Astronomers from the Indian Institute of Astrophysics (IIA) have made a major breakthrough in understanding how dangerous solar storms begin. Using the ground-based Gauribidanur radio telescope and the Visible Emission Line Coronagraph (VELC) payload on India's Aditya-L1 satellite, the team captured the closest-ever observations of shock waves triggered by a coronal mass ejection (CME) near the Sun. This critical discovery occurred on May 27, 2024, revealing shock waves forming approximately 130,000 kilometers above the Sun's surface and traveling at nearly 1,700 kilometers per second.[thehindu+2]
Unveiling Solar Eruption Origins
The recent observations provide unprecedented detail into the "birth stage" of solar shock waves, a phenomenon scientists have debated for nearly a century.Coronal Mass Ejections are massive bursts of solar plasma and magnetic fields ejected from the Sun's outer atmosphere.When these fast-moving CMEs erupt, they generate shock waves, similar to a sonic boom from a supersonic aircraft.These shocks can compress Earth's magnetosphere, potentially leading to geomagnetic storms that disrupt satellites, GPS systems, radio communications, and even power grids.[indiatoday+5]
Professor R. Ramesh, a Senior Professor at IIA and Principal Investigator of VELC, highlighted the significance of the findings. "This is the closest distance from the Sun at which such a shock and its associated radio burst have been unambiguously detected," Professor Ramesh stated.The ability to pinpoint the origin of these shocks is crucial for predicting their evolution and impact on Earth.[indiatoday+2]
Aditya-L1's Eye on the Sun
Aditya-L1, India's first dedicated space-based solar mission, was launched on September 2, 2023, and successfully placed into a halo orbit around the Sun-Earth Lagrange Point 1 (L1) on January 6, 2024.This strategic location, about 1.5 million kilometers from Earth, offers an uninterrupted view of the Sun, free from eclipses or occultations.This continuous observation capability is vital for studying the dynamic processes of the solar atmosphere.[isro+8]
The Visible Emission Line Coronagraph (VELC) is a key payload on Aditya-L1, developed by the IIA.It is designed to image the solar corona, the Sun's outermost layer, in detail.VELC's observations are instrumental in identifying the specific CMEs that give rise to these powerful shock waves.The payload also provides spectroscopic observations, allowing scientists to measure CME parameters very close to the Sun's surface.[thefederal+6]
Ground-Based Radio Power
The Gauribidanur Radio Observatory, located approximately 100 kilometers north of Bengaluru, played a crucial role in these observations.Operated by the IIA, it is currently India's only dedicated low-frequency solar radio observatory.Radio telescopes like Gauribidanur detect intense bursts of low-frequency emissions, typically below 150 MHz, which are characteristic signatures of shocks near the Sun.This ground-based facility complements the space-based observations from Aditya-L1, creating a powerful combined observational platform.[thehindu+7]
The collaboration between the Gauribidanur radio telescope and Aditya-L1's VELC payload allowed the IIA team to precisely estimate the onset distance of the CME-driven shock.This synergy of instruments provides a comprehensive view of solar events, from their genesis near the Sun to their propagation through interplanetary space.[thehindu+1]
Capturing Solar Flares in New Detail
Beyond the CME shock observations, Aditya-L1 has delivered other groundbreaking insights. On February 22, 2024, the Solar Ultraviolet Imaging Telescope (SUIT) payload onboard Aditya-L1 captured the first-ever image of a solar flare "kernel" in the lower solar atmosphere.This X6.3-class solar flare, one of the most intense categories of solar eruptions, was observed in the Near Ultraviolet (NUV) wavelength range (200-400 nm), a band never before seen in such detail.[isro+6]
These SUIT observations confirmed that the energy released from the flare spreads through different layers of the Sun's atmosphere.This provides new insights into the complex physics driving these massive solar explosions.The SUIT instrument, developed by the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in collaboration with ISRO, opens up an unprecedented window for observing the Sun at NUV wavelengths without atmospheric interference.[isro+6]
Broader Impact on Space Weather Science
The continuous observations from Aditya-L1, combined with ground-based facilities, are significantly advancing the understanding of space weather. Space weather refers to conditions in space caused by solar activity, which can affect satellites, communication, navigation services, and power grids on Earth.By studying phenomena like CMEs and solar flares, scientists can better predict their impact and help protect critical infrastructure.[isro+3]
Aditya-L1 carries seven payloads in total, including the Aditya Solarwind Particle Experiment (ASPEX), which measures solar wind ions, and a Magnetometer (MAG), which monitors interplanetary magnetic fields.These instruments work together to provide a holistic picture of the Sun's behavior and its influence on the space environment around Earth.The data collected will help address longstanding questions about solar wind properties, coronal heating, and the acceleration mechanisms of energetic particles.[isro+9]
These recent findings mark a significant step in India's contribution to global solar physics and space weather research. They underscore the importance of combining advanced space-based observatories with ground-based facilities to gain a deeper understanding of our star and its powerful effects.[pib]
