Friday, March 13, 2026

ALMA Detects Extremely Abundant Alcohol in Interstellar Comet 3I/ATLAS

An artist's impression of 3I/ATLAS is shown as it passes near the Sun, illuminating one side of the comet. On the side of the comet closer to the sun, the methanol gas is shown in blue, with icy dust grains still present in the gas. On the dark side of the comet, the hydrogen cyanide is shown in orange. Credit: NSF/AUI/NSF NRAO/M.Weiss


Astronomers capture a chemical snapshot of planet formation beyond our solar system

Comet 3I/ATLAS continues to make astonishing headlines, thanks to new findings from astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), of which the U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO) is a partner. This new research reveals that 3I/ATLAS is packed with an unusually large amount of the organic molecule methanol – more than almost all known comets in our own solar system.

“Observing 3I/ATLAS is like taking a fingerprint from another solar system,” shares Nathan Roth, lead author on this research, and a professor with American University, “The details reveal what it’s made of, and it’s bursting with methanol in a way we just don’t usually see in comets in our own solar system.”

Using ALMA’s Atacama Compact Array in Chile, on multiple dates in late 2025, the team observed 3I/ATLAS as it approached our Sun. As sunlight warmed its icy surface, 3I/ATLAS released gas and dust, forming a glowing halo (or coma) around its core. By analyzing this coma, astronomers revealed the chemical fingerprints of the material it is composed of, allowing them to study how objects might be made in another planet,ary system, without leaving our own.

The team focused on the faint submillimeter fingerprints of two molecules: methanol (CH₃OH), a type of alcohol, and hydrogen cyanide (HCN), a nitrogen-bearing organic molecule commonly seen in comets. The ALMA data reveal that 3I/ATLAS is heavily enriched in methanol compared to hydrogen cyanide, far beyond what is typically seen in comets born in our own solar system. On two observing dates, the team measured methanol‑to‑HCN ratios of about 70 and 120, placing 3I/ATLAS among the most methanol‑rich solar system comets ever studied.

These measurements imply that the icy material from 3I/ATLAS was formed by (or experienced) very different conditions than those that shape most comets in our own solar system. Previous work with the James Webb Space Telescope has shown that 3I/ATLAS had a coma dominated by carbon dioxide when it was far from the Sun, and these new ALMA results add methanol as another unusual detail in its chemical inventory.

ALMA’s high resolution for imaging also allowed the team to see how different molecules move away from the comet, revealing surprising differences between methanol and hydrogen cyanide. Hydrogen cyanide appears to come, for the most part, directly from the comet’s core, or nucleus, which is typical for comets in our solar system. Methanol, on the other hand, appears to come from both the nucleus AND from ice particles in the coma. These tiny, icy grains act like mini-comets: as the object moves closer to the Sun, where ice turns into gas, they also release methanol. Similar behavior has been observed in some solar system comets, but this is the first time the physics of such detailed outgassing has been traced in an interstellar object.

​Comet 3I/ATLAS is only the third confirmed object ever seen passing through our solar system from interstellar space, after 1I/‘Oumuamua and 2I/Borisov. Observations of these objects also revealed unusual properties. As astronomers continue to discover and study more interstellar objects, our understanding of planet formation in other planetary systems continues to grow more interesting.



Press Contacts:

Jill Malusky
Sr. Public Information Group Manager and Public Information Officer
Email | Phone


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

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

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

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Thursday, March 12, 2026

A Sea of Light: HETDEX Astronomers Reveal Hidden Structures in the Young Universe

Section of the Line Intensity Map created by charting the distribution and concentration of excited hydrogen (via the Lyman alpha wavelength) in the universe ten billion years ago. The stars mark where HETDEX has found galaxies. The inset simulates the structure present in this map once it is zoomed in on and background noise is removed from the data. Credit: Maja Lujan Niemeyer/Max Planck Institute for Astrophysics/HETDEX, Chris Byrohl/Stanford University/HETDEX

Example of a spectrum created by statistically combining the spectra of 50,000 Lyman alpha emitters from the first Public HETDEX Source Catalog. The wavelength associated with Lyman alpha appears as a dramatic peak, making it a particularly useful tool for identifying the location of bright galaxies in the early universe. Credit: HETDEX


An international team of astronomers has created the most detailed 3D map yet of Lyman alpha light emitted by hydrogen in the early universe. Using Line Intensity Mapping on data by the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), they identified faint galaxies and gas that were previously difficult to observe. This can now be compared to simulations of the structures in the early universe. The team processed half a petabyte of data to refine their map, revealing unseen objects and enhancing our understanding of galaxy evolution.

Astronomers with the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), have used data from the project to make the largest, most accurate 3D map yet of the light emitted by excited hydrogen in the early universe, 9 billion to 11 billion years ago. This specific form of light, called Lyman alpha, is emitted in large quantities when hydrogen atoms are exposed to a star’s energy. That makes it a great tool for finding bright galaxies in this far-off time, which experienced a rash of star creation. However, the locations of fainter galaxies and gas, which also emit Lyman alpha, have remained largely unknown.

“Observing the early universe gives us an idea of how galaxies evolved into their current form, and what role intergalactic gas played in this process,” said Maja Lujan Niemeyer, a HETDEX scientist and recent graduate from the Max Planck Institute for Astrophysics who led the development of the map. “But because they are far away, many objects in this time are faint and difficult to observe.”

Using a technique called Line Intensity Mapping, the new map pulls these objects into view, adding shape and nuance to this formative era in our universe. Results were published on March 3 in The Astrophysical Journal.

All light can be broken apart into its various wavelengths. The result is called a spectrum. Astronomers examine spectra (the plural of “spectrum”) for peaks and valleys which correspond to the presence of different elements. Line Intensity Mapping charts the distribution and concentration of specific elements across an entire region, rather than observing objects one-by-one.”

“Imagine you're in a plane looking down. The ‘traditional’ way to do galaxy surveys is like mapping the brightest cities only: you learn where the big population centers are, but you miss everyone thatlives in the suburbs and small towns,” explained Julian Muñoz, a HETDEX scientist, assistant professor at The University of Texas at Austin, and co-author on the paper. “Intensity mapping is like viewing the same scene through a smudged plane window: you get a blurrier picture, but you capture all the light and not just the brightest spots.

