Using data from NASA’s Chandra X-ray Observatory, astronomers may have found a supernova remnant in an intriguing neighborhood in the middle of our galaxy. A paper describing these new findings published in The Astrophysical Journal.

Supernova remnants are the expanding remains of exploded stars and provide elements – like iron, oxygen, and silicon – that are critical for the formation of planets and for life as we know it to form and flourish.

This new supernova remnant, if confirmed, would be one of the closest ever discovered to the supermassive black hole at the central region of the Milky Way galaxy, an exotic region crammed with massive stars, long threads of magnetic fields and dense clouds of gas orbiting rapidly around the Galactic Center.

A new composite image of this region contains X-rays from Chandra and ESA’s (European Space Agency’s) XMM-Newton mission (shown in blue) as well as radio data from the MeerKAT telescope (shown in red) in South Africa. These have been combined with an optical image from the Pan-STARRS telescopes in Hawaii (red, green, and blue). The plane of the galaxy runs horizontally from left to right in the image, and the central black hole is off to the left of the image.

The evidence for the new supernova remnant, located about 26,000 light-years from Earth, comes from X-ray data from Chandra and XMM-Newton. The X-ray data reveals a “blob” of X-ray emission that may come from the remains of a massive star that self-destructed as a supernova, buried within the larger cloud of expanding gas.

The location of this suspected supernova remnant in the image is labeled with a circle.

It is in a bubble of gas that has had electrons stripped away from hydrogen – called an “H II region” – surrounding a massive, young star. This bubble is a bright source of radio emission called Sagittarius C.

If this is indeed a supernova remnant, then it is expanding at about two million miles per hour and is at least about 1,700 years old. Previously, observations with NASA’s now-retired SOFIA (Stratospheric Observatory for Infrared Astronomy) mission had shown evidence for an expanding shell of gas surrounding Sagittarius C. This gave astronomers a hint that a stellar explosion had occurred in the same spot.

The long filaments seen in the radio image are caused by energetic particles travelling along magnetic fields that are mostly directed perpendicular to the plane of the galaxy.

The nuclear fusion engines of stars create elements from hydrogen and helium that were abundant at the beginning of the universe. When stars explode at the end of their lives as supernovae, they send these newly synthesized elements into interstellar space and provide material for the next generation of stars and planets.

The team of astronomers searched the X-ray data for signs of increased amounts of key elements in the remnant, which would have been caused by the stellar explosion blasting them into space. While they did not see an enhancement, this could imply that the stellar debris has already mixed with the surrounding gas.

An alternative explanation for the X-ray blob is that the hot gas comes from a collection of massive stars in the region. The authors of the recent study don’t think this explanation is likely, because the X-ray emission from the blob is more than ten times brighter than the X-ray emission of large, known stellar clusters with bright, massive stars.

An additional image shows data from NASA’s James Webb Space Telescope added to the X-ray and radio data. The light blue color represents infrared light from gas in the H II region, and the darker blue depicts X-rays from the supernova remnant candidate, on the right side of the image. X-rays near the center of the image are associated with the H II region, possibly caused by material blown away by massive stars that has heated gas to millions of degrees, producing X-rays.

The study’s authors are Zhenlin Zhu and Mark Morris of the University of California, Los Angeles; Gabriele Ponti of Italy’s National Institute for Astrophysics; and Ping Zhou of Nanjing University in China.

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

Visual Description

This release features a composite image of colorful, overlapping clouds, which suggests to astronomers that a supernova remnant may be buried in gas near the center of our Milky Way galaxy.

Set against a backdrop packed with distant stars and other specks of light are two distinct, overlapping clouds. The larger, visually dominant cloud, is red and multifaceted. It has an irregular shape, and features patches of different textures, including pockets that resemble wispy smoke, tangles of faint red veins, and clear streaking lines. This large cloud of expanding gas represents radio data from the MeerKAT telescope in South Africa.

