientist at MPE. “It allows us to detect and map multiple complex molecules simultaneously — something that would otherwise be extremely difficult.”

Maps of molecular emission show that different molecules trace distinct regions within the outflow, indicating variations in temperature and density. Some species are brightest where temperatures are highest, while others originate in cooler zones, reflecting different chemical pathways. These findings provide fresh insight into how complex organic molecules — the precursors of prebiotic chemistry — are processed by shocks during the earliest phases of star formation.

Source: Max Planck Institute for Extraterrestrial Physics (MPE)/Paper of the Month



The PROtostars & DIsks: Global Evolution (PRODIGE; PIs: P. Caselli and Th. Henning) is a collaboration between the Max Planck Society and the Institut de Radioastromie Millimétrique (IRAM) located in France. The project targeted a total of 30 Class 0/I protostellar systems in the Perseus molecular cloud, with the main goal of studying the kinematics of star formation. The observations cover a broad spectral bandwidth of 16GHz, a unique treat of the NOrthern Extended Millimeter Array (NOEMA) located in the French Alpes and run by IRAM that was used to observe the data, is essential for identifying molecules and study their emission spectra.



Contacts:

Dr. Laura Busch
Post-Doc

lbusch@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching
Center for Astrochemical Studies

Dr. Jaime Pineda Fornerod
Scientist
Tel:
+49 (0)89 30000-3610
Fax: +49 (0)89 30000-3950
jpineda@mpe.mpg.de
Max Planck Institute for Extraterrestrial Physics, Garching
Center for Astrochemical Studies



Publication

L. A. Busch, J. E. Pineda, P. Caselli, D. M. Segura-Cox, S. Narayanan, C. Gieser, M. J. Maureira, T.-H. Hsieh, Y. Lin, M. T. Valdivia-Mena, L. Bouscasse, Th. Henning, D. Semenov, A. Fuente, Y.-R. Chou, L. Mason, P. C. Cortés, L. W. Looney, I. W. Stephens, M. Tafalla, A. Dutrey, W. Kwon, P. Saha

PRODIGE - envelope to disk with NOEMA: VII. (Complex) organic molecules in the NGC1333 IRAS4B1 outflow: A new laboratory for shock chemistry
arXiv

Source | DOI


Wednesday, March 25, 2026

Smithsonian Astrophysical Observatory Receives $3.2M to Transform X-ray Astronomy for the Next Generation

The Lynx X-ray Observatory, which will adapt advanced manufacturing techniques developed in other industries and apply them to X-ray astronomy. Credit: G. Tremblay, CfA. High Resolution Image

The Lynx X-ray Observatory, which will adapt advanced manufacturing techniques developed in other industries and apply them to X-ray astronomy. High Resolution Image



The grant from the Gordon and Betty Moore Foundation will advance technology for the new Lynx X-ray Observatory, allowing astronomers to study the universe’s first supermassive black holes with better resolution than ever before.

Cambridge, MA (March Date, 2026) — The Gordon and Betty Moore Foundation has awarded the Smithsonian Astrophysical Observatory (SAO) $3.2 million to advance the key mirror technology for the new Lynx X-ray Observatory. Once launched, Lynx will dramatically improve sensitivity and imaging performance for X-ray astronomy.

The Moore Foundation grant will enable SAO, a part of the Center for Astrophysics | Harvard & Smithsonian (CfA), to expand technical work on an X-ray mirror system that increases the imaging capabilities of X-ray astronomy with 16x the field of view, up to 20x the spectral resolution, and 800x the surveying speed of current observatories.

“We need X-rays to confirm the identity of the earliest black holes forming,” said Randall Smith, associate director for science at the CfA, and lead PI on the project.

“Lynx is a transformational X-ray observatory that is designed to detect the first black holes and understand how they formed alongside the first galaxies.”

One of Lynx’s primary scientific goals is to observe the dawn of black holes, or the first black holes that formed in the early universe. Recent discoveries from NASA’s James Webb Space Telescope have revealed candidate early galaxies and compact objects, but X-ray observations are required to determine whether these sources contain actively forming black holes.

“We need X-rays to confirm the identity of the earliest black holes forming,” said Randall Smith, associate director for science at the CfA, and lead PI on the project. “Right now, our candidate sources are very bright in X-ray, but not for very long, and we need increased speed and resolution to observe and understand them. Lynx is a transformational X-ray observatory that is designed to detect the first black holes and understand how they formed alongside the first galaxies.”

The new mirrors enabled by the grant use modern fabrication methods, including ion beam forming, which shapes materials at the molecular level, to achieve the precision needed for next-generation X-ray astronomy.

“Technology from astronomy often is transferred out to other industries. For Lynx, we’re adapting advanced manufacturing techniques developed in other industries and applying them to X-ray astronomy,” said Peter Cheimets, telescope developer at the CfA, and an engineer for Lynx.

“This is not a spin-off of space technology, it’s a spin-in. By bringing these proven methods into astrophysics, and using them all at the same time, we can build mirrors with the precision, performance, speed, and cost needed to make Lynx possible.”

To date, the Moore Foundation has provided more than $28 million in support for black hole research and the launch of new projects at the CfA. With the new grant, Lynx joins the list of CfA-led black hole projects to be funded by Moore Foundation.

“CfA is leading the way in next-generation X-ray astronomy,” said Lisa Kewley, director of the CfA. “The support we’ve received, and continue to receive, from the Gordon and Betty Moore Foundation is crucial to supporting the cutting-edge observatories that will allow us to gain a deeper and clearer understanding of the universe for years to come.”




