SPACE/COSMOS
Texas Tech researchers probe interstellar explosions, unlock knowledge
Researchers in the Department of Physics & Astronomy at Texas Tech University recently used audio to represent the spectacular explosion of a star in deep space while also delving into the data to better understand how the phenomenon unfolded.
The explosion of NovaV612 Scuti, also known as ASSASSN-17hx, was discovered in 2017 and observed by astronomers around the world. Those observations produced data allowing researchers to study how the eruption changed over time. At Texas Tech the work has been led by undergraduate student Pragati Acharya under the guidance of Assistant Professor Elias Aydi.
By transforming the nova’s changing light into audio, the team has added a new dimension to understanding how the explosion unfolded.
“This sonification allows people not only to see the changing brightness of the explosion, but also to hear its evolution,” Aydi said. “In other words, we can now offer audiences a way to experience what a stellar explosion might ‘sound’ like when astronomical data are translated into audio.”
The findings have been accepted for publication in the journal Monthly Notices of the Royal Astronomical Society (Oxford Press).
A nova occurs when a dense stellar remnant, known as a white dwarf, pulls material from a companion star. As that material builds up on the white dwarf’s surface, it can trigger a sudden thermonuclear explosion, causing the system to brighten dramatically.
Aydi explained that although scientists have long studied these explosions, recent discoveries have changed how researchers understand these event
These discoveries led astronomers to explore how novae could produce such energetic radiation. One explanation centers on shock waves. During a nova eruption, gas can be ejected at different speeds. Later faster-moving material may collide with gas ejected earlier, creating powerful shocks.
The shocks also heat the surrounding gas, causing it to radiate at visible wavelengths. Recent studies have shown that much of the visible light typically observed from novae, long thought to come primarily from nuclear reactions on the surface of the white dwarf, may instead originate, at least in part, from the shock-heated gas.
To investigate the eruption, the researchers used spectroscopy, a technique that separates light into different wavelengths, much like spreading light into the colors of a rainbow. This allows astronomers to measure how strongly the object emits at different wavelengths and to track the motion of gas during the explosion.
Astronomers around the world observed V612 Scuti using spectroscopy and shared their data with the broader scientific community. The Texas Tech team used those observations to examine when the brightness jumps occurred, what caused them and how the gas moved during the eruption.
Aydi said the team found evidence that new ejections occurred with each jump in the light curve. By studying shifts in the spectra, they were also able to calculate the velocity of the material. Over several months of observations, they found that the gas increased significantly in velocity with each major jump.
The team decided to take the analysis a step farther.
“We had high-resolution spectra, which measure intensity versus frequency, and we said, ‘We can actually convert this extensive set of data into an equivalent of sound.’” Aydi said. “So, we converted the intensity of light into sound pitch and the frequency of light into frequency of sound.”
Acharya carried out much of the data analysis, including creating the figures for the paper and producing the sonification. She said she gained valuable experience in coding, spectroscopy and astronomical data analysis.
“I realized how it works bit by bit, code by code, and what the sonification script actually does,” she said. “When I did it all by myself and changed the wavelengths into frequencies and produced a sound, it felt like the best thing I had ever done, and it’s something I will never forget.”
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Earth's ionosphere supplied vast majority of ring current ions during May 2024 super geomagnetic storm, study finds
Despite the dense solar wind, solar wind ion contributions to the ring current during the May 2024 superstorm were minimal — the first simultaneous observation of ring current ions and solar wind during a storm this large.
Nagoya University
image:
An image of the Arase satellite observing ring current ions during the super geomagnetic storm.
view moreCredit: ERG Science Team
In May 2024, auroras were observed at unusually low latitudes across the globe, lighting up skies that rarely see such displays. Inside Earth’s magnetosphere, the region of space surrounding our planet and dominated by its intrinsic magnetic field, something significant was finally being observed.
It started with a large sunspot firing a rapid series of powerful solar eruptions. Clouds of magnetized plasma merged as they traveled through space and impacted Earth's magnetosphere. No geomagnetic storm this powerful had ever been measured in the Earth’s ring current region, a belt of charged particles in space near our planet.