Overlapping with that red cloud is a cloudy blue blob representing X-ray data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. Astronomers suggest that this blue blob of X-ray emissions is the remains of a massive star destroyed by a supernova.

Read more from NASA’s Chandra X-ray Observatory

To learn more about NASA’s Chandra mission, visit:

https://science.nasa.gov/chandra

https://chandra.si.edu

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov

The post NASA’s Chandra Discovers Possible Supernova Remnant in Galactic Center appeared first on NASA Science.

Using data from NASA’s Chandra X-ray Observatory, astronomers may have found a supernova remnant in an intriguing neighborhood in the middle of our galaxy. A paper describing these new findings published in The Astrophysical Journal.

Supernova remnants are the expanding remains of exploded stars and provide elements – like iron, oxygen, and silicon – that are critical for the formation of planets and for life as we know it to form and flourish.

This new supernova remnant, if confirmed, would be one of the closest ever discovered to the supermassive black hole at the central region of the Milky Way galaxy, an exotic region crammed with massive stars, long threads of magnetic fields and dense clouds of gas orbiting rapidly around the Galactic Center.

A new composite image of this region contains X-rays from Chandra and ESA’s (European Space Agency’s) XMM-Newton mission (shown in blue) as well as radio data from the MeerKAT telescope (shown in red) in South Africa. These have been combined with an optical image from the Pan-STARRS telescopes in Hawaii (red, green, and blue). The plane of the galaxy runs horizontally from left to right in the image, and the central black hole is off to the left of the image.

The evidence for the new supernova remnant, located about 26,000 light-years from Earth, comes from X-ray data from Chandra and XMM-Newton. The X-ray data reveals a “blob” of X-ray emission that may come from the remains of a massive star that self-destructed as a supernova, buried within the larger cloud of expanding gas.

The location of this suspected supernova remnant in the image is labeled with a circle.

It is in a bubble of gas that has had electrons stripped away from hydrogen – called an “H II region” – surrounding a massive, young star. This bubble is a bright source of radio emission called Sagittarius C.

If this is indeed a supernova remnant, then it is expanding at about two million miles per hour and is at least about 1,700 years old. Previously, observations with NASA’s now-retired SOFIA (Stratospheric Observatory for Infrared Astronomy) mission had shown evidence for an expanding shell of gas surrounding Sagittarius C. This gave astronomers a hint that a stellar explosion had occurred in the same spot.

The long filaments seen in the radio image are caused by energetic particles travelling along magnetic fields that are mostly directed perpendicular to the plane of the galaxy.

The nuclear fusion engines of stars create elements from hydrogen and helium that were abundant at the beginning of the universe. When stars explode at the end of their lives as supernovae, they send these newly synthesized elements into interstellar space and provide material for the next generation of stars and planets.

The team of astronomers searched the X-ray data for signs of increased amounts of key elements in the remnant, which would have been caused by the stellar explosion blasting them into space. While they did not see an enhancement, this could imply that the stellar debris has already mixed with the surrounding gas.

An alternative explanation for the X-ray blob is that the hot gas comes from a collection of massive stars in the region. The authors of the recent study don’t think this explanation is likely, because the X-ray emission from the blob is more than ten times brighter than the X-ray emission of large, known stellar clusters with bright, massive stars.

An additional image shows data from NASA’s James Webb Space Telescope added to the X-ray and radio data. The light blue color represents infrared light from gas in the H II region, and the darker blue depicts X-rays from the supernova remnant candidate, on the right side of the image. X-rays near the center of the image are associated with the H II region, possibly caused by material blown away by massive stars that has heated gas to millions of degrees, producing X-rays.

The study’s authors are Zhenlin Zhu and Mark Morris of the University of California, Los Angeles; Gabriele Ponti of Italy’s National Institute for Astrophysics; and Ping Zhou of Nanjing University in China.