About the Center for Astrophysics | Harvard & Smithsonian/News

The Center for Astrophysics | Harvard & Smithsonian is a collaboration between Harvard and the Smithsonian designed to ask—and ultimately answer—humanity's greatest unresolved questions about the nature of the universe. The Center for Astrophysics is headquartered in Cambridge, MA, with research facilities across the U.S. and around the world.



About the Gordon and Betty Moore Foundation

The Gordon and Betty Moore Foundation advances scientific discovery, environmental conservation, and the special character of the San Francisco Bay Area. Visit moore.org and follow @MooreFound.



Media Contact:

Christine Buckley
Director of Communications
Center for Astrophysics | Harvard & Smithsonian
Tel: 617-599-9628

christine.buckley@cfa.harvard.edu


Tuesday, March 24, 2026

NASA’s Hubble Unexpectedly Catches Comet Breaking Up

This series of images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS) was taken over the course of three consecutive days: Nov. 8, 9, and 10, 2025. This is the first time Hubble has witnessed a comet so early in the process of breaking up. - Comet C/2025 K1 Compass Image - Credit: Image: NASA, ESA, Dennis Bodewits (AU); Image Processing: Joseph DePasquale (STScI)

This diagram shows the path Comet C/2025 K1 (ATLAS), or K1, took as it swung past the Sun and began its journey out of the solar system. NASA’s Hubble Space Telescope captured the inset image of the fragmenting comet just a month after K1’s closest approach to the Sun. Credit: Illustration: NASA, ESA, Ralf Crawford (STScI)





In a happy twist of fate, NASA’s Hubble Space Telescope just witnessed a comet in the act of breaking apart. The chance of that happening while Hubble watched is extraordinarily minuscule. The findings published Wednesday in the journal Icarus.

The comet K1, whose full name is C/2025 K1 (ATLAS)—not to be confused with interstellar comet 3I/ATLAS—was not the original target of the Hubble study.

“Sometimes the best science happens by accident,” said co-investigator John Noonan, a research professor in the Department of Physics at Auburn University in Alabama. “This comet got observed because our original comet was not viewable due to some new technical constraints after we won our proposal. We had to find a new target—and right when we observed it, it happened to break apart, which is the slimmest of slim chances.”

Noonan didn’t know K1 was fragmenting until he viewed the images the day after Hubble took them. “While I was taking an initial look at the data, I saw that there were four comets in those images when we only proposed to look at one,” said Noonan. “So we knew this was something really, really special.”

This is an experiment the researchers always wanted to do with Hubble. They had proposed many Hubble observations to catch a comet breaking up. Unfortunately, these are very difficult to schedule, and they were never successful.

“The irony is now we're just studying a regular comet and it crumbles in front of our eyes,” said principal investigator Dennis Bodewits, also a professor in Auburn University’s Department of Physics.

“Comets are leftovers of the era of solar system formation, so they’re made of ‘old stuff’—the primordial materials that made our solar system,” said Bodewits. “But they are not pristine—they've been heated; they've been irradiated by the Sun and by cosmic rays. So, when looking at a comet’s composition, the question we always have is, ‘Is this a primitive property or is this due to evolution?’ By cracking open a comet, you can see the ancient material that has not been processed.”

Hubble caught K1 fragmenting into at least four pieces, each with a distinct coma, the fuzzy envelope of gas and dust that surrounds a comet’s icy nucleus. Hubble cleanly resolved the fragments, but to ground-based telescopes, at the time they only appeared as barely distinguishable, bright blobs.

Hubble’s images were taken just a month after K1’s closest approach to the Sun, called perihelion. The comet’s perihelion was inside Mercury’s orbit, about one-third the distance of the Earth from the Sun. During perihelion, a comet experiences its most intense heating and maximum stress. Just past perihelion is when some long-period comets like K1 tend to fall apart.

Before it fragmented, K1 was likely a bit larger than an average comet, probably around 5 miles across. The team estimates the comet began to disintegrate eight days before Hubble viewed it. Hubble took three 20-second images, one on each day from Nov. 8 through Nov. 10, 2025. As it watched the comet, one of K1’s smaller pieces also broke up.

Because Hubble’s sharp vision can distinguish extremely fine details, the team could trace the history of the fragments back to when they were one piece. That allowed them to reconstruct the timeline. But in doing so, they uncovered a mystery: Why was there a delay between when the comet broke up and when bright outbursts were seen from the ground? When the comet fragmented and exposed fresh ice, why didn’t it brighten almost instantaneously?

The team has some theories. Most of a comet’s brightness is sunlight reflected off of dust grains. But when a comet cracks open, it reveals pure ice. Maybe a layer of dry dust needs to form over the pure ice and then blow off. Or maybe heat needs to get below the surface, build up pressure, and then eject an expanding shell of dust.

“Never before has Hubble caught a fragmenting comet this close to when it actually fell apart. Most of the time, it's a few weeks to a month later. And in this case, we were able to see it just days after,” said Noonan. “This is telling us something very important about the physics of what's happening at the comet’s surface. We may be seeing the timescale it takes to form a substantial dust layer that can then be ejected by the gas.”

The research team is looking forward to finishing the analysis of the gases to come from the comet. Already, ground-based analysis shows that K1 is chemically very strange—it is significantly depleted in carbon, compared with other comets. Spectroscopic analysis from Hubble’s STIS (Space Telescope Imaging Spectrograph) and COS (Cosmic Origins Spectrograph) instruments is likely to reveal much more about the composition of K1 and the very origins of our solar system, as NASA’s space telescopes continue to contribute to our understanding of planetary science.