”Although Line Intensity Mapping isn’t a new technique, this is the first time it’s been used to chart Lyman alpha emissions in such a large set of data and with such high precision. Using the Hobby-Eberly Telescope at McDonald Observatory, HETDEX is charting the position of over one million bright galaxies in its quest to understand dark energy. The project is unique in gathering so much data – over 600 million spectra – for such a large swath of sky, measuring over 2,000 full Moons.

“However, we only use a small fraction of all the data we collect, around 5%,” explained Karl Gebhardt, HETDEX principal investigator, chair of UT Austin’s astronomy department, and co-author on the paper. “There’s huge potential in using that remaining data for additional research.”

“HETDEX observes everything in a patch of sky, but only a tiny amount of that data is related to the galaxies that are bright enough for the project to use,” added Lujan Niemeyer. “But those galaxies are only the tip of the iceberg. There’s a whole sea of light in the seemingly empty patches in between.”

To create its map, the team wrote custom programming and used supercomputers at the Texas Advanced Computing Center to sift through roughly half a petabyte of HETDEX data. It then used the location of bright galaxies already identified by HETDEX to calculate the location of fainter galaxies and gas glowing nearby. Thanks to gravity’s propensity for making matter clump together, where there is one bright galaxy, other objects are sure to be close.”

“So, we can use the location of known galaxies as a signpost to identify the distance of the fainter objects,” said Eiichiro Komatsu, a HETDEX scientist, scientific director at the Max Planck Institute for Astrophysics, and co-author on the paper. The resulting map brings the regions around bright galaxies into greater focus and adds detail to the stretches in between.

“We have computer simulations of this period,” continued Komatsu. “But those are just simulations, not the real universe. Now we have a foundation which can let us know if some of the astrophysics underpinning those simulations is correct.”

Moving forward, the team hopes to compare their map with others that overlap the same region of the universe and focus on different elements. For example, a Line Intensity Map of carbon monoxide - which is associated with the dense, cold clouds where stars form - could add insight to the conditions surrounding the young stars emitting Lyman alpha wavelengths.

“This study is a first detection, which is exciting on its own, and it opens the door to a new era of intensity-mapping the universe,” said Muñoz. “The Hobby-Eberly is a pioneering telescope. And with new, complementary instruments coming online, we're entering a golden age for mapping the cosmos.”



Contacts:

Lujan Niemeyer
Postdoc
Tel: 2357
maja@mpa-garching.mpg.de

Eiichiro Komatsu
Director
Tel: 2208
komatsu@mpa-garching.mpg.de


Original publication

Maja Lujan Niemeyer, Eiichiro Komatsu, José Luis Bernal et al.
Lyα Intensity Mapping in HETDEX: Galaxy-Lyα Intensity Cross-Power Spectrum
published on March 3 in The Astrophysical Journal.

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Wednesday, March 11, 2026

ESA’s Mars orbiters watch solar superstorm hit the Red Planet

How charged solar particles, blasted out on 20 May 2024, spread through the Solar System and reached planets including Mars.


What happens when a solar superstorm hits Mars? Thanks to the European Space Agency’s Mars orbiters, we now know: glitching spacecraft and a supercharged upper atmosphere.

In May 2024, Earth was hit by the biggest solar storm recorded in over 20 years. It sent our planet’s atmosphere into overdrive, triggering shimmering auroras that were seen as far south as Mexico.

This storm also hit Mars. Fortunately, ESA’s two Mars Orbiters – Mars Express and ExoMars Trace Gas Orbiter (TGO) – were in the right place at the right time, with a radiation monitor aboard TGO picking up a dose equivalent to 200 ‘normal’ days in just 64 hours.

A new study published today in Nature Communications now reveals in greater depth how this intense, stormy activity affected the Red Planet.

“The impact was remarkable: Mars’s upper atmosphere was flooded by electrons,” says ESA Research Fellow Jacob Parrott, lead author of the study. “It was the biggest response to a solar storm we’ve ever seen at Mars.”

The superstorm caused a dramatic increase in electrons in two distinct layers of Mars’s atmosphere at altitudes of around 110 and 130 km, with numbers rising by 45% and a whopping 278%, respectively. This is the most electrons we’ve ever seen in this layer of martian atmosphere.

“The storm also caused computer errors for both orbiters – a typical peril of space weather, as the particles involved are so energetic and hard to predict,” adds Jacob. “Luckily, the spacecraft were designed with this in mind, and built with radiation-resistant components and specific systems for detecting and fixing these errors. They recovered fast.”

Pioneering a new technique

To investigate the superstorm’s impact on Mars, Jacob and colleagues used a technique currently being pioneered by ESA known as radio occultation.


First, Mars Express beamed a radio signal to TGO at the very moment it was disappearing over the martian horizon. As TGO vanished, the radio signal was bent (‘refracted’) by the various layers of Mars’s atmosphere before being picked up by the orbiter, allowing scientists to glean more about each layer. The researchers also used observations from NASA’s MAVEN mission to confirm the electron densities.

“This technique has actually been used for decades to explore the Solar System, but using signals beamed from a spacecraft to Earth,” says Colin Wilson, ESA project scientist for Mars Express and TGO, and co-author of the study. “It’s only in the past five years or so that we’ve started using it at Mars between two spacecraft, such as Mars Express and TGO, which usually use those radios to beam data between orbiters and rovers. It’s great to see it in actio.”

ESA uses orbiter-to-orbiter radio occultation routinely at Earth, and plans to use it more regularly in future planetary missions.

Different worlds, different weather

The superstorm was experienced very differently at Earth and Mars, highlighting the differences between the two worlds.

At Earth, the response of the upper atmosphere was more muted, thanks to the shielding effect of Earth’s magnetic field. As well as deflecting a lot of solar storm particles away from Earth, the magnetic field also diverted some towards Earth’s poles, where they caused the sky to light up with auroras.

“This technique has actually been used for decades to explore the Solar System, but using signals beamed from a spacecraft to Earth,” says Colin Wilson, ESA project scientist for Mars Express and TGO, and co-author of the study. “It’s only in the past five years or so that we’ve started using it at Mars between two spacecraft, such as Mars Express and TGO, which usually use those radios to beam data between orbiters and rovers. It’s great to see it in action.”

