It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, July 22, 2025
SPACE/COSMOS
370-million mile Hail Mary saves camera aboard NASA’s Jupiter orbiter
An experimental technique rescued a camera aboard the agency’s Juno spacecraft, offering lessons that will benefit other space systems that experience high radiation
SAN ANTONIO — July 22, 2025 —The Southwest Research Institute-led mission team of NASA’s Jupiter-orbiting Juno spacecraft executed a deep-space move in December 2023 to repair its JunoCam imager to capture photos of the Jovian moon Io. Results from the long-distance save were presented during a technical session on Wednesday, July 16, at the Institute of Electrical and Electronics Engineers Nuclear & Space Radiation Effects Conference in Nashville.
JunoCam is a color, visible-light camera. It was included on the spacecraft to engage the public with a citizen science program, but its images have led the way to several important scientific discoveries as well. The optical unit for the camera is located outside a titanium-walled radiation vault, which protects sensitive electronic components for many of Juno’s engineering and science instruments.
This is a challenging location because Juno’s travels carry it through the most intense planetary radiation fields in the solar system. While mission designers were confident JunoCam could operate through the first eight orbits of Jupiter, no one knew how far the instrument would last after that.
Throughout Juno’s first 34 orbits (its prime mission), JunoCam operated near flawlessly, returning images that the team routinely incorporated into Juno’s science papers. Then, during its 47th orbit, the imager began showing hints of radiation damage. By orbit 56, nearly all the images were corrupted.
Long Distance Microscopic Repair
While the team knew the issue may be tied to radiation, pinpointing what, specifically, was damaged within JunoCam was difficult from hundreds of millions of miles away. Clues pointed to a damaged voltage regulator that is vital to JunoCam’s power supply. With few options for recovery, the team turned to a process called annealing, where a material is heated for a specified period before slowly cooling. Although the process is not well understood, the idea is that the heating can reduce defects in the material.
“The Juno team knew annealing can sometimes alter a material like silicon at a microscopic level but didn’t know if this would fix the damage,” said JunoCam imaging engineer Jacob Schaffner of Malin Space Science Systems in San Diego, which designed and developed JunoCam and is part of the team that operates it. “We commanded JunoCam’s one heater to raise the camera’s temperature to 77 degrees Fahrenheit (25 degrees Celsius) — much warmer than typical for JunoCam — and waited with bated breath to see the results.”
Soon after the annealing process finished, JunoCam began cranking out crisp images for the next several orbits. But Juno was flying deeper and deeper into the heart of Jupiter’s radiation fields with each pass. By orbit 55, the imagery had again begun showing problems.
Hail Mary Time
“After orbit 55, our images were full of streaks and noise,” said JunoCam instrument lead Michael Ravine of Malin Space Science Systems. “We tried different schemes for processing the images to improve the quality, but nothing worked. With the close encounter of Io bearing down on us in a few weeks, it was Hail Mary time: The only thing left we hadn’t tried was to crank JunoCam’s heater all the way up and see if more extreme annealing would save us.”
Test images sent back to Earth during the annealing showed little improvement the first week. Then, with the close approach of Io only days away, the images began to improve dramatically. By the time Juno came within 930 miles (1,500 kilometers) of the volcanic moon’s surface on Dec. 30, 2023, the images were almost as good as the day the camera launched, capturing detailed views of Io’s north polar region that revealed mountain blocks covered in sulfur dioxide frosts rising sharply from the plains and previously uncharted volcanos with extensive flow fields of lava.
Testing Limits
To date, the solar-powered spacecraft has orbited Jupiter 74 times. Recently, the image noise returned during Juno’s 74th orbit. The team plans to continue experimenting with annealing with the hope that the camera will again provide quality images.
Since first experimenting with JunoCam, the Juno team has applied derivations of this annealing technique on several Juno instruments and engineering subsystems. The lessons learned are exceeding the mission’s expectations.
“Juno is teaching us how to create and maintain spacecraft tolerant to radiation, providing key insights that will benefit not only Juno, but satellites in orbit around Earth,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “I expect the lessons learned from Juno will be applicable to both defense and commercial satellites as well as other NASA missions.”
More About Juno
NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. The Italian Space Agency, Agenzia Spaziale Italiana, funded the Jovian InfraRed Auroral Mapper. Lockheed Martin Space in Denver built and operates the spacecraft. Various other institutions around the U.S. provided several of the other scientific instruments on Juno.