The comet K1 is now a collection of fragments about 250 million miles from Earth. Located in the constellation Pisces, it is heading out of the solar system, not likely to ever return.

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.




Monday, March 23, 2026

Extremely Rare Second-Generation Star Discovered Inside Ancient Relic Dwarf Galaxy

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Pictor II ultra-faint dwarf galaxy

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Star PicII-503 in Pictor II ultra-faint dwarf galaxy

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Star PicII-503 in Pictor II ultra-faint dwarf galaxy

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Galactic Center Illuminates Cerro Tololo’s Blanco 4-Meter Telescope

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Víctor M. Blanco 4-meter Telescope with DECam

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Pictor (Annotated)




The star is the first unambiguous example of chemical enrichment by the first stars in the Universe within a primordial environment

Discovered in the Pictor II dwarf galaxy, star PicII-503 has an extreme deficiency in iron — less than 1/40,000th of the Sun. This signature makes it the clearest example of a star within a primordial system that preserves the chemical enrichment of the Universe’s first stars. PicII-503 also has an extreme overabundance of carbon, providing the missing link to connect carbon-enhanced stars observed in the Milky Way halo to an origin in ancient dwarf galaxies.

Astronomers have discovered one of the most chemically primitive stars ever identified — an ancient stellar relic that preserves the chemical imprint of the very first stars in the Universe. This star, named PicII-503, resides in the tiny, ultra-faint dwarf galaxy Pictor II. The discovery was enabled by the U.S. Department of Energy-fabricated Dark Energy Camera (DECam), mounted on the U.S. National Science Foundation Víctor M. Blanco 4-meter Telescope, at NSF Cerro Tololo Inter-American Observatory (CTIO) in Chile, a Program of NSF NOIRLab.

Pictor II is located in the constellation Pictor. It contains several thousand stars and is more than ten billion years old. PicII-503 lies on the outskirts of the galaxy, and it contains less iron than any other star ever measured outside of the Milky Way, while also having an extreme overabundance of carbon. These signatures unmistakably match those of carbon-enhanced stars found in the outer reaches of the Milky Way, whose origins have, until now, been a mystery.

The study was led by Anirudh Chiti, Brinson Prize Fellow at Stanford University, and the results are presented in a paper appearing in Nature Astronomy.

The first stars in the Universe formed from gas that contained only the simple elements, hydrogen and helium. Within their fiery cores, this first generation of stars created the first elements heavier than helium, such as carbon and iron, which astronomers refer to as “metals.” When these stars exploded, they released their heavy elements into the interstellar medium to be recycled into the next generation of stars.

Second-generation stars are like time capsules, preserving the low amounts of heavy elements released during the explosive deaths of first-generation stars. By searching for these rare, low-metallicity stars and deriving their chemistry, scientists can better understand the mechanisms of initial element production in the Universe.

PicII-503 is the first unambiguous example of a second-generation star in an ultra-faint dwarf galaxy. It was uncovered in data from the DECam MAGIC (Mapping the Ancient Galaxy in CaHK) survey, a 54-night observing program designed to identify the oldest and most chemically primitive stars in the Milky Way and its dwarf galaxy companions. Using a specialized narrow-band filter sensitive to calcium absorption features, astronomers were able to estimate the metal content of thousands of stars from imaging data alone.

Among the hundreds of stars near Pictor II, MAGIC data singled out PicII-503 as an exceptionally metal-poor candidate, allowing researchers to target it for detailed follow-up study. “Without data from MAGIC, it would have been impossible to isolate this star among the hundreds of other stars in the vicinity of the Pictor II ultra-faint dwarf galaxy,” says Chiti.

By combining data from MAGIC, the Magellan/Baade Telescope, and ESO’s Very Large Telescope, the team found that PicII-503 has the lowest iron and calcium abundances ever measured outside of the Milky Way. This paucity of iron and calcium makes it the first object that clearly preserves enrichment from the first stars in a relic dwarf galaxy.

“Discovering a star that unambiguously preserves the heavy metals from the first stars was at the edge of what we thought possible, given the extreme rarity of these objects,” says Chiti. “With the lowest iron abundance ever derived in any ultra-faint dwarf galaxy, PicII-503 provides a window into initial element production within a primordial system that is unprecedented.”

Even more remarkably, the team discovered that PicII-503 has a carbon-to-iron ratio that is over 1500 times that of the Sun. This overabundance matches the distinct carbon signature of low-iron stars long observed in the Milky Way halo. These are known as carbon-enhanced metal-poor stars, and their origin has remained unknown until now.

One hypothesis is that carbon-enhanced metal-poor stars are second-generation stars that preserve the chemical elements produced by low-energy supernovae of first-generation stars. During this process, heavy elements that form close to the star’s interior, like iron, fall back into the remnant compact object, while lighter elements that are near the star’s outer regions, like carbon, are ejected into the interstellar medium to seed the formation of the next generation of stars.

PicII-503 supports the low-energy supernovae explanation because it is found in one of the smallest dwarf galaxies that we know of. If the supernova that produced the metals found in PicII-503 was high-energy, then the elements would have escaped the gravitational pull of the small Pictor II dwarf galaxy. PicII-503 also demonstrates that the carbon-enhanced metal-poor stars observed in the Milky Way halo likely originated from ancient relic dwarf galaxies that have, over time, merged with ours.