ESA uses orbiter-to-orbiter radio occultation routinely at Earth, and plans to use it more regularly in future planetary missions.

Different worlds, different weather

The superstorm was experienced very differently at Earth and Mars, highlighting the differences between the two worlds.

At Earth, the response of the upper atmosphere was more muted, thanks to the shielding effect of Earth’s magnetic field. As well as deflecting a lot of solar storm particles away from Earth, the magnetic field also diverted some towards Earth’s poles, where they caused the sky to light up with auroras.


While their differences can make it tricky to compare planets directly, understanding how solar activity impacts the residents of the Solar System – in other words, space weather forecasting – is hugely important. At Earth, solar storms can be dangerous and damaging for astronauts and equipment up in space, and can disrupt our satellites and systems (power, radio, navigation) further down.

However, studying space weather is difficult as the Sun throws out radiation and material erratically, making targeted measurements largely opportunistic. “Fortunately, we were able to use this new technique with Mars Express and TGO just 10 minutes after a large solar flare hit Mars. Currently we’re only performing two observations per week at Mars, so the timing was extremely lucky,” adds Jacob.

Jacob and colleagues captured the aftermath of three solar events – all part of the same storm, but different in terms of what they throw out into space, and how they do it: one flare of radiation, one burst of high-energy particles, and an eruption of material known as a coronal mass ejection (CME).

Together, these events sent fast-moving, energetic, magnetised plasma and X-rays flooding towards Mars. When this barrage of material hit the planet’s upper atmosphere it collided with neutral atoms and stripped away their electrons, causing the region to fill up with electrons and charged particles.

SOHO’s view of the 11 May 2024 solar storm
Access the video

“The results improve our understanding of Mars by revealing how solar storms deposit energy and particles into Mars’s atmosphere – important as we know the planet has lost both huge amounts of water and most of its atmosphere to space, most likely driven by the continual ;wind of particles streaming out from the Sun,” says Colin.

“But there’s another side to it: the structure and contents of a planet’s atmosphere influence how radio signals travel through space. If Mars’s upper atmosphere is packed full of electrons, this could block the signals we use to explore the planet’s surface via radar, making it a key consideration in our mission planning – and impacting our ability to investigate other worlds.”



Notes for editors

‘Martian ionospheric response during the May 2024 solar superstorm’ by J. Parrott et al. is published today in Nature Communications. DOI: 10.1038/s41467-026-69468-z

Jacob Parrott began this work as an ESA Young Graduate Trainee, continued it as a postgraduate student at Imperial College London, and is now a Research Fellow at ESA’s European Space Research and Technology Centre (ESTEC) in the Netherlands.

The May 2024 solar storm was monitored and observed after it struck Earth by numerous ESA missions and covered in a number of subsequent web stories, including:

Several ESA missions are either currently or soon-to-be keeping an eye on our star. ESA’s Solar Orbiter is continuously observing the Sun up close and tracking its activity (including the May 2024 superstorm). Solar Orbiter will soon be joined by Smile, a mission to understand how Earth’s magnetic field responds to the solar wind scheduled to launch in spring 2026, and later by Vigil (2031), which will spot potentially hazardous solar activity in near-real-time.

. The initial dose of radiation delivered to Mars orbit by the solar storm, measured by TGO in May 2025, was,hr reported in Semkova et al.: doi.org/10.1016/j.lssr.2025.02.010


For more information please contact:

ESA Media Relations
media@esa.int

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Tuesday, March 10, 2026

Two observatories, one cosmic eye

Image Description: Two images of a planetary nebula in space. The image to the left, labelled “Euclid & Hubble”, shows the whole nebula and its surroundings. A star in the very centre is surrounded by white bubbles and loops of gas, all shining with a powerful blue light. Farther away a broke.n ring of red and blue gas clouds surrounds the nebula. The background shows many stars and distant galaxies. A white box indic,brates the centre of the nebula and this region is the image to the right, labelled “Hubble”. It shows the multi-layered bubbles, poin.ted jets and circular shells of gas that make up the nebula, as well as the central star, in greater detail. Credit: ESA/Hubble ,hr& NASA, ESA Euclid/Euclid Consortium/NASA/Q1-2025, J.-C. Cuillandre & E. Bertin (CEA Paris-Saclay), Z. Tsvetanov


For this month’s ESA/Hubble Picture of the Month, we turn our gaze to one of the most visually intricate remnants of a dying star: the Cat’s Eye Nebula, also known as NGC 6543. This extraordinary planetary nebula lies in the constellation Draco and has captivated astronomers for decades with its elaborate and multilayered structure. Observations with ESA’s Gaia mission place the nebula at a distance of 4 400 light years away.

Planetary nebulae, so-called because of their round shape when viewed through early telescopes, are in fact expanding gas thrown off by stars in their final stages of evolution. It was the Cat’s Eye Nebula itself where this fact was first discovered in 1864 —examining the spectrum of its light reveals the emission from individual molecules that’s characteristic of a gas, distinguishing planetary nebulae from stars and galaxies.

The NASA/ESA Hubble Space Telescope also revolutionised our understanding of planetary nebulae; its detailed images showed that the simple, circular appearance of a planetary nebula seen from the ground belies a very complex morphology. This was particularly true of the Cat’s Eye Nebula, where Hubble’s images in 1995 revealed never-before-seen structures that broadened our understanding of how planetary nebulae come to be.

This time, Hubble is joined by ESA’s Euclid space telescope to create a new image of NGC 6543. The nebula is showcased through the combined eyes of Hubble and Euclid, revealing the remarkable complexity of stellar death in this object. Though primarily designed to map the distant Universe, Euclid captures the Cat’s Eye Nebula as part of its deep imaging surveys. In Euclid’s wide, near-infrared and visible light view, the arcs and filaments of the nebula’s bright central region are situated within a halo of colourful fragments of gas zooming away from the star. This ring was ejected from the star at an earlier stage, before the main nebula at the centre formed. The whole nebula stands out against a backdrop teeming with distant galaxies, demonstrating how local astrophysical beauty and the farthest reaches of the cosmos can be seen together with Euclid.