The image to the left, taken with ESO’s Very Large Telescope (VLT), shows a possible planet being born around the young star HD 135344B. This star, located around 440 light-years away, is surrounded by a disc of dust and gas with prominent spiral arms. Theory predicts that planets can sculpt spiral arms like these, and the new planet candidate is located at the base of one of the arms, just as expected.
The image was captured with a new VLT instrument: the Enhanced Resolution Imager and Spectrograph (ERIS). The central black circle corresponds to a coronagraph –– a device that blocks the light of the star to reveal faint details around it. The white circle indicates the location of the planet.
The image to the right is a combination of previous observations taken with the SPHERE instrument also at the VLT (red) and the Atacama Large Millimeter/submillimeter Array (ALMA, orange and blue). These and other previous studies of HD 135344B did not find signatures of a companion, but ERIS may have finally unveiled the culprit responsible for the star’s spiral disc.
Credit: ESO/F. Maio et al./T. Stolker et al./ ALMA (ESO/NAOJ/NRAO)/N. van der Marel et al.
Astronomers may have caught a still-forming planet in action, carving out an intricate pattern in the gas and dust that surrounds its young host star. Using ESO’s Very Large Telescope (VLT), they observed a planetary disc with prominent spiral arms, finding clear signs of a planet nestled in its inner regions. This is the first time astronomers have detected a planet candidate embedded inside a disc spiral.
“We will never witness the formation of Earth, but here, around a young star 440 light-years away, we may be watching a planet come into existence in real time,” says Francesco Maio, a doctoral researcher at the University of Florence, Italy, and lead author of this study, published today in Astronomy & Astrophysics.
The potential planet-in-the-making was detected around the star HD 135344B, within a disc of gas and dust around it called a protoplanetary disc. The budding planet is estimated to be twice the size of Jupiter and as far from its host star as Neptune is from the Sun. It has been observed shaping its surroundings within the protoplanetary disc as it grows into a fully formed planet.
Protoplanetary discs have been observed around other young stars, and they often display intricate patterns, such as rings, gaps or spirals. Astronomers have long predicted that these structures are caused by baby planets, which sweep up material as they orbit around their parent star. But, until now, they had not caught one of these planetary sculptors in the act.
In the case of HD 135344B’s disc, swirling spiral arms had previously been detected by another team of astronomers using SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch), an instrument on ESO’s VLT. However, none of the previous observations of this system found proof of a planet forming within the disc.
Now, with observations from the new VLT’s Enhanced Resolution Imager and Spectrograph (ERIS) instrument, the researchers say they may have found their prime suspect. The team spotted the planet candidate right at the base of one of the disc’s spiral arms, exactly where theory had predicted they might find the planet responsible for carving such a pattern.
“What makes this detection potentially a turning point is that, unlike many previous observations, we are able to directly detect the signal of the protoplanet, which is still highly embedded in the disc,” says Maio, who is based at the Arcetri Astrophysical Observatory, a centre of Italy’s National Institute for Astrophysics (INAF). “This gives us a much higher level of confidence in the planet’s existence, as we’re observing the planet’s own light.”
A star’s companion is born
A different team of astronomers have also recently used the ERIS instrument to observe another star, V960 Mon, one that is still in the very early stages of its life. In a study published on 18 July in The Astrophysical Journal Letters, the team report that they have found a companion object to this young star. The exact nature of this object remains a mystery.
The new study, led by Anuroop Dasgupta, a doctoral researcher at ESO and at the Diego Portales University in Chile, follows up observations of V960 Mon made a couple of years ago. Those observations, made with both SPHERE and the Atacama Large Millimeter/submillimeter Array (ALMA), revealed that the material orbiting V960 Mon is shaped into a series of intricate spiral arms. They also showed that the material is fragmenting, in a process known as ‘gravitational instability’, when large clumps of the material around a star contract and collapse, each with the potential to form a planet or a larger object.
“That work revealed unstable material but left open the question of what happens next. With ERIS, we set out to find any compact, luminous fragments signalling the presence of a companion in the disc — and we did,” says Dasgupta. The team found a potential companion object very near to one of the spiral arms observed with SPHERE and ALMA. The team say that this object could either be a planet in formation, or a ‘brown dwarf’ — an object bigger than a planet that didn’t gain enough mass to shine as a star.
