Magnetic diffusion in Solar atmosphere produces measurable electric fields

TL;DR

This study provides the first direct observational evidence of electric fields caused by magnetic diffusion in the solar atmosphere, using spectro-polarimetric measurements during a solar energetic event.

Contribution

It demonstrates the detection of electric fields associated with magnetic diffusion in the solar chromosphere through novel spectro-polarimetric observations and modeling.

Findings

Electric fields were detected at the site of a solar brightening event.

Polarization signals can only be explained by the presence of electric fields.

Results confirm magnetic diffusion as a mechanism for magnetic energy release in the solar atmosphere.

Abstract

The efficient release of magnetic energy in astrophysical plasmas, such as during solar flares, can in principle be achieved through magnetic diffusion, at a rate determined by the associated electric field. However, attempts at measuring electric fields in the solar atmosphere are scarce, and none exist for sites where the magnetic energy is presumably released. Here, we present observations of an energetic event using the National Science Foundation's Daniel K. Inouye Solar Telescope, where we detect the polarization signature of electric fields associated with magnetic diffusion. We measure the linear and circular polarization across the hydrogen H-epsilon Balmer line at 397 nm at the site of a brightening event in the solar chromosphere. Our spectro-polarimetric modeling demonstrates that the observed polarization signals can only be explained by the presence of electric fields, providing conclusive evidence of magnetic diffusion, and opening a new window for the quantitative study of this mechanism in space plasmas.