New Results on the Onset of a Coronal Mass Ejection from 5303 {\AA} Emission Line Observations with VELC/ADITYA-L1

TL;DR

This paper presents spectroscopic observations of a coronal mass ejection (CME) using the 5303 Å emission line from VELC on ADITYA-L1, providing insights into the CME's onset time and associated plasma dynamics.

Contribution

First spectroscopic detection of CME onset with VELC on ADITYA-L1, constraining timing and plasma parameters during the event.

Findings

50% decrease in coronal intensity near CME source

15% increase in emission line width

10 km/s redshifted Doppler velocity

Abstract

We report on the onset of a coronal mass ejection (CME) using spectroscopic observations in 5303 {\AA} coronal emission line with the Visible Emission Line Coronagraph (VELC) onboard ADITYA-L1, the recently launched first Indian space solar mission. The CME was observed on 16 July 2024 in association with a X1.9 class soft X-ray flare from heliographic location S05W85. The VELC observations were near the west limb of Sun during the CME. The results obtained helped to constrain the onset time of the CME. In addition, they indicate ${\approx}$50% decrease in the coronal intensity near the source region of the CME due to mass depletion, ${\approx}$15% enhancement in the emission line width, and redshifted Doppler velocity of about ${\approx}10$ km/s. The non-thermal velocity associated with the line broadening is ${\approx}24.87$ km/s.