Two sources of ring current ions are known: solar wind and Earth's ionosphere, the electrically charged upper layer of the atmosphere. For decades, scientists have debated how much each source contributes to the ring current. During most storms, both contribute. However, during a storm driven by a dense solar wind, some scientists expected solar wind ions to continue to play a notable role. Yet the first direct measurements of ring current composition from a super geomagnetic storm revealed that solar wind ion contributions were minimal, and the level of Earth-origin ion dominance had never been observed before.
The findings, published in Science Advances, suggest that understanding how much Earth's ionosphere contributes to the ring current may be essential to accurately predict the severity of super geomagnetic storms. The dominance of ionospheric ions, which are far heavier than solar wind particles, may have intensified the magnetic disturbance and concentrated the ring current peak unusually close to Earth. The researchers also make a case for a proposed Japanese multi-satellite mission to understand exactly how ion supply processes work.
Earth’s ring current
On May 10 and 11, 2024, giant clouds of charged particles from the Sun struck Earth's magnetosphere. The resulting May 2024 super geomagnetic storm, also referred to as the “Gannon storm” or “Mother's Day storm,” reached a minimum SYM-H index of −518 nanotesla, the second-largest value recorded since 1981. The last comparable geomagnetic storm was the November 2004 superstorm.
“Some super or extreme geomagnetic storms are not just impressive light shows—they pose radiation risks to spacecraft, disturb GPS signals and communications, and cause power outages. Understanding how a geomagnetic storm develops is not only a scientific question, but also one with real-world consequences,” said Naritoshi Kitamura, lead author and designated assistant professor from the Institute for Space-Earth Environmental Research (ISEE) at Nagoya University.
The magnetic disturbance of a geomagnetic storm is caused by the ring current. This is a huge belt of energized ions, mostly oxygen and hydrogen, that drift slowly around Earth thousands of kilometers above the equator. The energized ions carry current, and that current generates a magnetic field that partially cancels Earth's own on the ground. This causes the disturbance that is observed by ground-based instruments.
Arase was ready: rare event, first of its kind observation
Japan's Arase satellite was launched in 2016 and has been operated by the Japan Aerospace Exploration Agency (JAXA). The ERG (Arase) science center is jointly operated by Institute of Space and Astronautical Science (ISAS)/JAXA and Institute for Space-Earth Environmental Research/Nagoya University.
Arase orbits the region where the ring current develops. The satellite carries specialized instruments to identify mass and energy of detected ions. It crossed through the ring current just after the storm began, and again near its peak.
“This is the first simultaneous observation of ring current ions and solar wind during a storm this large, and the data was clear—approximately 85% of ions were oxygen from Earth's own ionosphere,” Kitamura explained.
“Near the peak of the storm, Arase detected a 40% decrease in magnetic field intensity at roughly 16,000 kilometers above Earth, and much closer to Earth than similar large decreases previously documented.”
The same region also showed a simultaneous drop in high-energy electrons that normally orbit Earth in that zone. When a magnetic field weakens this severely, electrons drift out from their normal paths. Whether the magnetic field deformation caused the electron loss warrants further investigation.
The findings deepen our understanding of how super geomagnetic storms develop. Space weather forecasting models rely on solar wind conditions to predict storm severity, but this study suggests Earth's atmospheric state, and not just conditions at the Sun, may partly determine how severe a storm becomes.
The study also supports FACTORS, a two-satellite mission concept being prepared for JAXA’s upcoming proposal opportunity, which would directly address this gap. FACTORS aims to improve our understanding of how Earth's atmospheric ions escape into the magnetosphere and contribute to geomagnetic storm development. It may ultimately help scientists more accurately predict how severe these storms will get.
Schematic image of ring current ions (IMAGE)
Schematic image of ring current ions on the dusk side during the peak of the May 2024 super geomagnetic storm, viewed from the Sun's perspective.
Credit
ERG Science Team
Japan's Arase satellite lifts off in December 2016. The spacecraft orbited for more than seven years before the May 2024 super geomagnetic storm finally provided the opportunity to measure ring current composition directly.
Credit
Naritoshi Kitamura
Journal
Science Advances
Method of Research
Data/statistical analysis
Article Title
Extreme dominance of Earth-origin heavy ions in the intense ring current near the Earth during the May 2024 super geomagnetic storm
Article Publication Date
26-Jun-2026
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