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

Visual Description

This release features a composite image of colorful, overlapping clouds, which suggests to astronomers that a supernova remnant may be buried in gas near the center of our Milky Way galaxy.

Set against a backdrop packed with distant stars and other specks of light are two distinct, overlapping clouds. The larger, visually dominant cloud, is red and multifaceted. It has an irregular shape, and features patches of different textures, including pockets that resemble wispy smoke, tangles of faint red veins, and clear streaking lines. This large cloud of expanding gas represents radio data from the MeerKAT telescope in South Africa.

Overlapping with that red cloud is a cloudy blue blob representing X-ray data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. Astronomers suggest that this blue blob of X-ray emissions is the remains of a massive star destroyed by a supernova.

Read more from NASA’s Chandra X-ray Observatory

To learn more about NASA’s Chandra mission, visit:

https://science.nasa.gov/chandra

https://chandra.si.edu

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov

A new mathematical breakthrough sheds light on how tiny black holes could emerge from critical states of spacetime. Black holes are often portrayed as cosmic giants, swallowing stars and shaping entire galaxies. But some of the most intriguing black holes predicted by physics could be far smaller than an atom. For decades, scientists have known [...]

A new type of gamma-ray sensor developed by NASA, called AstroPix, will take part in a robotic arm demonstration on the agency’s upcoming Fly Foundational Robots mission, set to launch in late 2027.

Gamma rays are the highest-energy form of light. Scientists observe them coming from events like lightning in Earth’s atmosphere, powerful solar flares from our Sun, and cosmic collisions in distant galaxies. The sensors on the AstroPix technology demonstration are designed to measure gamma rays between 20,000 and 700,000 electron volts. For comparison, visible light’s energy falls between 2 and 3 electron volts.

Current NASA missions, including the Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory, also observe gamma rays, including those with even higher energies.

But for energies between 500,000 to 1 million electron volts, existing detectors are less sensitive. This range is where many powerful explosions called gamma-ray bursts shine the brightest. It’s also where astronomers expect to see the strongest glow from the most massive and distant active galaxies powered by black holes. By stacking AstroPix detectors in future missions, scientists could bridge this gap and improve observations of these cosmic objects to better understand the processes that create and drive them.

“The Fly Foundational Robots spacecraft is also a technology demonstration, so the projects were a good fit for each other,” said Dan Violette, an AstroPix team member and post-doctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We need to thoroughly test AstroPix’s performance before we can use the sensors in future science missions. We’ve flown comparable technologies on a scientific balloon mission, and the current prototype eventually will be part of a sounding rocket payload. Many of those flight opportunities only reach near space, though. It’s not often that technology demonstrations like ours can find a ride into orbit.”

Each AstroPix chip contains four silicon pixel gamma-ray detectors, and each detector incorporates 1,225 pixels. The chips function similarly to the sensors in cell phone cameras.

The AstroPix Satellite Technology dEmonstration Payload, also known as A-STEP, will be hosted within the Fly Foundational Robots mission’s Orbital Replacement Unit, a movable module built by Rocket Lab Robotics. Rocket Lab Robotics also will provide a robotic arm that will pick up and reposition the unit during flight and perform in-orbit operations as part of a robotic servicing demonstration. The A-STEP payload will collect its data following the repositioning. Astro Digital will provide the spacecraft.

The Orbital Replacement Unit was designed to support power and data interfaces for a payload, but the original plan called for the robotic arm to reposition the module without one. As mission development progressed, however, the Fly Foundational Robots team identified an opportunity to further maximize the mission’s value by integrating an additional technology demonstration that could fit within the 11.8-inch (30-centimeter) cube.

“The unit already had the volume, power, and data needed to support the AstroPix team’s design,” said Bo Naasz, senior technical lead, In-space Servicing, Assembly, and Manufacturing in the Space Technology Mission Directorate at NASA Headquarters in Washington. “One of our major goals with Fly Foundational Robots is to demonstrate robotic changeout of payloads in orbit, enabling upgrades or improvements to satellites and space instruments at a fraction of the cost of a full mission. Allowing AstroPix to complete its own technology demonstration in orbit is a bonus.”