Within this broad view of the nebula and its surroundings, Hubble captures the very core of the billowing gas with high-resolution visible-light images, adding extra detail in the centre of this image. The data reveal a tapestry of concentric shells, jets of high-speed gas and dense knots sculpted by shock interactions, features that appear almost surreal in their intricacy. These structures are believed to record episodic mass loss from the dying star at the nbula’s centre, creating a kind of cosmic “fossil record” of its final evolutionary stages.

Combining the focused view of Hubble with Euclid’s deep field observations not only highlights the nebula’s exquisite structure, but also places it within the broader context of the Universe that both space telescopes explore. Together, these missions provide a rich and complementary view of NGC 6543 — revealing the delicate interplay between stellar end-of-life processes and the vast cosmic tapestry beyond.



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Monday, March 09, 2026

Listen to This Month's "Planetary Parade" with NASA's Chandra



  • Three new Chandra sonifications of data of Jupiter, Saturn, and Uranus have been released.

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  • Planets and other Solar System bodies can reflect X-rays given off by the Sun, which Chandra can detect.

  • Sonification is a process that translates data captured by Chandra and other telescopes into sound.

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  • In addition to X-rays from Chandra, these new sonifications contain data from Hubble, Cassini, and Keck telescopes.


In late February, people in the Northern Hemisphere can look up for a special sight: Six planets will all be visible from clear and dark night skies. New sonifications from NASA’s Chandra X-ray Observatory released Wednesday will help commemorate this latest “planetary parade.”

Because the planets in our solar system travel around the Sun in the same plane (known as the ecliptic), they will sometimes appear bunched together in the sky when their orbits find them on the same side of the Sun at the same time. When this happens, it looks like the planets have roughly formed a line from our vantage point on Earth.

In Chandra’s sonifications, which translate astronomical data into sound, three of the planets that will be on display — Jupiter, Saturn, and Uranus — can be seen and heard in ways that they cannot from Earth.

While Chandra is best known for its X-ray insight into black holes and other extreme objects, the telescope has also played an important role in the exploration of our solar system. The Sun gives off X-rays that travel out into the solar system and can be reflected by planets, moons, and other bodies. This gives astronomers a unique window into certain physics that cannot be discovered through other kinds of telescopes.

The sonification of Jupiter combines X-ray data from Chandra with an infrared image from NASA’s Hubble Space Telescope. Woodwind sounds reveal Chandra’s X-ray data, including emission from the planet’s auroras. More instruments join in to represent the planet’s complex cloud layers. Next, through the combination of an optical image from NASA’s Cassini mission and X-rays from Chandra, listeners can experience Saturn like never before. A siren-like sound follows the arc of the rings, and different tones of synthesizers play as the scan passes the planet itself. Finally, listeners can hear the ice giant Uranus through the data collected by Chandra and the W.M. Keck Observatory. The data in this sonification reflects the amount of light detected from the planet and the orientation of its ring.

The process of creating a sonification preserves the integrity of the data, which arrives on Earth as a series of ones and zeroes (binary code), and shifts it into a form that can be processed through hearing. Sonifications expand options for people to explore what telescopes discover in space, an example of NASA’s ongoing commitment to share its data as widely as possible.



Jupiter:

In this image, the amount of diffuse X-rays from a donut-shaped ring of energetic particles around Jupiter, seen on the left and right side of the planet, has been enhanced compared to the amount of X-rays from the planet's auroras, seen at the poles. As the scan moves left to right, it encounters X-rays that bracket the planet on either side, and this plays as woodwind sounds. As we pass over the planet itself, seen in an infrared image from NASA’s Hubble Space Telescope, the sounds become fuller as the infrared data is represented by other instruments. Since Jupiter is tilted slightly, the pitch descends as the scan passes over the bright band near the equator and through the Great Red Spot. On the other side, more X-ray data from Chandra flanks the planet and can be heard as gusty wind sounds at the end.


Saturn:

The scan of Saturn begins on the right and moves to the left. As it encounters Saturn’s famous rings, seen in an optical image from the Cassini mission, listeners hear a siren effect whose frequency follows the arc of the rings. Once the scan reaches the planet itself, the sounds change, to lower tones with a dark synthetic bass sound. This distinguishes the rings from the planet. Chandra’s X-rays are heard as higher synthetic tones that mark where high-energy activity is found across the planet, rings, and poles.


Uranus:

Returning to the left to right scan, the sounds begin with a cello that traces the arcing ring — not as famous as Saturn’s but still prominent — around the ice giant Uranus. The notes change to represent the amount of reflected light and its location on Uranus as seen in an optical light image from the W.M. Keck Observatory. The X-rays detected by Chandra, which come from X-rays from the Sun that are reflected, are heard as higher frequencies as the scan passes over the pinkish region of the planet. The apparent asymmetry in the X-rays may not be a real effect because of the faint signal and the smoothing that was applied to the image.

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

For more on the Chandra sonification program, visit: https://chandra.si.edu/sound/




Visual Description:
This release features three sonifications, each focusing on a different planet in our solar system. The sonifications are presented as soundtracks to short videos. Each video features a composite image and an activation line. As the activation line sweeps across the image, it encounters visual elements. These elements are translated into sound, or sonified, according to parameters established by Chandra's sonification team.

The first sonification focuses on the planet Jupiter. At the center of the associated composite image is the gas giant itself; a seemingly perfect sphere with an atmosphere of latitudinal bands. The bands are different shades of grey, brown, and black, each with its own texture and width. Flanking Jupiter are neon pink and white clouds, representing X-rays from energetic particles in a ring around the planet. In the video, the activation line moves from our left to right. It first encounters a pink cloud, triggering whooshing woodwinds. When the activation line encounters Jupiter, dramatic low notes are triggered. Listen for the dip as the line passes over the Great Red Spot in Jupiter's southern hemisphere. The activation line continues toward our right, passing more pink X-ray clouds. The largest cloud, the last one encountered, has a bright white core, which translates to loud gusty woodwinds.