“What excites me the most is that we have observed an outcome of the very initial element production in a primordial galaxy, which is a fundamental observation!” says Chiti. “It also cleanly connects to the signature that we have seen in the lowest-metallicity Milky Way halo stars, tying together their origins and the first-star-enriched nature of these objects.”

“Discoveries like this are cosmic archaeology, uncovering rare stellar fossils that preserve the fingerprints of the Universe’s first stars,” says Chris Davis, NSF Program Director for NOIRLab. “We look forward to many more discoveries with the start of the NSF–DOE Rubin Observatory’s Legacy Survey of Space and Time later this year.”

PicII-503 offers a rare, direct glimpse into the Universe’s first chapter of chemical evolution, which is a foundational moment that ultimately set the stage for planets, chemistry, and life itself. It also connects long-standing mysteries about ancient stars in the Milky Way to their origins in primordial dwarf galaxies.




More information

This research was presented in a paper titled “Enrichment by the first stars in a relic dwarf galaxy” appearing in Nature Astronomy. DOI: 10.1038/s41550-026-02802-z

The team is composed of A. Chiti (Stanford University/University of Chicago/Brinson Prize Fellow, USA) , V. M. Placco (NSF NOIRLab, USA), A. B. Pace (University of Virginia, USA), A. P. Ji (University of Chicago/NSF-Simons AI Institute for the Sky, USA), D. S. Prabhu (University of Arizona, USA), W. Cerny (Yale University, USA), G. Limberg (University of Chicago, USA), G. S. Stringfellow (Yale University, USA), A. Drlica-Wagner (Fermi National Accelerator Laboratory/Stanford University/University of Chicago/NSF-Simons AI Institute for the Sky, USA), K. R. Atzberger (University of Virginia, USA), Y. Choi (NSF NOIRLab, USA), D. Crnojević (University of Tampa, USA), P. S. Ferguson (University of Washington, USA), N. Kallivayalil (University of Virginia, USA), N. E. D. Noël (University of Surrey, UK), A. H. Riley (Durham University, UK/Lund University, Sweden), D. J. Sand (University of Arizona, USA), J. D. Simon (Observatories of the Carnegie Institution for Science, USA), A. R. Walker (Cerro Tololo Inter-American Observatory/NSF NOIRLab, Chile), C. R. Bom (Centro Brasileiro de Pesquisas Físicas, Brazil), J. A. Carballo-Bello (Universidad de Tarapacá, Chile), D. J. James (ASTRAVEO LLC, Applied Materials Inc., USA), C. E. Martínez-Vázquez (NSF NOIRLab, USA), G. E. Medina (University of Toronto, Canada), K. Vivas (NSF NOIRLab, Chile).

NSF NOIRLab, the U.S. National Science Foundation center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), NSF Kitt Peak National Observatory (KPNO), NSF Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and NSF–DOE Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona.

The scientific community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence of I’oligam Du’ag to the Tohono O’odham Nation, and Maunakea to the Kanaka Maoli (Native Hawaiians) community.



Links



Contacts:

Anirudh Chiti
Brinson Prize Fellow
Stanford University
Email:
achiti@stanford.edu

Josie Fenske
Public Information Officer
NSF NOIRLab
Email:
josie.fenske@noirlab.edu


Sunday, March 22, 2026

NuSTAR Hunts for the Source of a Gamma-Ray Burst

Gamma-ray bursts are thought to be mostly associated with the explosion of stars or the merger of compact objects to form black holes. In the explosion, two jets of very fast-moving material are ejected, as depicted in this artist’s illustration. If a jet happens to be aimed at Earth, we see a brief but powerful gamma-ray burst. Image credit: ESO/A. Roquette.  Download Image

A little over a week ago, a rare and exceptionally bright gamma-ray burst (GRB) illuminated NuSTAR’s shields and imaging detectors. Typically associated with the collapse of massive stars or the merger of compact objects like neutron stars, GRBs are the most luminous explosions in the Universe. They allow us to investigate the origin of heavy elements, test general relativity in extreme environments, and even constrain the Hubble constant. This event, dubbed GRB 260226A, is particularly significant as it was only the second GRB in 17 years to trigger the onboard algorithm of the Large Area Telescope on NASA’s Fermi Gamma-ray Space Telescope. NuSTAR’s shields are primarily designed to reject background due to charged particles, but bright GRBs can show up as a signal in the shields, so they are continuously monitored by the NuSTAR Search for INteresting Gamma-ray Signals (SINGS) team to hunt for such events and occasionally they can be bright enough to show up on the detectors themselves.

Despite intensive search campaigns by several ground-based optical telescopes across the world, the exact location of GRB 260226A remains a mystery. However, the spectacular detection of this GRB in NuSTAR’s broadband imaging detectors allowed the SINGS team to collaborate with the InterPlanetary Network and narrow the sky localization of the burst. The team is now going a step beyond by leveraging NuSTAR’s deep imaging sensitivity and wide field-of-view to precisely locate the source. This week, NuSTAR is conducting a Director’s Discretionary Time observation to scan the localization region and identify the elusive counterpart. Pinpointing the location will enable the broader astronomical community to perform deep, multi-wavelength follow-up of this rare event, further demonstrating NuSTAR’s vital and evolving role in high-energy time-domain astrophysics.

