Constraining the onset height of coronal mass ejection driven shocks using near-Sun observations in visible and radio wavelengths

TL;DR

This paper investigates the height at which shocks associated with coronal mass ejections form near the Sun by combining visible and radio observations, addressing a key debate in solar physics.

Contribution

It demonstrates the potential of joint observations from VELC on ADITYA-L1 and radio facilities to constrain the onset height of CME-driven shocks.

Findings

Joint observations can help determine shock formation heights.

Radio and visible data together improve understanding of CME shock onset.

Methodology offers new insights into early CME shock development.

Abstract

One of the debated issues about the onset of the type II radio bursts near the Sun is the heliocentric distance ($r$) at which the associated magnetohydrodynamic (MHD) shocks are formed, and the association of the latter with the coronal mass ejections (CMEs). The debate is primarily due to the absence of routine CME observations in whitelight at $r\,{<}\,1.5R_{\odot}$. We present here an example for how joint observations with the Visible Emission Line Coronagraph (VELC) onboard the recently launched ADITYA-L1 (the first dedicated Indian space solar mission, \citealp{Parate2025}), and Gauribidanur radio facilities could be useful to address the issue.