The AstroPix team is working to deliver their hardware this September, and it will be integrated into the Fly Foundational Robots payload before final integration onto the spacecraft. The Orbital Replacement Unit will hold the chips and all the associated electronics needed to provide power, and collect and transmit data during flight.

NASA’s Fly Foundational Robots mission is funded through the Space Technology Mission Directorate’s ISAM portfolio, managed at NASA Goddard. Rocket Lab Robotics will supply the mission’s robotic arm system through a NASA Small Business Innovation Research Phase III award. Astro Digital will host the orbital flight test of the arm through NASA’s Flight Opportunities program, managed at NASA’s Armstrong Flight Research Center in Edwards, California. The development of AstroPix was supported by NASA’s Astrophysics Division in the Science Mission Directorate at NASA Headquarters, through the agency’s Astrophysics Research and Analysis Program, and funded through the Nancy Grace Roman Technology Fellowship.

To learn more, visit:

https://go.nasa.gov/3R28tWE

By Jeanette Kazmierczak
Goddard Space Flight Center, Greenbelt, Md.

The post NASA Robotic Tech Demo Will Advance Prototype Gamma-Ray Detectors appeared first on NASA Science.

A new type of gamma-ray sensor developed by NASA, called AstroPix, will take part in a robotic arm demonstration on the agency’s upcoming Fly Foundational Robots mission, set to launch in late 2027.

Gamma rays are the highest-energy form of light. Scientists observe them coming from events like lightning in Earth’s atmosphere, powerful solar flares from our Sun, and cosmic collisions in distant galaxies. The sensors on the AstroPix technology demonstration are designed to measure gamma rays between 20,000 and 700,000 electron volts. For comparison, visible light’s energy falls between 2 and 3 electron volts.

Current NASA missions, including the Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory, also observe gamma rays, including those with even higher energies.

But for energies between 500,000 to 1 million electron volts, existing detectors are less sensitive. This range is where many powerful explosions called gamma-ray bursts shine the brightest. It’s also where astronomers expect to see the strongest glow from the most massive and distant active galaxies powered by black holes. By stacking AstroPix detectors in future missions, scientists could bridge this gap and improve observations of these cosmic objects to better understand the processes that create and drive them.

“The Fly Foundational Robots spacecraft is also a technology demonstration, so the projects were a good fit for each other,” said Dan Violette, an AstroPix team member and post-doctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We need to thoroughly test AstroPix’s performance before we can use the sensors in future science missions. We’ve flown comparable technologies on a scientific balloon mission, and the current prototype eventually will be part of a sounding rocket payload. Many of those flight opportunities only reach near space, though. It’s not often that technology demonstrations like ours can find a ride into orbit.”

Each AstroPix chip contains four silicon pixel gamma-ray detectors, and each detector incorporates 1,225 pixels. The chips function similarly to the sensors in cell phone cameras.

The AstroPix Satellite Technology dEmonstration Payload, also known as A-STEP, will be hosted within the Fly Foundational Robots mission’s Orbital Replacement Unit, a movable module built by Rocket Lab Robotics. Rocket Lab Robotics also will provide a robotic arm that will pick up and reposition the unit during flight and perform in-orbit operations as part of a robotic servicing demonstration. The A-STEP payload will collect its data following the repositioning. Astro Digital will provide the spacecraft.

The Orbital Replacement Unit was designed to support power and data interfaces for a payload, but the original plan called for the robotic arm to reposition the module without one. As mission development progressed, however, the Fly Foundational Robots team identified an opportunity to further maximize the mission’s value by integrating an additional technology demonstration that could fit within the 11.8-inch (30-centimeter) cube.