Author: Gaurav Waratkar (Postdoctoral Scholar, Caltech)



Tiny NASA Spacecraft Delivers Exoplanet Mission’s First Images

This pair of images shows stars observed Feb. 6, 2026, by the SPARCS space telescope simultaneously in the near-ultraviolet, left, and far-ultraviolet, right. The fact that one star is seen in the far-UV while multiple are seen in near-UV offers insights into the temperatures of these stars, with the one visible in both colors being the hottest. Credit: NASA/JPL-Caltech/ASU



The SPARCS cube satellite is ready to begin studying low-mass stars and to reveal details about the habitability of the planets they host.

With the first images from the spacecraft now in hand, the team behind NASA’s Star-Planet Activity Research CubeSat, or SPARCS, is ready to begin charting the energetic lives of the galaxy’s most common stars to help answer one of humanity’s most profound questions: Which distant worlds beyond our solar system might be habitable?

Initial, or “first light,” images mark the moment a mission proves its instruments are functioning in space and ready to transition to full science operations. This milestone is especially important for SPARCS, whose observations depend on highly precise ultraviolet (UV) measurements, making the demonstration of the camera’s performance critical to achieving its science goals. The spacecraft launched Jan. 11; the images came down Feb. 6 and were subsequently processed.

Roughly the size of a large cereal box, SPARCS will monitor flares and sunspot activity on low-mass stars — objects only 30% to 70% the mass of the Sun. These stars are among the most common in the Milky Way and host the majority of the galaxy’s roughly 50 billion habitable-zone terrestrial planets, which are rocky worlds close enough to their stars for temperatures that could allow liquid water and potentially support life.

“Seeing SPARCS’ first ultraviolet images from orbit is incredibly exciting. They tell us the spacecraft, the telescope, and the detectors are performing as tested on the ground and we are ready to begin the science we built this mission to do,” says SPARCS Principal Investigator Evgenya Shkolnik, professor of Astrophysics at the School of Earth and Space Exploration at Arizona State University, which leads the mission.

The SPARCS spacecraft is the first dedicated to continuously and simultaneously monitoring the far-ultraviolet and near-ultraviolet radiation from low-mass stars for extended periods. Over its one-year mission, SPARCS will target approximately 20 low-mass stars and observe them over durations of five to 45 days.

Although such stars are small, dim, and cool compared to the Sun, they are also known to flare far more frequently than our solar system’s star. The flares can dramatically affect the atmospheres of the planets they host. Understanding the host star is key to understanding a planet’s habitability.

Future focused

“I am so excited that we are on the brink of learning about exoplanets’ host stars and the effect of their activities on the planets’ potential habitability,” said Shouleh Nikzad, the lead developer of the SPARCS camera (dubbed SPARCam) and the chief technologist at NASA’s Jet Propulsion Laboratory in Southern California. “I’m doubly excited that we are contributing to this mission with detector and filter technologies we developed at JPL’s Microdevices Laboratory.” Created in 1989, the facility is where inventors harness physics, chemistry, and material science, including quantum, to deliver first-of-their-kind devices and capabilities for the nation.

The filters were made using a technique that improves sensitivity and performance by enabling them to be directly deposited onto the specially developed UV-sensitive “delta-doped” detectors. The approach of detector-integrated filters eliminated the need for a separate filter element, resulting in a system that is among the most sensitive of its kind ever flown in space.

“We took silicon-based detectors — the same technology as in your smartphone camera — and we created a high-sensitivity UV imager. Then we integrated filters into the detector to reject the unwanted light. That is a huge leap forward to doing big science in small packages,” Nikzad said, “and SPARCS serves to demonstrate their long-term performance in space.”

This technology paves the way for future missions like NASA’s next potential UV-capable flagship mission, the Habitable Worlds Observatory mission concept, as well as smaller interim missions, such as the agency’s forthcoming UVEX (UltraViolet EXplorer), which is led by Caltech in Pasadena.

The mission takes advantage of advances in computational processing as well, with an onboard computer that can perform data processing and intelligently adjust the observation parameters to better sample the development of flares as they happen.

“The SPARCS mission brings all of these pieces together — focused science, cutting-edge detectors, and intelligent onboard processing — to deepen our understanding of the stars that most planets in the galaxy call home,” said David Ardila, SPARCS instrument scientist at JPL. “By watching these stars in ultraviolet light in a way we’ve never done before, we’re not just studying flares. These observations will sharpen our picture of stellar environments and help future missions interpret the habitability of distant worlds.”




More about SPARCS

Funded by NASA and led by Arizona State University, SPARCS is managed under the agency’s Astrophysics Research and Analysis program. The agency’s CubeSat Launch Initiative (CSLI) selected SPARCS in 2022 for a ride to orbit. The initiative is a low-cost pathway for conducting scientific investigations and technology demonstrations in space, enabling students and faculty to gain hands-on experience with flight hardware design, development, and building.

Blue Canyon Technologies fabricated the spacecraft bus.



News Media Contact

Matthew Segal
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-8307

matthew.j.segal@jpl.nasa.gov

Alise Fisher / Karen Fox
NASA Headquarters, Washington
202-358-2546 / 202-385-1287

alise.m.fisher@nasa.gov / karen.c.fox@nasa.gov

Kim Baptista
Arizona State University, School of Earth and Space Exploration
480-727-4662

Kim.Baptista@asu.edu


Saturday, March 21, 2026

Spring Collection: Spring Has Sprung in Space (As Always)

Westerlund 2 - NGC 346 - Cygnus OB3
Cat's Paw Nebula (NGC 6334) - Pelican Nebula (NGC 7000) - Flame Nebula (NGC 2024)

Visual Description: Spring Collection

This release features a series of composite images, each highlighting a different star-forming region, or "stellar nursery". The bright, colorful images are individually labeled, and presented in a three by two grid.

