Aditya-L1: IIA-NASA collaborate to record spectroscopic observations of a CME in visible wavelength range for very first time

Using the VELC payload aboard India’s first dedicated space-based solar mission, Aditya-L1, scientists at the Indian Institute of Astrophysics (IIA) collaborated with NASA to predict key parameters of a coronal mass ejection (CME) very close to liftoff from the Sun.

Scientists associated with the project said these are the first spectroscopic observations of a CME in the visible wavelength range.

They said the unique spectroscopic observations made with VELC allowed them to examine CMEs very close to the Sun’s visible surface for the first time.

“It also provides a continuous view of the Sun 24 hours a day, due to its location at Sun-Earth Lagrangian L1, where the Sun never sets,” they said.

Benefiting from these, Dr. V. Muthupriyal (VELC Project Scientist) and colleagues at the VELC payload operations center at IIA estimated the electron density, energy, mass, temperature, and velocity of a CME very close to the Sun.

IIA Senior Professor and principal investigator of the VELC project Prof. R. Ramesh said: Hindu The observations are by far the closest to the Sun, and spectroscopic observations of a CME in the visible wavelength range have been obtained with a space coronagraph.

His team calculated that there are approximately 370 million electrons per cubic centimeter in the CME observed with VELC.

The corresponding number for the non-CME corona near the Sun is much less; It ranges from 10 to 100 million electrons per cubic centimeter.

“In the current case, the CME energy is about 9.4 * 1021 Joules. For example, the yield of the atomic bombs used in Hiroshima and Nagasaki (nicknamed “Little Boy” and “Fat Man”) are about 6.3 * 1013 Joules and 8.8 * 1013 Joules, respectively. The mass in the CME is about 270 million tons. For comparison, the mass of the iceberg “The sinking of the Titanic is estimated to be 1.5 million tons. The initial speed of the CME is 264 km/sec. The temperature of the CME is 1.8 million degrees on the Kelvin scale,” he said.

He also added that although there have been CME observations at relatively greater distances from the Sun with instruments other than VELC, understanding the parameters of a CME regarding how much is lost from the Sun during a CME is crucial, and unique near-Sun spectroscopic observations with VELC provide us with exactly the data needed.

Prof. Ramesh added that with the Sun approaching phase 25 of maximum activity of the current sunspot cycle and the VELC now stabilizing in its operations, larger and more energetic outbursts from the Sun are expected to be observed with the VELC in the coming months.