Assam: Tezpur University researchers uncover mechanism of energy transport on the Sun

Our Correspondent

Tezpur: The Sun is not just a glowing ball of light and heat—it is a dynamic, constantly active star that regulates Earth’s atmosphere and supports life. Beneath its bright surface, powerful waves and energetic particles move continuously, carrying energy outward through its surface. Understanding how this energy flows is crucial, as it influences solar eruptions, space weather, and even disturbances in Earth’s magnetic environment.

Researchers from Tezpur University, Assam, have made a significant breakthrough in solar physics by revealing how high-energy particles can reshape oscillations on the Sun’s surface and influence the energy transport into its lower atmosphere. The study titled “Analysis of Solar Surface Oscillations and Energy Transport with Bispectral Electronic Thermostatistics” was conducted by Mr Souvik Das, Senior Research Fellow (DST-INSPIRE), and Prof. Pralay Kumar Karmakar, project supervisor, from the Department of Physics. It has recently been published in The Astrophysical Journal (ApJ), one of the world’s most prestigious journals in astronomy and astrophysics, published by the American Astronomical Society (AAS). The reported findings shed new light on a long-standing mystery of how energy moves through the Sun—a complex physical process—closely linked to solar magnetic activities and space-weather events.

The Sun’s surface is constantly vibrating due to naturally excited sound-like waves known as five-minute solar oscillations. These vibrations make the Sun behave like a giant ringing bell or a musical resonator. Scientists have long believed that such oscillations help transport energy upward from the solar surface into the Sun’s atmosphere. However, the precise mechanisms by which this energy survives, evolves with height, and interacts with energetic particles have remained largely unexplored.

In the reported study, the researchers developed an advanced theoretical model that accounts for both low- and high-energy electrons present in the solar plasmas. Unlike the conventional approach, this model realistically captures the influences of fast-moving, high-energy particles—known as nonthermal electrons—on the solar surface oscillations.

The investigation demonstrates that stronger nonthermal effects weaken certain solar waves, particularly pressure-driven p-mode oscillations. As high-energy electron populations increase, the strength of such wave motions decreases, indicating that energetic particles can suppress wave activity and alter how acoustic wave energy is redistributed in the Sun’s lower atmosphere. This transported energy offers an additional power source to drive spicules, microspicules, and atmospheric waves and hence plays a crucial role in heating the solar chromosphere and corona—the Sun’s outer layers, which are much hotter than its visible surface.

“Our results show that some fast oscillations on the Sun’s surface can carry much more energy than that previously thought. At the same time, strong nonthermal effects can suppress certain oscillations, offering a clearer picture of how energy is balanced and transported in the Sun’s atmosphere,” said Souvik Das, lead author of the study.

In addition, the researchers also proposed a new hybrid decay model to explain how this p-mode–driven energy gradually diminishes as it travels upward from the solar surface. Rather than disappearing abruptly, the energy fades steadily with height due to a combination of atmospheric and magnetic effects within the Sun. This work offers fresh insights into the energetics of solar surface oscillations and helps scientists better estimate how much energy reaches different outer layers of the Sun.

Importantly, the model’s predictions were validated using high-quality observations from the Helioseismic and Magnetic Imager (HMI) onboard NASA’s Solar Dynamics Observatory (SDO), along with data from Japan’s Hinode Solar Optical Telescope, confirming the real-world relevance of the investigated findings.

“This work clearly demonstrates how suprathermal electron populations can strongly influence the solar surface oscillations and energy transport, successfully bridging theoretical modelling with observational evidence,” said Prof. Pralay Kumar Karmakar, Professor of Physics and supervisor of the study.

Realising physically how energy moves through the Sun is vital, not only for fundamental science but also for predicting solar storms that can disrupt satellites, power grids, and communication systems on Earth. (IANS)

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