“The unit already had the volume, power, and data needed to support the AstroPix team’s design,” said Bo Naasz, senior technical lead, In-space Servicing, Assembly, and Manufacturing in the Space Technology Mission Directorate at NASA Headquarters in Washington. “One of our major goals with Fly Foundational Robots is to demonstrate robotic changeout of payloads in orbit, enabling upgrades or improvements to satellites and space instruments at a fraction of the cost of a full mission. Allowing AstroPix to complete its own technology demonstration in orbit is a bonus.”

The AstroPix team is working to deliver their hardware this September, and it will be integrated into the Fly Foundational Robots payload before final integration onto the spacecraft. The Orbital Replacement Unit will hold the chips and all the associated electronics needed to provide power, and collect and transmit data during flight.

NASA’s Fly Foundational Robots mission is funded through the Space Technology Mission Directorate’s ISAM portfolio, managed at NASA Goddard. Rocket Lab Robotics will supply the mission’s robotic arm system through a NASA Small Business Innovation Research Phase III award. Astro Digital will host the orbital flight test of the arm through NASA’s Flight Opportunities program, managed at NASA’s Armstrong Flight Research Center in Edwards, California. The development of AstroPix was supported by NASA’s Astrophysics Division in the Science Mission Directorate at NASA Headquarters, through the agency’s Astrophysics Research and Analysis Program, and funded through the Nancy Grace Roman Technology Fellowship.

To learn more, visit:

https://go.nasa.gov/3R28tWE

By Jeanette Kazmierczak
Goddard Space Flight Center, Greenbelt, Md.

New experiments suggest humans have a hidden counterclockwise bias.

NASA’s Parker Solar Probe completed its 28th close approach to the Sun on June 8, again matching its record distance of 3.8 million miles from the solar surface. The flyby allowed the spacecraft to continue its measurements of the solar wind and solar activity at their source, while adding to our understanding of how the Sun’s atmosphere changes throughout the solar cycle.

The spacecraft checked in with flight controllers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland — where Parker Solar Probe was designed and built — on Thursday, transmitting a beacon tone that indicated its systems were operating normally. Zooming around the Sun on a trajectory that limited communications with Earth, Parker had been out of contact and operating autonomously for nine days around its closest approach, as planned.
 
During this solar encounter, which started June 3 and ends Saturday, June 13, Parker’s four scientific instrument packages gathered data from inside the Sun’s atmosphere, or corona. Parker will begin returning detailed spacecraft telemetry on June 14, with science data transmission set to run from Wednesday, June 17 to Tuesday, June 30.
 
Parker’s observations of the solar wind and solar events, such as coronal mass ejections and the aftermaths of flares, are critical to advancing humanity’s understanding of the Sun and the phenomena that drive high-energy space weather events that pose risks to astronauts, satellites, air travel, and even power grids on Earth. Understanding the fundamental physics of space weather enables more reliable prediction of astronaut safety during future deep-space missions to the Moon and Mars.
 
Parker also equaled its record-setting speed of 430,000 mph — a mark that, like Parker’s distance to the Sun, was set during a close approach on Dec. 24, 2024, and matched during five flybys since, most recently on March 11. Parker will continue matching these speed and distance records during future flybys.
 
Through all six close approaches, mission leads say, the spacecraft has remained in excellent condition. While Parker doesn’t have a temperature sensor on the front of its heat shield — known as the Thermal Protection System, or TPS — the team can estimate through models that the heat shield reaches temperatures of about 1,700 degrees Fahrenheit at closest approach.

“The heat shield material is incredibly light and fragile, but the thermal design, as well as the software that keeps the spacecraft pointing the TPS toward the Sun, have been outstanding,” said John Wirzburger, Parker Solar Probe mission systems engineer at APL. “It’s a real tribute to the team that designed, built, and operates Parker Solar Probe.”
 
Meanwhile, the team can measure the temperature of the barrier blanketing below the heat shield, and the actual spacecraft temperature has remained consistent on each pass.
 