The second sonification focuses on the ringed planet, Saturn. In the composite image, the large gas giant fills the frame, its spherical outer layer a pale sandy grey. In this image, the wide bands of rings surrounding the planet are in shades of pale grey and sandy yellow. Here, Saturn is tilted away from us, making the round rings appear oval in shape. Dotting the planet are small pockets of neon blue. These represent reflected X-ray light observed by Chandra. In this video, the activation line moves from our right to left. When the line passes over the rings, a whooshing sounds spreads, conveying the widening middle of the oval shapes. Pockets of neon blue X-ray light trigger synthesizer sounds, with the pitch mapped to each pocket's vertical position in the image. When the line sweeps across Saturn's large round body, a low rumbling synth tone is triggered. The volume is linked to brightness, such that the low tone fades when the line reaches the shady side of the planet, on our left.
The third sonification features the planet Uranus. In the composite image, the icy giant is a greenish-blue cyan color, with a blush of neon pink X-rays hovering over its core. Uranus has a collection of very narrow rings, much finer than the wide disk-like rings surrounding Saturn. In this image, the fine rings are near vertical and slightly tilted, creating an oval shape with rounded points at our lower left and upper right. In this sonification, the activation line moves from our left to right. Brightness is mapped to volume and height is mapped to pitch, such that brighter objects at the top of the image sound louder and higher. Here, the curved oval shape of the rings is conveyed as a swooping cello note, with the pitch sliding up as the activation line passes the oval tilted toward our upper right.


Fast Facts for: Jupiter:

Credit: X-ray: NASA/CXC/SAO; Infrared: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/J. Major, S. Wolk; Sonification: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida)
Release Date: February 25, 2026
 Scale: Image is about 37 arcseconds across (Jupiter's diameter is 86,900 miles) as viewed from Earth.
 Category: Solar System
Observation Date(s): Dec 18, 2000
 Observation Time: 9 hours 57 minutes
 Obs. IDs: 18929, 20108-20110
 Instrument: ACIS
References: Elsner, R.F., et al, 2002, ApJ, 572, 1077; DOI 10.1086/340434
Color Code: X-ray: purple; Infrared: red, green, and blue
 Distance Estimate: About 383 million miles from Earth (at the start of Chandra observations)


Fast Facts for: Saturn:

Credit: X-ray: NASA/MSFC/CXC/A.Bhardwaj et al.; Optical: NASA/JPL-Caltech/SSI; Sonification: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida)
Release Date: February 25, 2026
 Scale: At the time of this observation, the angular diameter of the disk of Saturn was 20.5 arcsec.
 Category: Solar System
Observation Date(s): April 14, 2003; January 20, 2004; January 26, 2004
 Observation Time: 30 hours (1 day 6 hours)
 Obs. IDs: 3725, 4466, 4467
 Instrument: ACIS
References: A. Bhardwaj et al. The Astrophysical Journal, 627:L73, 2005 July 1 also astro-ph
Color Code: X-ray (Energy): blue; Optical: red, green, and blue
 Distance Estimate: An average distance of 886 million miles (1.4 billion kilometers) from Earth.


Fast Facts for Uranus:

Credit: X-ray: NASA/CXO/University College London/W. Dunn et al; Optical: W.M. Keck Observatory; Sonification; NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida), Cello by Johnny Mok
Release Date: February 25, 2026
 Scale: At the time of this observation, the angular diameter of the disk of Saturn was 20.5 arcsec.
 Category: Solar System
Observation Date(s): August 7, 2002
 Observation Time: 8 hours 13 minutes
 Obs. IDs: 2518
 Instrument: ACIS
References: Dunn, W. et al. 2021, JGR (accepted)
Color Code: X-ray (Energy): blue; Optical: red, green, and blue
 Distance Estimate: An average distance of 1.8 billion miles (2.9 billion kilometers) from Earth.

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Sunday, March 08, 2026

Intermediate Spiral Galaxy NGC 941


NGC 941 is located approximately 55 million light-years away in the constellation Cetus. This faint galaxy is classified as an intermediate spiral, exhibiting characteristics between a barred spiral with a central bar and an unbarred spiral. Overall, NGC 941 has a bluish appearance, and the presence of dust lanes in its central region indicates ongoing star formation. The small orange galaxies visible around it are actually much more distant background galaxies, seen through NGC 941 due to its low surface brightness. Credit: NAOJ; Image provided by Masayuki Tanaka


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NuSTAR Observes a Bursting Neutron Star

Artist's impression of the neutron star GS 1826–24, accreting material from its neighbor in a disk, and undergoing a bright thermonuclear burst that sends a flash through the system, illuminating its different components. Image credit: Futselaar (artsource) / Degenaar. Download Image

During the past week, NuSTAR targeted the X-ray binary GS 1826–24 in coordinated observations with the Karl G. Jansky Very Large Array (VLA) radio telescope, aiming to directly measure the speed of a jet launched by an accreting neutron star. This source recently entered an extraordinary state of rapid, clocklike thermonuclear bursts ignited on the neutron star surface. This produces a series of predictable, high-contrast, X-ray flashes that perturb the inner accretion flow and the associated jet of the neutron star binary system. NuSTAR precisely measures the burst onset and energetics, as well as the dynamical response of the inner accretion flow, while the VLA simultaneously tracks the compact radio jet. By measuring the lag between the X-ray burst and the jet’s radio response, the jet propagation speed can be directly determined — applying a novel burst-timing technique that was recently first demonstrated by the same team to measure the speed of the compact jet of the accreting neutron star 4U 1728−34 . At the same time, NuSTAR’s broadband X-ray coverage tracks how different components of the accretion flow — such as the boundary layer, corona, and inner disk — respond to each burst. This approach tests fundamental predictions for how relativistic jets are launched and powered in accreting compact objects.

Author: Nathalie Degenaar (Associate Professor, University of Amsterdam)


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Saturday, March 07, 2026

Astronomers Hate Them! This Star Formation Ingredient Makes Clusters Look 300 Million Years Older

This Hubble Space Telescope shows one of the most massive young star clusters in the Milky Way, nestled within the nebula NGC 3603. Credit: NASA, ESA, and the Hubble Heritage Team

Title: Characterizing The Star Cluster Populations in Stephan’s Quintet Using HST and JWST Observations
Authors: P. Aromal et al.
 First Author’s Institution: University of Western Ontario
 Status: Published in ApJ

This Hubble Space Telescope shows one of the most massive young star On 12 July 2022, the first images taken with JWST were released to the public. All of the astronomers in my department gathered together to watch the images be revealed in real time. It was exciting for everyone, from graduate students getting to see a glimpse into the future possibilities of their fields, to retired professors getting to see the fruits of their decades-long labor in advocating for the telescope to be built

One image that was showcased was of Stephan’s Quintet (Figure 1), an actively interacting galaxy group. We were all immediately impressed by the clarity of the star-forming regions in the dense gas between the galaxies in the image. Now, more than three years later, the authors of today’s article lay out a comprehensive study of the star clusters in those same regions, taking advantage of JWST’s multi-wavelength imaging capabilities.