If confirmed, this companion object may be the first clear detection of a planet or brown dwarf forming by gravitational instability.
More information
This research highlighted in the first part of this release was presented in the paper “Unveiling a protoplanet candidate embedded in the HD 135344B disk with VLT/ERIS” to appear in Astronomy & Astrophysics (doi: 10.1051/0004-6361/202554472). The second part of the release highlights the study “VLT/ERIS observations of the V960 Mon system: a dust-embedded substellar object formed by gravitational instability?” published in The Astrophysical Journal Letters (doi: 10.3847/2041-8213/ade996).
The team who conducted the first study (on HD 135344B) is composed of F. Maio (University of Firenze, Italy, and INAF-Osservatorio Astrofisico Arcetri, Firenze, Italy [OAA]), D. Fedele (OAA), V. Roccatagliata (University of Bologna, Italy [UBologna] and OAA), S. Facchini (University of Milan, Italy [UNIMI]), G. Lodato (UNIMI), S. Desidera (INAF-Osservatorio Astronomico di Padova, Italy [OAP]), A. Garufi (INAF - Istituto di Radioastronomia, Bologna, Italy [INAP-Bologna], and Max-Planck-Institut für Astronomie, Heidelberg, Germany [MPA]), D. Mesa (OAP), A. Ruzza (UNIMI), C. Toci (European Southern Observatory [ESO], Garching bei Munchen, Germany, and OAA), L. Testi (OAA, and UBologna), A. Zurlo (Diego Portales University [UDP], Santiago, Chile, and Millennium Nucleus on Young Exoplanets and their Moons [YEMS], Santiago, Chile), and G. Rosotti (UNIMI).
The team behind the second study (on V960 Mon) is primarily composed of members of the Millennium Nucleus on Young Exoplanets and their Moons (YEMS), a collaborative research initiative based in Chile. Core YEMS contributors include A. Dasgupta (ESO, Santiago, Chile, UDP, and YEMS), A. Zurlo (UDP and YEMS), P. Weber (University of Santiago [Usach], Chile, and YEMS, and Center for Interdisciplinary Research in Astrophysics and Space Exploration [CIRAS], Santiago, Chile), F. Maio (OAA, and University of Firenze, Italy), Lucas A. Cieza (UDP and YEMS), D. Fedele (OAA), A. Garufi (INAF Bologna and MPA), J. Miley (Usach, YEMS, and CIRAS), P. Pathak (Indian Institute of Technology, Kanpur, India), S. Pérez (Usach and YEMS, and CIRAS), and V. Roccatagliata (UBologna and OAA).
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of 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.
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 Cherenkov Telescope Array South, 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.
Using the NASA-NSF-funded ‘Alopeke instrument on the Gemini North telescope, one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation (NSF) and operated by NSF NOIRLab, astronomers have discovered a companion star in an incredibly tight orbit around Betelgeuse. This discovery answers the millennia-old question of why this famous star experiences a roughly six-year-long periodic change in its brightness, and provides insight into the physical mechanisms behind other variable red supergiants. The companion star appears blue here because, based on the team’s analysis, it is likely an A- or B-type star, both of which are blue-white due to their high temperatures.
‘Alopeke is funded by the NASA-NSF Exoplanet Observational Research Program (NN-EXPLORE).
Credit: International Gemini Observatory/NOIRLab/NSF/AURA Image Processing: M. Zamani (NSF NOIRLab)
Betelgeuse is one of the brightest stars in the night sky, and the closest red supergiant to Earth. It has an enormous volume, spanning a radius around 700 times that of the Sun. Despite only being ten million years old, which is considered young by astronomy standards, it’s late in its life. Located in the shoulder of the constellation Orion, people have observed Betelgeuse with the naked eye for millennia, noticing that the star changes in brightness over time. Astronomers established that Betelgeuse has a main period of variability of around 400 days and a more extended secondary period of around six years.
In 2019 and 2020, there was a steep decrease in Betelgeuse’s brightness — an event referred to as the ‘Great Dimming.’ The event led some to believe that a supernova death was quickly approaching, but scientists were able to determine the dimming was actually caused by a large cloud of dust ejected from Betelgeuse.
The Great Dimming mystery was solved, but the event sparked a renewed interest in studying Betelgeuse, which brought about new analyses of archival data on the star. One analysis led scientists to propose that the cause of Betelgeuse’s six-year variability is the presence of a companion star [1]. But when the Hubble Space Telescope and the Chandra X-Ray Observatory searched for this companion, no detections were made.