“That temperature consistency is a major indicator of spacecraft health,” said Wirzburger. “It tells us the heat shield isn’t degrading. If it were cracking or weakening, we’d see temperatures drift upward as more heat leaked through.”
 
Parker launched in August 2018. At the time, the Sun was near the minimum of its 11-year activity cycle. In 2024, representatives from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the international Solar Cycle Prediction Panel announced that the Sun had reached its solar maximum period. Parker’s 28 encounters with the Sun reflect this change over time, sampling the Sun’s atmosphere from quiet to very active periods. Parker Solar Probe will remain in this orbit around the Sun and continue making observations into the declining phase of solar activity.
 
The next steps for the mission in late 2026 and beyond are under NASA review.
 
Parker Solar Probe was developed as a part of NASA’s Living With a Star (LWS) program to explore aspects of the Sun-Earth system that directly affect life and society. The LWS program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. Johns Hopkins APL manages Parker Solar Probe for NASA and designed, built, and now operates the mission.
 
Mike Buckley, Johns Hopkins Applied Physics Laboratory

The post Parker Solar Probe Makes 28th Close Pass of Sun appeared first on NASA Science.

Physicists at the University of Oxford have created a new type of quantum state that could help advance quantum computing and deepen our understanding of the strange rules of the quantum world. The research builds on one of the most famous ideas in physics: Schrödinger’s cat. Proposed by physicist Erwin Schrödinger in 1935, the thought […]

The post Scientists create a new kind of Schrödinger’s cat state appeared first on Knowridge Science Report.

First dreamed up decades ago, the world's first nuclear clocks are set to improve quickly, becoming more precise and aiding the hunt for dark matter.

Physicists believe that 80% of the matter in the universe is made of ‘dark matter’ that we can’t see. But despite decades of work, they haven’t been able to confirm that this matter really exists. In the past years, physicists have been rethinking the dark matter idea… but not in the way you might expect. Let’s take a look.

Researchers from the private nuclear fusion energy company Commonwealth Fusion Systems have published a series of papers that they claim confirm that their flagship ARC reactor will produce more usable energy than it consumes if built as designed.

Although the company projects it will deliver the first commercial fusion plants by the early 2030s, other researchers say there are remaining challenges to overcome, and won’t declare the ARC reactor successful until an operational version is constructed to validate the research team’s theoretical predictions.

ARC Fusion Reactor ‘Will Work’ When Built

Scientists have long dreamed of capturing the nuclear fusion reaction that fuels our Sun and using it to generate clean, renewable power. Private fusion firms like CFS have received nearly $10 billion in funding over the last decade alone.

The first laboratory “net-energy” controlled fusion reaction, which fusion scientists call “ignition,” didn’t occur until 2022, when physicists at the US National Ignition Facility in Livermore, California, successfully produced more energy than was used to generate the reaction. Although brief, that moment has fueled speculation that practical fusion energy generation may be right around the corner.

Now, the Commonwealth team, which includes 58 researchers from the company and partner institutes, has published scientific papers outlining the physics of their ARC reactor, including new models that they say account for the “expected behavior” of the superhot plasma at the heart of the design.

Brandon Sorbom, the company’s chief science officer, said that the published works  “confirm that when we build the ARC fusion power plant, it will work”.

Company Claims ARC Will Produce 400 Megawatts of Net Electricity

After nearly a decade of research, CFS, founded in 2018, is currently preparing its prototype for a 2027 demonstration it calls ‘SPARC.’ The company said they expect that trial run, which will demonstrate their technology’s ability to generate more energy than it needs to heat the plasma, will help them fine-tune ARC’s final design.

According to the Commonwealth-led team, ARC will generate more energy than is required to operate the entire facility, including plasma heating, resulting in a true net-positive power-generation facility. This includes producing approximately 400 megawatts of net electricity, which the team noted is enough to power 280,000 average US homes. For comparison, recent census data indicates that Boston, Massachusetts, near the company’s headquarters in Cambridge, has around 271,000 U.S. homes.