Figure 1: The JWST imaging of Stephan’s Quintet with member galaxies labeled (including NGC 7320C, which is outside of the field of view). Gray arrows indicate the direction the associated galaxy is moving. The inlaid image shows the distribution of young star clusters in relation to the six main tidal features in the group. Inset image: Adapted from Aromal et al. 2025; Background image: NASA, ESA, CSA, STScI

HST + JWST = OMG!

While JWST’s depth and resolution are exciting for those studying high-redshift galaxies, for local-universe astronomers JWST really shines when used in combination with the Hubble Space Telescope (HST). The star clusters in Stephan’s Quintet were already cataloged in 2015 using HST, but the filters used in the imaging only captured optical and very-near-infrared wavelengths. If you want to get enough data to be able to accurately estimate the ages of these star clusters, especially accounting for reddening caused by surrounding dust, you need to push your imaging further into the infrared.

Unlike HST, JWST can take images in two wavelength filters at once, meaning you can get more data with roughly the same observing time. Here the authors imaged the same star clusters that HST looked at with five new JWST filters, all at longer infrared wavelengths than HST. Together, the authors had flux measurements at 10 different wavelengths across the optical and infrared spectrum for each star cluster, meaning they could perform spectral energy distribution fitting.

Go Ahead, Guess My Age

The best way to estimate an unresolved star cluster’s age is to get its full spectrum of light and fit spectroscopic models with varying ages to it until the model matches the observations. But, if you have individual brightness measurements at many different, spread-out wavelengths, you can still fit spectral models to the measurements and make a best guess despite the gaps in your full spectrum. Here the authors compare their multi-wavelength data to Code Investigating GALaxy Emission (CIGALE) spectral energy distribution models, allowing both the cluster ages and amount of dust extinction to vary.

This is where the long-wavelength JWST imaging is most necessary, because it is sometimes difficult to determine a cluster’s age with this method. For instance, is the light a cluster is giving off mostly red because its stars are very old, or is it because its stars are actually bluer and younger and the cluster just appears red due to foreground dust?

Infrared imaging can “see through” any dust and break this age–extinction degeneracy. For most of the clusters, the authors found that the original HST-only age estimates were accurate, but for 121 clusters in the sample (about 8% of the total), the JWST imaging made a significant change in the age estimates, shifting them to younger ages.

Where Do the Hip, Young Star Clusters Hang Out?

Once the authors had their updated ages for the clusters, they then mapped out where the clusters were located in Stephan’s Quintet and how hese clusters traced the known tidal structures in the group. Tidal structures are structures, usually consisting of gas, dust, and stars, that are formed from the tidal forces galaxies exert on one another as they interact and merge. The authors found that throughout all tidal regions of Stephan’s Quintet, there were many young, low-mass star clusters, all about 3–5 million years old. This timescale lines up with previous studies’ estimates of when NGC 7318B was thought to first fall into Stephan’s Quintet, compressing the gas in the group and creating tidal shocks that would trigger star formation.

Additionally, the authors’ star cluster age distribution for the group (see Figure 2) has a second, broader peak of higher-mass clusters with ages around 200 million years. This would correspond to when the most recent encounter between NGC 7320C (which has now passed through the group and is out of frame in Figure 1) and NGC 7319 is estimated to have occurred.

Figure 2: A histogram of the ages of all the star clusters in Stephan’s Quintet. The blue dashed line shows the estimates using only the HST data, and the orange solid line shows the estimates using both HST and JWST together. Notice how a lot of the clusters around 108 years old turned out to be less than 107 years old. Adapted from Aromal et al. 2025

Going even older, they found that the star clusters in the group that are more than 1 billion years old are also the most massive, and they are predominantly concentrated around NGC 7318A. This is the most massive elliptical galaxy in the group, and it’s the most likely to have a rich, old star cluster population, formed prior to any tidal interactions.

Taken together, the updated age measurements of the star clusters in Stephan’s Quintet provide not only a study of star formation history, but also of the galaxy–galaxy interaction history in the system!

Looking Ahead

While the authors have improved the age estimates of the clusters in Stephan’s Quintet, there are still limitations to their analysis. Their estimated star formation rate for the group is much lower than that estimated with other tracers, such as H-alpha emission, meaning this study may still be missing a fraction of very young star clusters. The most likely culprits are embedded clusters that haven’t had enough time to expel the surrounding gas from the massive clouds they formed within.

Future work will attempt to identify these embedded clusters using near-infrared JWST imaging, since in this study the authors focused only on the previously HST-identified clusters. In addition, combining their JWST data with high-resolution radio observations taken with the Atacama Large Millimeter/submillimeter Array will allow them to study the gas in the group more closely and understand how it influences the star formation.

This work highlights JWST’s excellent application to star cluster observations, building on the data we already have from decades of HST se, and it looks like we’re only just getting started!

Original astrobite edited by Skylar Grayson.



About the author, Veronika Dornan:
Veronika is a postdoctoral research associate at the University of Edinburgh. Her research is in observations of globular star clusters and how they can be used to study the evolution of their host galaxies.