The companion star has now been detected for the first time by a team of astrophysicists led by Steve Howell, a senior research scientist at NASA Ames Research Center. They observed Betelgeuse using a speckle imager called ‘Alopeke. ‘Alopeke, which means ‘fox’ in Hawaiian, is funded by the NASA–NSF Exoplanet Observational Research Program (NN-EXPLORE) and is mounted on the Gemini North telescope, one half of the International Gemini Observatory, funded in part by the U.S. National Science Foundation and operated by NSF NOIRLab.
Speckle imaging is an astronomical imaging technique that uses very short exposure times to freeze out the distortions in images caused by Earth’s atmosphere. This technique enables high resolution, which, when combined with the light collecting power of Gemini North’s 8.1-meter mirror, allowed for Betelgeuse’s faint companion to be directly detected.
Analysis of the companion star’s light allowed Howell and his team to determine the companion star’s characteristics. They found that it is six magnitudes fainter than Betelgeuse in the optical wavelength range, it has an estimated mass of around 1.5 times that of the Sun, and it appears to be an A- or B-typepre-main-sequence star — a hot, young, blue-white star that has not yet initiated hydrogen burning in its core.
The companion is at a relatively close distance away from the surface of Betelgeuse — about four times the distance between the Earth and the Sun. This discovery is the first time a close-in stellar companion has been detected orbiting a supergiant star. Even more impressive — the companion orbits well within Betelgeuse’s outer extended atmosphere, proving the incredible resolving abilities of ‘Alopeke.
“Gemini North’s ability to obtain high angular resolutions and sharp contrasts allowed the companion of Betelgeuse to be directly detected,” says Howell. Furthermore, he explains that ‘Alopeke did what no other telescope has done before: “Papers that predicted Betelgeuse’s companion believed that no one would likely ever be able to image it.”
This discovery provides a clearer picture of this red supergiant’s life and future death. Betelgeuse and its companion star were likely born at the same time. However, the companion star will have a shortened lifespan as strong tidal forces will cause it to spiral into Betelgeuse and meet its demise, which scientists estimate will occur within the next 10,000 years.
The discovery also helps to explain why similar red supergiant stars might undergo periodic changes in their brightness on the scale of many years. Howell shares his hope for further studies in this area: “This detection was at the very extremes of what can be accomplished with Gemini in terms of high-angular resolution imaging, and it worked. This now opens the door for other observational pursuits of a similar nature.”
Martin Still, NSF program director for the International Gemini Observatory adds: “The speckle capabilities provided by the International Gemini Observatory continue to be a spectacular tool, open to all astronomers for a wide range of astronomy applications. Delivering the solution to the Betelgeuse problem that has stood for hundreds of years will stand as an evocative highlight achievement.”
Another opportunity to study Betelgeuse’s stellar companion will occur in November 2027 when it returns to its furthest separation from Betelgeuse, and thus easiest to detect. Howell and his team look forward to observations of Betelgeuse before and during this event to better constrain the nature of the companion.
Notes
[1] Two papers released in 2024 used decades of observations of Betelgeuse from many observers around the world to predict the orbit and location of the companion star (see DOI: 10.3847/1538-4357/ad93c8 and DOI: 10.3847/1538-4357/ad87f4).
More information
This research was presented in a paper titled “Probable Direct Imaging Discovery of the Stellar Companion to Betelgeuse” to appear in The Astrophysical Journal Letters. DOI: 10.3847/2041-8213/adeaaf
The team is composed of Steve B. Howell (NASA Ames Research Center), David R. Ciardi (NASA Exoplanet Science Institute-Caltech/IPAC), Catherine A. Clark (NASA Exoplanet Science Institute-Caltech/IPAC), Douglas A. Hope (Georgia Tech Research Institute, Georgia State University), Colin Littlefield (NASA Ames Research Center, Bay Area Environmental Research Institute), Elise Furlan (NASA Exoplanet Science Institute-Caltech/IPAC).
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.
The NASA–NSF Exoplanet Observational Research Program (NN-EXPLORE) is a joint initiative to advance U.S. exoplanet science by providing the community with access to cutting-edge, ground-based observational facilities. Managed by NASA’s Exoplanet Exploration Program (ExEP), NN-EXPLORE supports and enhances the scientific return of space missions such as Kepler, TESS, HST, and JWST by enabling essential follow-up observations from the ground—creating strong synergies between space-based discoveries and ground-based characterization. ExEP is located at the Jet Propulsion Laboratory. More information at https://exoplanets.nasa.gov/exep/NNExplore/overview/.