The first image, in the grid's upper left, features a young star cluster known as Westerlund 2. Here, scores of gleaming white specks ringed in neon pink are scattered across the image in a band that stretches from our lower right to our upper left, and beyond. The pink data represent stars seen with Chandra. Clouds of brick-orange dust enter the image from our lower left, and spread along the bottom edge of the frame.

Centered at the top of the grid is NGC 346, a star-forming region in the Small Magellanic Cloud. Here, tiny specks in golden orange, neon blue, and white, are scattered across a dark blue sky. Long streaks of hazy cloud coalesce on the left side of the image. A large, bright, neon pink X-ray cloud, seen with Chandra, hangs in the upper right.

In the upper right corner of the grid is Cygnus OB3, the most mature stellar nursery in the batch. Here, tiny white gleaming specks fill a black sky tinged with golden orange and silver haze. Several larger white spheres with faint outer rings in blues and greens dot the image, including a black hole and a massive star at the center of the frame.

In the second row of the grid, at our lower left, is a composite image of the Cat's Paw Nebula. Here, pockets of starry blue sky appear behind thick, overlapping rings of dark orange cloud. At the center of the image, tucked amongst the clouds, is a mottled patch of purple. This patch represents X-ray data gathered by Chandra. Centered at the bottom of the grid is the Pelican Nebula. Here, a hazy blue sky dotted with pink, white, and golden specks stretches across much of the frame. A dense, dark-orange cloud enters the composite image from lower right. Long, finger-like tendrils grow out of the cloud, as if reaching for distant baby stars.

And finally, at the lower righthand corner of the grid, is a composite image of the Flame Nebula. Here, a dense dusty-grey haze blankets the frame. Several dozen young stars light up the dust and gas cloud, white at the core with thick, neon purple-pink halos showing X-rays collected by Chandra.




  • This week, the Earth passes the point in its orbit when days in the northern hemisphere become longer than nights and spring begins.

  • This collection of spring-themed images is meant to celebrate the “flowering” that occurs throughout space.

  • There are six star-forming regions in these composite images, containing X-rays from Chandra and data from other telescopes.

  • The objects are NGC 7000 (aka, the Pelican Nebula), the Cat’s Paw Nebula, NGC 346, the Flame Nebula, Westerlund 2, and Cygnus OB3.



In the Northern Hemisphere this week, the calendar officially passes from winter into spring when the length of the day and the night become equal as the days become longer. Meanwhile, there are places in space where blooms of the stellar variety are always growing.

This collection of images from NASA’s Chandra X-ray Observatory and other telescopes contains regions where stars are forming. Often nicknamed “stellar nurseries,” they are cosmic gardens from which stars – not plants – emerge from the interstellar soil of gas and dust. X-rays are energetic enough that they can penetrate the gas and dust of these stellar nurseries, giving insight to the young stars and other high-energy phenomena that are happening within, including the effects of X-rays on any planets or planet-forming disks orbiting stars.

And, like gardens here on Earth, some stellar nurseries bloom before others. These images are listed roughly by their age, representing a span from “early” to “late spring,” cosmically speaking.

The Pelican Nebula (also known as NGC 7000) and the Cat’s Paw Nebula both contain stars that are mainly about a million years old. By comparison, the Sun is over 4.5 billion years old — or more than 4,000 times the age of these stars. In this new image of the Pelican Nebula, X-rays from Chandra (pink) are combined with an optical image from NASA’s Hubble Space Telescope (red, green, and blue). Meanwhile, the Cat’s Paw Nebula image has Chandra X-ray data (pink) overlaid on infrared data from NASA’s James Webb Space Telescope (red, orange, yellow, green, cyan and blue).

For stars that are slightly older — with ages between about one and three million years old — we look to NGC 346, the Flame Nebula, and Westerlund 2. For NGC 346, a star-forming region in the Small Magellanic Cloud, X-rays from Chandra (purple) are combined with an optical image from Hubble (red, green, and blue). In the Flame Nebula composite, Chandra’s X-rays (purple) are found throughout the gas and dust-filled landscape in infrared light seen by NASA’s James Webb Space Telescope (red, green, and blue). This Westerlund 2 image contains X-ray data from Chandra (purple) and infrared data from Webb (red, orange, green, cyan, and blue).

The most mature stars in these spring-themed images is the region around Cygnus X-1, a binary system where a black hole is partnered with a massive star. In this image of the Cygnus OB3 region, X-rays from Chandra (blue) are combined with optical data from Kitt Peak National Observatory (red and blue).

The companion star to the black hole in Cygnus X-1 is particularly interesting. Because it more than 20 times more massive than the Sun, it is likely going to explode in a supernova in the future. This event would seed the area with new elements that will become the cosmic soil for the next generation of stars.

This process of supernova explosions sending essential elements out into space will happen to many of the most massive stars in these stellar nurseries, underscoring the similar rhythms between the cycle of life here on Earth and the cycle of the stars across space.

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.




Visual Description:

This release features a series of composite images, each highlighting a different star-forming region, or "stellar nursery". The bright, colorful images are individually labeled, and presented in a three by two grid.

The first image, in the grid's upper left, features a young star cluster known a Westerlund 2. Here, scores of gleaming white specks ringed in neon pink are scattered across the image in a band that stretches from our lower right to our upper left, and beyond. The pink data represent stars seen with Chandra. Clouds of brick-orange dust enter the image from our lower left, and spread along the bottom edge of the frame.