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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Friday, March 06, 2026

Core Survey by NASA’s Roman Mission Will Unveil Universe’s Dark Side

This infographic describes the High-Latitude Wide-Area Survey that will be conducted by NASA’s Nancy Grace Roman Space Telescope. This observation program will cover more than 5,000 square degrees (about 12 percent of the sky) in just under a year and a half. Scientists will use the survey to analyze hundreds of millions of galaxies scattered across the cosmos that reveal clues about the universe’s shadowy underpinnings — dark matter and dark energy — as well as a wealth of other science topics. Credit: NASA’s Goddard Space Flight Center

This simulation shows the type of science astronomers will be able to do with future observations from NASA’s Nancy Grace Roman Space Telescope. The sequence demonstrates how the gravity of intervening galaxy clusters and dark matter can distort the light from farther objects, warping their appearance. More intervening material creates stronger distortions. By analyzing these features, astronomers can study elusive dark matter, which can only be measured indirectly through its gravitational effects on visible matter. As a bonus, the distortion acts like a telescope, enabling observations of extremely distant galaxies. Simulations like this one help astronomers understand what Roman’s future observations could tell us about the universe, and provide useful data to validate data analysis techniques. Caltech/IPAC/R. Hurt

This animation illustrates how small particles (in this case, sand) behave when exposed to different sound frequencies. In the very early universe, a cosmic “hum” created ripples in the primordial soup that filled space. Since the ripples were places where more matter was collected, like the rings of sand shown here, slightly more galaxies formed along them than elsewhere. As the universe expanded over billions of years, so did these structures. By comparing their size during different cosmic epochs, astronomers can trace the universe’s expansion. Nigel Stanford (used with permission)


The broadest planned survey by NASA’s upcoming Nancy Grace Roman Space Telescope will reveal hundreds of millions of galaxies scattered across the cosmos. After Roman launches as soon as this fall, scientists will use these sparkly beacons to study the universe’s shadowy underpinnings: dark matter and dark energy.

“We set out to build the ultimate wide-area infrared survey, and I think we accomplished that,” said Ryan Hickox, a professor at Dartmouth College in Hanover, New Hampshire, and co-chair of the committee that shaped the survey’s design. “We’ll use Roman’s enormous, deep 3D images to explore the fundamental nature of the universe, including its dark side.”

Roman’s High-Latitude Wide-Area Survey is one of the mission’s three core observation programs. It will cover more than 5,000 square degrees (about 12 percent of the sky) in just under a year and a half. Roman will look far from the dusty plane of our Milky Way galaxy (that’s what the “high-latitude” part of the survey name means), looking up and out of the galaxy rather than through it to get the clearest view of the distant cosmos.

“This survey is going to be a spectacular map of the cosmos, the first time we have Hubble-quality imaging over a large area of the sky,” said David Weinberg, an astronomy professor at Ohio State University in Columbus, who played a major role in devising the survey. “Even a single pointing with Roman needs a whole wall of 4K televisions to display at full resolution. Displaying the whole high-latitude survey at once would take half a million 4K TVs, enough to cover 200 football fields or the cliff face of El Capitan.”

The survey will combine the powers of imaging and spectroscopy to unveil a goldmine of galaxies strewn across cosmic time. Astronomers will use the survey’s data to explore invisible dark matter, detectable only via its gravitational effects on other objects, and the nature of dark energy — a pressure that seems to be speeding up the universe’s expansion.

“Cosmic acceleration is the biggest mystery in cosmology and maybe in all of physics,” Weinberg said. “Somehow, when we get to scales of billions of light years, gravity pushes rather than pulls. The Roman wide area survey will provide critical new clues to help us solve this mystery, because it allows us to measure the history of cosmic structure and the early expansion rate much more accurately than we can today.”

Weighing shadows

Anything that has mass warps space-time, the underlying fabric of the universe. Extremely massive things like clusters of galaxies warp space-time so much that they distort the appearance of background objects — a phenomenon called gravitational lensing.

“It’s like looking through a cosmic funhouse mirror,” Hickox said. “It can smear or duplicate distant galaxies, or if the alignment is just right, it can magnify them like a natural telescope.”

Roman’s view will be large and sharp enough to study this lensing effect on a small scale to see how clumps of dark matter warp the appearance of distant galaxies. Astronomers will create a detailed map of the large-scale distribution of matter — both seen and unseen — throughout the universe and fill in more of the gaps in our understanding of dark matter. Studying how structures grow over time will also help astronomers explore dark energy’s strength at various cosmic stages.

“The data analysis standards required to measure weak gravitational lensing are such that the astronomy community as a whole will benefit from very high-quality data over the full survey area, which will undoubtedly lead to unexpected discoveries,” said Olivier Doré, a senior research scientist at NASA’s Jet Propulsion Laboratory in Southern California, who leads a team focused on Roman imaging cosmology with the High-Latitude Wide-Area Survey. “This survey will accomplish much more than just revealing dark energy!” While NASA’s Hubble and James Webb space telescopes both also study gravitational lensing, the breakthrough with Roman is its large field of view.

“Weak lensing distorts galaxy shapes too subtly to see in any single galaxy — it’s invisible until you do a statistical analysis,” Hickox said. “Roman will see more than a billion galaxies in this survey, and we estimate about 600 million of them will be detailed enough for Roman to study these effects. So Roman will trace the growth of structure in the universe in 3D from shortly after the big bang to today, mapping dark matter more precisely than we’ve ever done before.”

Sounding out dark energy

Roman’s wide-area survey will also gather spectra from around 20 million galaxies. Analyzing spectra helps show how the universe expanded during different cosmic eras because when an object recedes, all of the light waves we receive from it are stretched out and shifted toward redder wavelengths — a phenomenon called redshift.

By determining how quickly galaxies are receding from us, carried by the relentless expansion of space, astronomers can find out how far away they are — the more a galaxy’s spectrum is redshifted, the farther away it is. Astronomers will use this phenomenon to make a 3D map of all the galaxies measured within the survey area out to about 11.5 billion light-years away.

That will reveal frozen echoes of ancient sound waves that once rippled through the primordial cosmic sea. For most of the universe’s first half-million years, the cosmos was a dense, almost uniform sea of plasma (charged particles).

Rare, tiny clumps attracted more matter toward themselves gravitationally. But it was too hot for the material to stick together, so it rebounded. This push and pull created waves of pressure—sound — that propagated through the plasma.

Over time, the universe cooled and the waves ceased, essentially freezing the ripples (called baryon acoustic oscillations) in place. Since the ripples were places where more matter was collected, slightly more galaxies formed along them than elsewhere. As the universe expanded over billions of years, so did these structures.

These rings act like a ruler for the universe. Today, they are about 500 million light-years wide. Roman will precisely measure their size across cosmic time, revealing how dark energy may have evolved.

Recent results from other telescopes hint that dark energy may be shifting in strength over cosmic time. “Roman will be able to make high precision tests that should tell us whether these hints are real deviations from our current standard model or not,” said Risa Wechsler, director of Stanford University’s KIPAC (Kavli Institute for Particle Astrophysics and Cosmology) in California and co-chair of the committee that shaped the survey’s design. “Roman’s imaging survey combined with its redshift survey give us new information about the evolution of the universe — both how it expands and how structures grow with time — that will help us understand what dark energy and gravity are doing at unprecedented precision.”