Using the NASA-NSF-funded ‘Alopeke instrument on the Gemini North telescope, one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation (NSF) and operated by NSF NOIRLab, astronomers have discovered a companion star in an incredibly tight orbit around Betelgeuse. This discovery answers the millennia-old question of why this famous star experiences a roughly six-year-long periodic change in its brightness, and provides insight into the physical mechanisms behind other variable red supergiants. The companion star appears blue here because, based on the team’s analysis, it is likely an A- or B-type star, both of which are blue-white due to their high temperatures.
‘Alopeke is funded by the NASA-NSF Exoplanet Observational Research Program (NN-EXPLORE).
Credit
International Gemini Observatory/NOIRLab/NSF/AURA Image Processing: M. Zamani (NSF NOIRLab)
Using the NASA-NSF-funded ‘Alopeke instrument on the Gemini North telescope, one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation (NSF) and operated by NSF NOIRLab, astronomers have discovered a companion star in an incredibly tight orbit around Betelgeuse. This discovery answers the millennia-old question of why this famous star experiences a roughly six-year-long periodic change in its brightness, and provides insight into the physical mechanisms behind other variable red supergiants. The companion star appears blue here because, based on the team’s analysis, it is likely an A- or B-type star, both of which are blue-white due to their high temperatures.
‘Alopeke is funded by the NASA-NSF Exoplanet Observational Research Program (NN-EXPLORE).
Credit
International Gemini Observatory/NOIRLab/NSF/AURA Image Processing: M. Zamani (NSF NOIRLab)
This image depicts the X-ray emission intensity distribution (keyed in colors) calculated by the proposed model and Earth’s magnetic field (lines). The sphere in the center of the figure represents the Earth, and the left-hand side of the figure is the sun side.
Credit: Dr. Yosuke Matsumoto from Chiba University, Japan
The magnetosphere, formed by the Earth’s magnetic field, acts as a protective shield that deflects solar wind—the flow of charged particles constantly streaming from the Sun toward our planet. This magnetic barrier protects our atmosphere and the technology we increasingly depend on in the near-Earth space, such as communication satellites. However, the magnetosphere isn’t impenetrable, as a fundamental process called ‘magnetic reconnection’ can temporarily strip this barrier during intense solar wind and cause violent energy fluctuations in the near-Earth space. As human activity in this region increases, understanding and forecasting such space weather becomes critical.
A key to understanding these breaches lies in measuring what’s known as the ‘reconnection rate,’ which quantifies energy efficiency in magnetic reconnection processes. For decades, scientists have attempted to measure this rate using various methods, including spacecraft flying directly through reconnection zones and observations of solar flares by remote imaging. However, these traditional approaches provide only local snapshots of the magnetic reconnection process or are limited by specific, often unsteady conditions. Obtaining a comprehensive and consistent picture that bridges the gap between local and global reconnection rates remains a challenge.
Against this backdrop, a research team led by Associate Professor Yosuke Matsumoto from the Institute for Advanced Academic Research at Chiba University, Japan, is testing an innovative approach using soft X-ray imaging to measure the reconnection rates. The study, co-authored by Mr. Ryota Momose from Chiba University and Prof. Yoshizumi Miyoshi from Nagoya University, was made available online on June 23, 2025, and was published in Volume 52, Issue 12 of the journal Geophysical Research Letters on June 28, 2025.
Soft X-ray emission occurs through a charge exchange process between the heavy ions in the solar wind and the hydrogen neutral atoms originating from the Earth. In this study, the researchers propose leveraging the soft X-rays that are naturally emitted when solar wind particles interact with the boundaries of the magnetosphere to remotely measure reconnection rates across much larger regions than previously possible.
The team conducted advanced computer simulations on the Fugaku supercomputer, combining high-resolution global magnetohydrodynamic simulations of Earth’s magnetosphere with a model of soft X-ray emission. From the simulations, they analyzed how reconnection-related X-rays can be viewed from a satellite positioned at a lunar distance during intense solar wind conditions. This vantage point roughly matches that of an upcoming X-ray imaging satellite like GEO-X, which is scheduled for launch in the near future.
