The recent findings from the Aditya-L1 mission, India’s inaugural space-based solar observatory, have unveiled significant breakthroughs concerning Coronal Mass Ejections (CMEs) – massive outbursts of solar plasma and magnetic fields emitted from the outer atmosphere of the Sun. These findings, which have been published in The Astrophysical Journal Letters, provide crucial insights into the Sun’s corona and its effects on space weather.
LaunAditya-L1 was launched on September 2, 2023, and in January 2024, it was positioned in a halo orbit around the primary Sun-Earth Lagrange Point (L1), which is located 1.5 million kilometers away from Earth.ched on September 2, 2023, Aditya-L1 was placed in a halo orbit around the first Sun-Earth Lagrange Point (L1), 1.5 million kilometers from Earth, in January 2024.
By utilising the Visible Emission Line Coronagraph (VELC) on the spacecraft, scientists were able to observe a coronal mass ejection (CME) event on July 16, 2024, along with a strong solar flare. The VELC instrument enabled researchers to analyze the Sun’s corona in green light emitted at a wavelength of 5303 Å, produced by iron atoms at temperatures surpassing one million degrees Celsius.
What is a Coronal Mass Ejection (CME)?
A Coronal Mass Ejection (CME) is a significant expulsion of solar wind and magnetic fields from the Sun’s corona. During a CME, substantial quantities of charged particles, such as electrons and protons, as well as plasma, are propelled into space at incredibly high velocities, often reaching speeds of millions of kilometers per hour. When a CME reaches Earth, it can interact with our magnetic field, causing disruptions that can impact satellite communications, GPS systems, and power grids.
CMEs result from magnetic disturbances in the Sun’s corona. The Sun’s magnetic field is in a constant state of flux, undergoing continual changes and shifts. These alterations can lead to the twisting and stretching of magnetic field lines. When these fields suddenly realign or reconnect, they release a large amount of energy, propelling solar material outward into space and triggering a CME.
The sudden burst of energy is commonly linked with solar flares, although coronal mass ejections (CMEs) can also occur independently. The precise relationship between CMEs and solar flares remains a scientific enigma. Comprehending the origins and patterns of CMEs is essential for forecasting their impact on Earth and safeguarding our technology from space weather risks.
Temperature and Turbulence
During the event, the coronal mass ejection (CME) resulted in a 30% increase in temperature in the surrounding region, coupled with increased turbulence. The rapid movement of plasma, clocked at 24.87 km/s, indicated heightened magnetic activity of the Sun. This turbulence, driven by the dynamic magnetic fields of the Sun, provides valuable insights into the conditions preceding such eruptions. Doppler velocity measurements showed that the ejected plasma exhibited a redshift, indicating its movement away from the observer at a speed of 10 km/s.
The deflection of the coronal mass ejection (CME) by the Sun’s magnetic field indicates the importance of predicting its path through the solar system, which could have potential impacts on Earth and other planets. This highlights the critical role of Aditya-L1 in studying the Sun’s corona, a region hotter than its surface and crucial for space weather forecasting.
These observations contribute to our knowledge of solar activity and its influence on the interplanetary environment, representing a significant milestone in India’s solar exploration endeavors.