Altogether, Roman will help us understand the effects of dark energy 10 times more precisely than current measurements, helping discern between the leading theories that attempt to explain why the expansion of the universe is speeding up.

Because of the way Roman will survey the universe, it will reveal everything from small, rocky objects in our outer solar system and individual stars in nearby galaxies to galaxy mergers and black holes at the cosmic frontier over 13 billion years ago.

“Roman is exciting because it covers such a wide area with the image quality only available in space,” Wechsler said. “This enables a broad range of science, from things we can anticipate studying to discoveries that we haven’t thought of yet.”

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



By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Media contact:

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

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Thursday, March 05, 2026

Proto-stellar disks in their natural habitat

Figure 1: Young disks observed with ALMA at a wavelength of 3 mm. These disks clearly display substructure and the early presence of companion stars. from: Maureira et al., 2025, A&A, 705, A96

Figure 2: Zoom simulations of proto-stellar disk formation inside a molecular cloud (large image). The colour scale indicates the the gas column densities. The insets show multiple zoom regions, in which several dense cores have formed. Six cores (labels and orange borders) were studied in more detail. © MPA

Figure 3: High resolution views of the resulting proto-stellar disks for various simulations of Core 1: the ‘control’ case without magnetic fields called ‘hydro’ (left), the absence of a disk with ‘ideal’ MHD (middle), and the disk forming in the most realistic ‘non-ideal’ MHD simulation (right), including ambipolar diffusion. © MPA


Sun-like stars form within turbulent molecular clouds, encircled by disks of gas and dust - the birthplaces of planets. While the earliest phases of the disk assembly process are obscured by the surrounding dense gas, ALMA can observe proto-stellar disks shortly after their formation. In a project supported by the Excellence Cluster ORIGINS, researchers from MPA, MPE, Harvard, and the University of Cologne performed high-resolution non-ideal magneto-hydrodynamical simulations that self-consistently follow proto-stellar disk formation from their parental turbulent molecular clouds down to stellar scales, spanning over 10 orders of magnitude. The study uncovers the complex paths by which disks assemble and demonstrates that magnetic fields play a central role in their formation and early evolution.

The interstellar medium (ISM), the site of star formation in galaxies, is a very complex environment. Diffuse hot regions (with temperatures of several million Kelvin) often exist in close proximity to cold, dense molecular clouds (with temperatures below a few hundred Kelvin). ‘Stellar feedback’, e.g. the explosion of massive stars as supernovae, creates the hot gas and drives turbulent gas motion in the ISM. This turbulence also causes cooling and can lead to gravitational collapse in certain regions, which form molecular clouds. Stars and their proto-stellar disks form in these molecular clouds from dense cores.

This process covers a large range of spatial scales: using the distance between earth and sun, an ‘astronomical unit’ or AU, as a ruler, the scales range from several 10 million AU for the size of molecular clouds, to a million AU large ‘bubbles’ created by supernovae, to regions smaller than a per cent of an AU for a newly forming proto-star. Specific numerical techniques are required to simulate such a system, as using equally high resolution everywhere would overwhelm even supercomputers. Most previous studies of disk formation simplify the problem and focus on the final disk formation phase after the collapse of dense cloud cores with uniform densities and turbulent velocities imposed by hand. This, however, misses the self-consistent formation of the cloud core structure, kinematics, and magnetic fields from its the large-scale environment.

How important are magnetic fields in this picture? It is well established observationally that clouds cores are strongly magnetized, which impacts their evolution. ‘Ideal’ magneto-hydrodynamical (MHD) models assume that magnetic fields are carried along with the gas. They back-react on the gas through the Lorentz force and provide support against gravitational collapse. The Lorentz force also works against the rotational twisting of magnetic field lines - a situation encountered where a rotating disk surrounds a young star. This resistance slows down gas so much that it falls onto the star, while fast-rotating material leaves the system in a proto-stellar wind - leaving no disks behind. However, extended proto-stellar disks are regularly observed around young stars (Figure 1) – inconsistent with ‘ideal’ MHD models.

This problem can be solved with more realistic ‘non-ideal’ MHD models where neutral and ionized particles move differently (ambipolar diffusion).

With this process, magnetic fields in collapsing cores are reduced and proto-stellar disks are able to form. Numerical simulations of this process are expensive but essential to understand proto-stellar disk formation.

In a project supported by the DFG Excellence Cluster ‘ORIGINS’ researchers from the Max Planck Institute for Astrophysics (MPA,), the Max Planck Institute for Extraterrestrial Physics (MPE,), Harvard, and the University of Cologne performed high-resolution non-ideal MHD ‘zoom’ simulations to self-consistently follow proto-stellar disk formation from their parent turbulent, multi-phase molecular clouds down to stellar sub-AU scales. The unprecedented ‘non-ideal’ MHD simulations span over 10 orders of magnitude in spatial scales.

In this setup with a realistic large-scale turbulent environment (Figure 2), no extended proto-stellar disks can form with ‘ideal’ MHD, while ‘non-ideal’ MHD allows for the early formation of a disk, similar to what is seen in the ‘hydro’ model without any magnetic field (Figure 3). However, the substructures of the disks formed in these different models are clearly distinct from each other. The study indicates that magnetic fields, along with non-ideal MHD effects, and the large-scale, multi-phase and turbulent environment play a central role for proto-stellar disk formation.

Ongoing work building on this study will focus on the evolution of these disks formed in realistic environments over a longer time-span. This will also allow the researchers to study how early stellar companions form.



Authors:

Alexander Mayer
PhD student
Tel: 2042
amayer@mpa-garching.mpg.de

Thorsten Naab
Scientific Staff
tnaab@mpa-garching.mpg.de


Original publication

 Mayer, Alexander C.; Naab, Thorsten; Caselli, Paola; et al.
Protostellar discs in their natural habitat ─ the formation of protostars and their accretion discs in the turbulent and magnetized interstellar medium
Monthly Notices of the Royal Astronomical Society, Volume 543, Issue 4, pp. 3321-3344, 24 pp.

DOI

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