Like SPARC, the ARC reactor uses high-temperature superconducting magnets to compress the plasma, which remains suspended by the magnetic fields, preventing it from damaging the chamber walls and terminating any potential fusion reaction. Under this extreme pressure, the nuclei of heavy hydrogen trapped inside the chamber fuse to form helium, the same reaction that takes place inside the Sun.

This fusion reaction results in the release of energy, primarily high-speed neutrons. At its hottest, the donut-shaped ring of plasma reaches seven times the temperature of the Sun.

Critics Applaud Publication While Highlighting Unproven Concepts and Systems

Tony Roulstone, a nuclear engineer at the University of Cambridge, UK, conceded that the CFS team and its collaborating authors are “some of the best in the fusion business” and noted the company’s ARC reactor concept is the result of “good work over many years.” However, Roulstone also warned of the pressure on researchers in privately funded companies to “claim things before the evidence is fully in place.”

David Hammer, a nuclear engineer at Cornell University in Ithaca, New York, said it is a good sign that the team is publishing at a high volume, but also warned that published papers will not guarantee that the built device will work as intended.

Their modeling “has to be proven correct by a fusion reactor that works as designed”, he adds. If the firm can get SPARC operating successfully next year, “it will be an important step forward”, he says.

Hamner also noted that several of the design’s subsystems require further development before it can be declared complete. This includes addressing how plasma will behave in the real world when it becomes unstable versus its modeled behavior, proving out the process for extracting usable energy from the generated heat, and demonstrating that the reactor is robust enough to operate for long periods.

The scientists also noted the challenges in sourcing tritium, the isotopic fuel the reactor requires to operate. Although CFS has outlined its tritium generation process, Hamner noted that the series of published papers neither details the process nor demonstrates its viability.

“There are candidate blanket materials and blanket designs, but there are many engineering person-years needed” to bring a functional ARC-style plant to fruition, he explained.

“We certainly have to build more on top of that foundation laid out in these papers,” a company spokesperson said, adding that they will “be able to produce tritium for operations and for future power plants.”

The following articles were published by the CFS-led team: “Overview of the physics basis for the ARC fusion power plant“; “ARC disruption physics and strategy“; “Performance and Transport in the ARC Tokamak“; “Power and particle exhaust for the ARC fusion power plant“; “ARC Physics Basis-Magnetohydrodynamics.”

Editor’s Note: This article was updated to correct a previous version that described neutrinos, rather than fast-neutrons, in the context of the reporting, and to clarify that the first achievement of a “net-energy” controlled fusion reaction (ignition) occurred in 2022. 

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.

A new study has taken a fresh look at a late 2025 Yonsei University study claiming the universe’s expansion is stalling out and instead has found that the universe is still expanding as previously believed.

Led by researchers from the University of Southampton, the team behind the new analysis acknowledged the scientific value of the 2025 team’s work, noting that their calculations were not wrong but lacked the additional data needed to confirm the universe’s expansion rather than refute it.

The lead author of the 2025 study, Dr. Chul Chung, told The Debrief that he and his colleagues “have already submitted our response to Wiseman, Riess et al. 2026 on May 14,” adding that the paper, “Still accelerating: age bias correction in supernova cosmology is robust to host-progenitor age mapping,” has also been posted on arXiv.

“The abstract summarizes the two main issues we identify in Wiseman et al., so I think it provides a concise overview of our position,” Chung told The Debrief.

Challenging Universal Expansion

According to a statement announcing the findings, scientists first confirmed the universe’s expansion was accelerating in 2011, a discovery that won astrophysicists Professor Adam Riess and Professor Brian Schmidt the Nobel Prize in Physics. Since that discovery, cosmological models have incorporated this accelerating expansion, with experiments on dark matter and dark energy attempting to explain it.