After analyzing the simulation results, the researchers found that the brightest X-ray emissions form distinct cusp-shaped patterns that directly reflect the magnetic field structure around reconnection zones. By measuring the opening angle of these bright regions, they calculated the global reconnection rate to have a value of 0.13, which closely matches theoretical predictions and previous laboratory measurements. Therefore, the results demonstrate that the geometry of bright X-ray features correlates with the reconnection rate, offering a new method to estimate this important parameter. “Imaging X-rays from the sun-facing magnetospheric boundary can now potentially quantify solar wind energy inflow into the magnetosphere, making X-rays a novel space weather diagnostic tool,” highlights Dr. Matsumoto.
By providing a new way to measure and understand magnetic reconnection, this research contributes directly to improving space weather forecasting. Being able to predict how solar activity influences the near-Earth space is vital for protecting astronauts and ensuring the reliability of communication systems and space missions, especially in the face of potentially devastating events like magnetic storms.
Notably, this study also has broader scientific implications for understanding magnetic reconnection in other contexts, as Dr. Matsumoto explains, “Magnetic reconnection is not only responsible for breaching Earth’s magnetic shield but is also the underlying process behind explosive events in plasma devices, the Sun, and black holes. Understanding this process is essential for advancing technologies like plasma confinement in fusion reactors and investigating the origin of high-energy cosmic rays.”
As humanity prepares for an era of space exploration and commercial space activities, this newly proposed method could pave the way to accurate space weather predictions, helping ensure the safety and success of our ventures beyond Earth’s atmosphere.
About Associate Professor Yosuke Matsumoto from Chiba University Dr. Yosuke Matsumoto joined Chiba University in 2011. Since 2022, he has been serving as an Associate Professor at the Institute for Advanced Academic Research. He specializes in space and planetary science, as well as theoretical studies related to cosmic rays and astrophysics. He has published over 70 research papers on these topics and received multiple awards, including the NASA Group Achievement Award to the MAVEN Mission Team. He has professional memberships in multiple academic societies, including the Society of Geomagnetism and Earth, Planetary and Space Sciences.
Illustration of the planetary system of L 98-59: five small exoplanets orbit closely around this red dwarf star, located 35 light-years away. In the foreground is the habitable-zone super-Earth L 98-59 f, whose existence was confirmed in this study.
A team led by the Trottier Institute for Research on Exoplanets (IREx) has achieved the most precise study to date of the L 98-59 planetary system, and confirmed the existence of a fifth planet in the star’s habitable zone, where conditions could allow liquid water to exist.
Volcanic planets, a sub-Earth, and a water world
L 98-59, a small red dwarf located just 35 light-years from Earth, hosts three small transiting exoplanets discovered in 2019, thanks to NASA's TESS space telescope, and a fourth planet revealed through radial velocity measurements with the European Southern Observatory's ESPRESSO spectrograph. All four planets orbit their parent star in a compact orbital configuration, all at distances five times closer than Mercury is to the Sun.
By carefully reanalyzing a rich set of observations from ground-based and space-based telescopes, a team led by Université de Montréal and Trottier Institute for Research on Exoplanets (IREx) researcher Charles Cadieux has determined the planets’ sizes and masses with unprecedented precision.
“These new results paint the most complete picture we’ve ever had of the fascinating L 98-59 system,” said Cadieux. “It’s a powerful demonstration of what we can achieve by combining data from space telescopes and high-precision instruments on Earth, and it gives us key targets for future atmospheric studies with the James Webb Space Telescope [JWST].”
All planets in the system have masses and sizes compatible with the terrestrial regime. The innermost planet, L 98-59 b, is only 84% of Earth’s size and about half its mass, making it one of the rare sub-Earths known with well-measured parameters.
The two inner planets may experience extreme volcanic activity due to tidal heating, similar to Jupiter’s volcanic Moon, Io, in the Solar System. Meanwhile, the third, unusually low in density, may be a “water world,” a planet enriched in water unlike anything in our Solar System.
The refined measurements reveal nearly perfectly circular orbits for the inner planets, a favourable configuration for future atmospheric detections.
“With its diversity of rocky worlds and range of planetary compositions, L 98-59 offers a unique laboratory to address some of the field’s most pressing questions: What are super-Earths and sub-Neptunes made of? Do planets form differently around small stars? Can rocky planets around red dwarfs retain atmospheres over time?” adds René Doyon, co-author of the study, who is a professor at UdeM and the Director of IREx.