Centered at the top of the grid is NGC 346, a star-forming region in the Small Magellanic Cloud. Here, tiny specks in golden orange, neon blue, and white, are scattered across a dark blue sky. Long streaks of hazy cloud coalesce on the left side of the image. A large, bright, neon pink X-ray cloud, seen with Chandra, hangs in the upper right.

In the upper right corner of the grid is Cygnus OB3, the most mature stellar nursery in the batch. Here, tiny white gleaming specks fill a black sky tinged with golden orange and silver haze. Several larger white spheres with faint outer rings in blues and greens dot the image, including a black hole and a massive star at the center of the frame.

In the second row of the grid, at our lower left, is a composite image of the Cat's Paw Nebula. Here, pockets of starry blue sky appear behind thick, overlapping rings of dark orange cloud. At the center of the image, tucked amongst the clouds, is a mottled patch of purple. This patch represents X-ray data gathered by Chandra.

Centered at the bottom of the grid is the Pelican Nebula. Here, a hazy blue sky dotted with pink, white, and golden specks stretches across much of the frame. A dense, dark-orange cloud enters the composite image from lower right. Long, finger-like tendrils grow out of the cloud, as if reaching for distant baby stars.

And finally, at the lower righthand corner of the grid, is a composite image of the Flame Nebula. Here, a dense dusty-grey haze blankets the frame. Several dozen young stars light up the dust and gas cloud, white at the core with thick, neon purple-pink halos showing X-rays collected by Chandra.



Fast Facts for Westerlund 2:

Credit: X-ray: NASA/CXC/SAO/Sejong Univ./Hur et al; Infrared: ESA/Webb, NASA & CSA, V. Almendros-Abad, M. Guarcello, K. Monsch, and the EWOCS team. Image Processing: NASA/CXC/SAO/L. Frattare and K. Arcand
Release Date: March 19, 2026
Scale: Image is about 2.1 arcmin (12 light-years) across.
Category: Normal Stars & Star Clusters
Coordinates (J2000): RA: 10h 23m 58.60s | Dec: -57° 44' 40.62"
Constellation: Carina
Observation Date(s): 3 pointings from Aug 2003 to Sep 2006
Observation Time: 37 hours and 30 minutes (1 day 13 hours 30 minutes)
Obs. IDs: 3501, 6410, 6411
Instrument: ACIS
Color Code: X-ray: purple; Infrared: red, orange, green, cyan, and blue
Distance Estimate: About 20,000 light-years from Earth



Fast Facts for NGC 346:

Credit: X-ray: NASA/CXC/SAO; Optical: ESA/Hubble and NASA, A. Nota, P. Massey, E. Sabbi, C. Murray, M. Zamani (ESA/Hubble); Image Processing: NASA/CXC/SAO/L. Frattare
Release Date: March 19, 2026
Scale: Image is about 3.8 arcmin (220 light-years) across.
Category: Normal Stars & Star Clusters
Coordinates (J2000): RA: 00h 59m 05.1s | Dec: -72° 10' 33.2"
Constellation: Tucana
Observation Date(s): May 15, 2001
Observation Time: 27 hours 25 minutes (1 days 3 hours 25 minutes)
Obs. IDs: 1881
Instrument: ACIS
Color Code: X-ray: purple; Optical: red, green, and blue
Distance Estimate: About 200,000 light-years from Earth



Fast Facts for Cygnus OB3:

Credit: X-ray: NASA/CXC/SAO; Optical: T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOIRLab/NSF/AURA). Image Processing: NASA/CXC/SAO/L. Frattare
Release Date: March 19, 2026
Scale: Image is about 26.5 arcmin (50 light-years) across.
Category: Normal Stars and Star Clusters & Black Holes
Coordinates (J2000): RA: 19h 58m 22s | Dec: +35° 12' 6"
Constellation: Cygnus
Observation Date(s): 3 observations from Jan 2002 to Apr 2003
Observation Time: 14 hours 18 minutes
Obs. IDs: 2742, 2743, 3814
Instrument: ACIS
Color Code: X-ray: blue; Optical: H-alpha: red, and Sulphur [S II]: blue
Distance Estimate: About 6,500 light-years from Earth



Fast Facts for Cat's Paw Nebula (NGC 6334):

Credit: X-ray: NASA/SAO/CXC; Infrared: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/J. Major
Release Date: March 19, 2026
Scale: Image is about 72 arcmin (91 light-years) across.
Category: Normal Stars and Star Clusters
Coordinates (J2000): RA: 5h 46m 45.8s | Dec: +0° 0′ 08.1"
Constellation: Scorpius
Observation Date(s): 10 observations from Aug 2002 to Jul 2016
Observation Time: 85 hours 28 minutes (3 days 13 hours 28 minutes)
Obs. IDs: 2573, 2574 ,3844, 4591, 8975, 12382, 13436, 18082, 18081, 18876
Instrument: ACIS
Color Code: X-ray: pink; Infrared: red, orange, yellow, green cyan, and blue
Distance Estimate: About 4,370 light-years from Earth



Fast Facts for Pelican Nebula (NGC 7000):

