ESTIMATING THE CRUCIAL PARAMETERS OF SUN'S CME

CIENTISTS at the Indian Institute of Astrophysics (IIA), Bengaluru, and National Aeronautics & Space Administration (NASA), USA, have collaborated to estimate the crucial parameters of a coronal mass ejection (CME), very close to its liftoff from the Sun, with the Visible Emission Line Coronagraph (VELC), the primary instrument on Aditya-L1 mission - India's maiden solar observatory designed to study the Sun.

- BALA CHAUHAN @Bengaluru

Prof R Ramesh, senior professor, IIA and principal investigator, VELC project, says these are the very first spectroscopic observations of a CME in the visible wavelength range.

"The inner solar corona, starting from the visible surface of the Sun out to approximately 200,000 km, is the region where the imprint of the physical processes responsible for Sun induced disturbances in the interplanetary medium, heliosphere, and geomagnetic storms in the near-Earth space (space weather) are pronounced. Transient disturbances like the CMEs are however usually observed in white light only when they have propagated well away from the Sun's surface," he explains. "The near-Sun characteristics of CMEs remain less understood due to this, as well as lack of continuous observations. In the case of ground-based observations, total solar eclipses provide the sole opportunity for exploring the inner corona, but for a few minutes only. Long duration, uninterrupted monitoring of the Sun is a must to study these transients," says Ramesh.