A fifth planet in the habitable zone
One of the key breakthroughs of this study is the confirmation of a fifth planet in the L 98-59 system. This planet, designated L 98-59 f, does not transit its host star — meaning it doesn’t pass directly between us and the star — but its presence was revealed through subtle variations in the star’s motion, detected using radial velocity measurements from HARPS (High Accuracy Radial velocity Planet Searcher) and ESPRESSO data.
L 98-59 f receives about the same amount of stellar energy as Earth does from the Sun, placing it firmly within the temperate, or habitable zone, a region where water could remain in liquid form.
“Finding a temperate planet in such a compact system makes this discovery particularly exciting,” said Cadieux. “It highlights the remarkable diversity of exoplanetary systems and strengthens the case for studying potentially habitable worlds around low-mass stars.”
Unlocking new insights with existing observations
Rather than requesting new telescope time, the team made these discoveries by relying on a rich archive of data from NASA’s TESS space telescope, ESO’s HARPS and ESPRESSO spectrographs in Chile, and the JWST.
They employed the novel line-by-line radial velocity analysis technique introduced by IREx researchers in 2022 to improve the precision of the data significantly. By combining it with a new differential temperature indicator also developed by the team, they were able to precisely identify and remove the stellar activity signal from the data, revealing the planetary signal in unprecedented detail.
By combining these enhanced measurements with analysis of transits seen by JWST, the team doubled the precision of mass and radius estimates for the known planets.
“We developed these techniques to unlock this kind of hidden potential in archival data,” adds Étienne Artigau, co-author of the study and researcher at UdeM. “It also highlights how improving analysis tools allow us to improve upon previous discoveries with data that is just waiting to be revisited.”
Next stop: Webb
These results confirm L 98-59 as one of the most compelling nearby systems for exploring the diversity of rocky planets, and, eventually, searching for signs of life.
Its proximity, the small size of its star, and the range of planetary compositions and orbits make it an ideal candidate for atmospheric follow-up with the JWST, which the IREx team has already started.
“With these new results, L 98-59 joins the select group of nearby, compact planetary systems that we hope to understand in greater detail over the coming years,” says Alexandrine L’Heureux, co-author of the study and Ph.D. student at UdeM. “It’s exciting to see it stand alongside systems like TRAPPIST-1 in our quest to unlock the nature and formation of small planets orbiting red dwarf stars.”
About this study
The article “Detailed Architecture of the L 98-59 System and Confirmation of a Fifth Planet in the Habitable Zone” will appear shortly in The Astronomical Journal. The team, led by Charles Cadieux, includes Alexandrine L’Heureux, Caroline Piaulet-Ghorayeb (now at the University of Chicago), René Doyon, Étienne Artigau, Neil J. Cook, Louis-Philippe Coulombe, Pierre-Alexis Roy, David Lafrenière, Pierrot Lamontagne, Michael Radica (now at the University of Chicago), and Björn Benneke of the Trottier Institute for Research on Exoplanets (IREx) at the Université de Montréal. Additional co-authors are Eva-Maria Ahrer (Max Planck Institute for Astronomy, Germany), Drew Weisserman (McMaster University, Canada), and Ryan Cloutier (McMaster University, Canada).
Silicon atoms on a silicon surface organize in pairs that can assume two different positions like a seesaw. The interaction between the seesaws leads to long-range and direction-dependent order. In analogy to the early universe, the size of the ordered domains depends on the cooling rate of the surface.
Solar cells and computer chips need silicon layers that are as perfect as possible. Every imperfection in the crystalline structure of a silicon wafer increases the risk of reduced efficiency or defective switching processes. If you know how silicon atoms arrange themselves to form a crystal lattice on a thin surface, you gain fundamental insights into controlling crystal growth. To this end, a research team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the University of Duisburg-Essen and the Canadian University of Alberta analyzed the behavior of silicon that was flash-frozen. The results show that the speed of cooling has a major impact on the structure of silicon surfaces (DOI: 10.1103/rmc4-xqb3). The underlying mechanism may also have occurred during phase transitions in the early universe shortly after the Big Bang.