Then last year, a separate team of astronomers announced that a new analysis of stellar phenomena indicated that the universe was no longer expanding. Adding to the controversy was the team’s claim that dark energy may not exist, citing the lack of concrete evidence for a universe undergoing accelerating expansion.

According to the Southampton-led team behind the new study, the 2025 study suggested that previous methods used to measure the universe’s expansion, such as measuring supernovae, “were fundamentally flawed.”

“This points to a time-varying dark energy and a universe that is no longer accelerating, representing a potential paradigm shift in cosmology if confirmed,” explained Professor Chul Chung, co-lead author on the study, in a 2025 email to The Debrief.

The claims sent shockwaves through the scientific community, a result that the researchers note could have dismantled the Nobel Prize-winning team’s historic findings, and “nearly three decades of astronomical progress.”

When discussing the 2025 team’s work, the lead author of the new study, Dr Phil Wiseman, said the team’s findings and the resulting debate were not necessarily incorrect. Instead, the Southampton researcher said it was primarily a result of a scientific understanding.

“The previous and well-accepted measurements were, in fact, fine and our current understanding of the fate of the universe remains robust.”

Recalculating Galaxy Masses and White Dwarf Star Ages Reestablishes Expansion

In their reanalysis, the Southampton-led team recalibrated the original data to account for variables not in the original study. According to Wiseman, these included “different host environments and populations.”

For example, the research team looked at Type 1a supernovae, which are violet, extremely bright explosions of white dwarf stars. The authors of the 2025 study claimed that this class of supernova had “different maximum brightness,” which had tricked astronomers into thinking the cosmos was accelerating, when their analysis said it was actually slowing down.

When they took a fresh look at the data, the Southampton team found that they had incorrectly estimated the age of these stars. The new study also says the 2025 team didn’t account for the mass of the galaxies hosting these cosmological phenomena, which they described as “a standard correction used in modern cosmology to prove accuracy.”

When his team factored those data points in, Wiseman said the evidence for a stalling expansion was not supported. Instead, the researcher observed that “the evidence for cosmic acceleration remains remarkably consistent.”

In their reply on ArXiv, the Yonsei University team said the new research failed to factor in two variables of their own, adding that “when these two effects are consistently combined in computing the redshift-dependent magnitude correction, the final correction, and hence the resulting cosmological impact, remain largely unchanged,” from the original 2025 calculations.

“Extraordinary Claims Require Especially Careful Testing”

When discussing the new study’s findings, Southampton Professor Mark Sullivan highlighted the benefits of scientific review, noting that “this is how progress is made.”

“Although this idea did not turn out correct, it has opened up new ways of thinking about how supernovae explode and how we can measure dark energy more accurately,” the researcher added.

Paper co-author, Dr Brodie Popovic agreed, noting that the 2025 study provided astronomers a good opportunity to “go back over all of our assumptions,” adding that “it turns out, yes, we do understand this stuff, and we’re accounting for it in our cosmology measurement.”

In a salute to the Sagan Standard established by astronomer Carl Sagan, which says “extraordinary claims require extraordinary evidence,” Reiss seemed to celebrate the new findings that reestablish his original work by quipping that “extraordinary claims require especially careful testing.”

With the accelerating expansion of the universe seemingly reestablished, at least for now, Dr Wiseman said: “we can get back to trying to understand what dark energy actually is, rather than wondering if it exists at all.”

“Thankfully we have averted this crisis, but the mystery about why the universe is still accelerating in size remains,” he added. 

The study “Still Accelerating: Type Ia supernova cosmology is robust to host galaxy age evolution” was published in Monthly Notices of the Royal Astronomical Society.

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.

My book, "The Physics of Creation: The Creator’s Ultimate Design for Earth," is now available for download at CreationToday.org for under $5. The book offers a unique perspective on the universe, linking physical laws to an intelligent Creator, and explores how scientific principles align with the biblical creation narrative.