Solar Coronal Magnetic Fields and Sensitivity Requirements for Spectropolarimetry Channel of VELC Onboard Aditya-L1

TL;DR

This paper discusses the importance of measuring solar coronal magnetic fields, reviews techniques for their estimation, and analyzes the sensitivity requirements for the VELC spectropolarimetric instrument onboard Aditya-L1.

Contribution

It provides an overview of methods to estimate coronal magnetic fields and details the sensitivity specifications needed for VELC's spectropolarimetric measurements.

Findings

Summarizes techniques for coronal magnetic field estimation.

Estimates required measurement sensitivities for VELC.

Highlights the importance of accurate spectropolarimetric data.

Abstract

Understanding solar coronal magnetic fields is crucial to address the long-standing mysteries of the solar corona and solar wind. Although routine photospheric magnetic fields (MFs) are available for decades, coronal MFs are rarely reported. Visible Emission Line Coronagraph (VELC) on board Aditya-L1 mission (planned to launch in the near future) can directly measure the MFs in the inner solar corona. This can be achieved with the help of spectropolarimetric observations of the forbidden coronal emission line centered at 1074.7 nm over a field of view 1.05 R$_{\odot}$ - 1.5 R$_{\odot}$. In this article, we summarize various direct and indirect techniques used to estimate the MFs at different wavelength regimes. Further, we summarize the expected accuracies that are required to estimate MFs using VELC's spectropolarimetry channel.