At low temperatures, pairs of silicon atoms known as dimers are formed on the surface of the silicon which can tilt to the right or left like a seesaw. Above a certain critical temperature – in the case of silicon 190 Kelvin (−83 °C) – the dimers rock backwards and forwards between the two states. “When they are cooled below the critical temperature, the dimers lock into one of the two states,” says Dr. Gernot Schaller, Head of Quantum Information Technology at HZDR’s Institute of Theoretical Physics. “They are effectively frozen by this phase transition.”
Moreover, the individual dimers influence each other. This influence is dependent on the arrangement of the dimers: the coupling in the transverse direction is stronger than in the longitudinal. “And it is precisely this strong so-called anisotropy that is essentially responsible for the dimers’ behavior on the surface,” says Schaller. “Depending on the cooling rate we see a transition from one-dimensional behavior to two-dimensional.” One-dimensional means that when the cooling is extremely fast, more than 100 Kelvin per microsecond, the dimers’ tilt angles arrange themselves along long chains. If the temperature drops more slowly, however, two-dimensional behavior prevails. In this case the silicon dimers form more or less large, ordered surfaces, known as domains, characterized by a uniform honeycomb structure. “And the slower the cooling, the larger the domains,” explains Schaller.
To calculate the crystal surface structure the researchers employed the so-called Ising model. This mathematical model considers the silicon dimers’ tilt angles which can only assume one of two possible states. This elegant description of a phase transition during the rapid cool-down of silicon surfaces thanks to the anisotropic Ising model is not just pure theory. The researchers also compared their analytical and numerical calculations with experimental data.
Honeycomb and zigzag chains
High-resolution scanning tunnel microscope images of flash-frozen silicon surfaces reveal structures that correspond to the simulations. Both extended two-dimensional honeycomb structures and sharp one-dimensional boundaries between zigzag-shaped chains can be seen. “And our colleagues at the University of Duisburg-Essen are planning further experiments that could confirm the impact of the cooling rate on the structure of the silicon surface – in analogy to our simulations,” says Prof. Ralf Schützhold, director of HZDR’s Institute of Theoretical Physics.
The results not only generate new ideas for the tailored manufacture of defect-free silicon surfaces, “the way the silicon dimers behave exhibits parallels with the so-called Kibble-Zurek mechanism,” says Schützhold. Named after the theoretical physicists, Tom Kibble and Wojciech H. Zurek, this theoretical model describes how topological defects, that is, imperfections in an ordered structure, are formed during fast phase transitions. Kibble looked at processes during the cooling of the very young universe following the Big Bang. Topological defects, such as point-like monopoles or linear defects – the cosmic strings – could have been created in this way. Zurek predicted analogous behavior in condensed matter using the example of cryogenic superfluid helium. And now the team around Schaller and Schützhold has shown that the Kibble-Zurek mechanism is apparently much more widespread than originally expected and can even occur on flash-frozen silicon surfaces.
Publication: G. Schaller, F. Queisser, S. P. Katoorani, C. Brand, C. Kohlfürst, M. R. Freeman, A. Hucht, P. Kratzer, B. Sothmann, M. Horn-von Hoegen, R. Schützhold, Kibble-Zurek Dynamics in the Anisotropic Ising Model of the Si(001) Surface, in Physical Review Letters, 2025 (DOI: 10.1103/rmc4-xqb3).
Further information: Dr. Gernot Schaller | Head of Quantum Information Technology Institute of Theoretical Physics at HZDR Phone: +49 351 260 3307 | Email: g.schaller@hzdr.de
Media contact: Simon Schmitt | Head Communications and Media Relations at HZDR Phone: +49 351 260 3400 | Mob.: +49 175 874 2865 | Email: s.schmitt@hzdr.de
The Helmholtz-Zentrum Dresden-Rossendorf (HZDR) performs – as an independent German research center – research in the fields of energy, health, and matter. We focus on answering the following questions:
How can energy and resources be utilized in an efficient, safe, and sustainable way?
How can malignant tumors be more precisely visualized, characterized, and more effectively treated?
How do matter and materials behave under the influence of strong fields and in smallest dimensions?
To help answer these research questions, HZDR operates large-scale facilities, which are also used by visiting researchers: the Ion Beam Center, the Dresden High Magnetic Field Laboratory and the ELBE Center for High-Power Radiation Sources. HZDR is a member of the Helmholtz Association and has six sites (Dresden, Freiberg, Görlitz, Grenoble, Leipzig, Schenefeld near Hamburg) with almost 1,500 members of staff, of whom about 680 are scientists, including 200 Ph.D. candidates.
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