Credit: X-ray: NASA/CXC/SAO/F. Damiani; Optical: J. Bally/University of Colorado, B. Reipurth/University of Hawaii and NOIRLab/NSF/AURA; Image Processing: NASA/CXC/SAO/L. Frattare
Release Date: March 19, 2026
Scale: Image is about 19.3 arcmin (0.9 light-years) across.
Category: Normal Stars and Star Clusters
Coordinates (J2000): RA: 20h 50m 48s | Dec: +44° 21′ 0"
Constellation: Cygnus
Observation Date(s): 2 observations on Nov 20, 2012
Observation Time: 12 hours 6 minutes
Obs. IDs: 13647, 15592
Instrument: ACIS
Color Code:  X-ray: purple; Optical: red, green, and blue Distance Estimate: About 1,800 light-years from Earth



Fast Facts for Flame Nebula (NGC 2024):

Credit: X-ray: NASA/CXC/PSU/K. Getman, E. Feigelson, M. Kuhn & the MYStIX team; JWST Image: NASA, ESA, CSA,STScI, M. Meyer (University of Michigan), M. De Furio (UT Austin), M. Robberto (STScI), A. Pagan (STScI); Image Processing: NASA/CXC/SAO/L. Frattare

 

Release Date: March 19, 2026
Scale: Image is about 2.2 arcmin (1 light-years) across.
Category: Normal Stars and Star Clusters
Coordinates (J2000): RA: 05h 41m 46.30s | Dec: -01° 55′ 28.70"
Constellation: Orion
Observation Date(s): 1 observation Aug 2001
Observation Time: 20 hours 57 minutes
Obs. IDs: 1878
Instrument: ACIS
Color Code: X-ray: purple; Infrared: red, green, and blue
Distance Estimate: About 1,350 light-years from Earth


Friday, March 20, 2026

We are Not Alone: Our Sun Escaped From Galactic Center Together with Stellar “Twins”

A mass migration of stellar twins. Stars similar to our Sun form a mass migration from the center of the Milky Way Galaxy, occurring approximately 4 to 6 billion years ago. Credit: NAOJ. Download Image (578KB) - Download Movie (33MB)



Researchers have uncovered evidence that our Sun was part of a mass migration of similar “twins” leaving the core regions of our Galaxy, 4 to 6 billion years ago. The team created and studied an unprecedentedly accurate catalogue of stars and their properties using data from the European Space Agency’s Gaia satellite. This discovery sheds light on the evolution of our Galaxy, particularly the development of the rotating bar-like structure at its center.

While archaeology on Earth studies the human past, galactic archaeology traces the vast journeys of stars and galaxies. For example, scientists know that our Sun was born around 4.6 billion years ago, more than 10,000 light-years closer to the center of the Milky Way than we are today. While studies of the composition of stars support this theory, this has long proven a conundrum to scientists. Observations reveal an enormous bar-like structure at our galactic center which creates a “corotation barrier,” which makes it difficult for stars to escape so far from the center.

So how did we get here? To answer this question, a team led by Assistant Professors Daisuke Taniguchi from Tokyo Metropolitan University and Takuji Tsujimoto from the National Astronomical Observatory of Japan undertook an unprecedentedly large study of solar “twins,” stars which have very similar temperature, surface gravity, and composition to our Sun. They used data taken by the European Space Agency’s Gaia satellite mission, a daunting trove of observations covering two billion stars and other objects. They created a catalogue of 6,594 stellar “twins,” a collection around 30 times larger than previous surveys.

From this immense list, they were able to obtain the most accurate picture to date of the ages of these stars, carefully correcting for the selection bias of stars which are easier to see. Looking at the distribution of ages, they noticed a broad peak for stars around 4 to 6 billion years old: this includes our Sun, and is evidence for similar stars of similar age, positioned around the same distance from the center of the Galaxy. This means that our Sun is not at its current position by accident, but as part of a much larger stellar migration.

This discovery sheds light not only on the nature of our Solar System, but also the evolution of the Galaxy itself. The corotation barrier created by the bar structure at the galactic center would not allow for such a mass egress. However, the story changes if the bar was still being formed at the time. The ages of our stellar “twins” reveal not only when the mass escape occurred, but also the time range over which the bar was formed.

The center of the Galaxy is a far less hospitable environment for the evolution of life than the outer regions. The team’s findings thus illuminate a key factor in how our Solar System, and in turn our planet, found itself in a region of the Galaxy where organisms could develop and evolve.

In the future the team hopes to use precise observations of the stars similar in age to the Sun to look for stars born near the same time and place as the Sun to determine the point of origin and travel route of the mass migration. It is expected that the Japanese JASMINE astrometry satellite mission being developed by the National Astronomical Observatory of Japan will contribute to this research.




Detailed Article(s)

We are Not Alone: Our Sun Escaped From Galactic Center Together with Stellar “Twins”
JASMINE Project



Release Information

Researcher(s) Involved in this Release
  • Daisuke Taniguchi (Tokyo Metropolitan University)
  • Takuji Tsujimoto (National Astronomical Observatory of Japan)

Coordinated Release Organization(s)

  • Tokyo Metropolitan University
  • National Astronomical Observatory of Japan, NINS

Paper(s)

  • Daisuke Taniguchi et al. “Solar twins in Gaia DR3 GSP-Spec I. Building a large catalog of Solar twins with ages”, in Astronomy and Astrophysics, DOI:10.1051/0004-6361/202658913

  • Takuji Tsujimoto et al. “Solar twins in Gaia DR3 GSP-Spec II. Age distribution and its implications for the Sun's migration”, in Astronomy and Astrophysics (Letter to the Editor) DOI: 10.1051/0004-6361/202658914

Related Link(s)