The Aditya-L1 mission is India’s first scientific mission dedicated to studying the Sun.
| Photo Credit: X/Ani/ISRO
Scientists from the Indian Institute of Astrophysics (IIA) have reported observations of a flareless coronal mass ejection (CME) from the solar atmosphere with the Visible Emission Line Coronagraph (VELC) instrument onboard Aditya-L1 mission.
The Aditya-L1 mission is India’s first scientific mission dedicated to studying the Sun and the VELC payload was developed by the Bengaluru-based IIA.
Scientists associated with the IIA said that using the VELC payload, it was possible to observe the corona not only closer to where its base is located in the solar atmosphere, but also obtain data at shorter time intervals compared to other existing coronagraphs in orbit.
The VELC team observed the onset of a CME that erupted from the Sun on July 5, 2024, with no association to any flare.
Magnetic instability
They said that the data obtained provides valuable clues to understand and differentiate the magnetic instabilities on the Sun that causes the flares and the CMEs.
The results of the study will be appearing soon in the Astrophysical Journal, an international peer-reviewed scientific journal.
“Observation of CMEs as and when they originate on the Sun and understanding their association with flares is one of the major science goals for VELC, and we are happy that the instrument is doing that,” said R. Ramesh, senior professor at the IIA and the principal investigator for the VELC.
Prof. Ramesh added that with the Sun approaching the maximum phase of the current solar cycle 25, the CMEs are expected to occur frequently.
“Hence, uninterrupted monitoring of the Sun with VELC for CMEs is expected to provide valuable data to the Indian and international scientific community. The unique design of VELC helps to observe the CMEs close to the limb of the solar surface, and their onset time. These advantages facilitate better investigation of the association between CMEs and flares near the solar limb,” Prof. Ramesh added.
What are flares and CMEs?
Flares and CMEs are explosive events in the Sun. They are due to magnetic reconnection during which magnetic field lines rearrange.
During a flare, energy is released primarily as electromagnetic radiation from the heated plasma. Compared to flares, the CMEs are massive eruptions of plasma and magnetic field weighing about trillion kilograms that race outwards from the Sun through the interplanetary space at speeds up to 3,000 kilometres per second. The association between flares and CMEs is ambiguous till date.
Published – March 14, 2025 09:46 pm IST
