HINODE Observations of Chromospheric Brightenings in the Ca II H Line during small-scale Flux Emergence Events

TL;DR

This study uses Hinode observations to analyze chromospheric Ca II H brightenings linked to small-scale magnetic flux emergence, revealing energy release mechanisms in the solar chromosphere.

Contribution

First observational evidence connecting Ca II H brightenings with small-scale flux emergence, supporting simulation predictions of magnetic interactions and energy release.

Findings

Ca II H brightenings are associated with flux emergence events.

Energy is released through magnetic interactions in the chromosphere.

Observations support recent 3D numerical simulation results.

Abstract

\ion{Ca}{2} H emission is a well-known indicator of magnetic activity in the Sun and other stars. It is also viewed as an important signature of chromospheric heating. However, the \ion{Ca}{2} H line has not been used as a diagnostic of magnetic flux emergence from the solar interior. Here we report on Hinode observations of chromospheric \ion{Ca}{2} H brightenings associated with a repeated, small-scale flux emergence event. We describe this process and investigate the evolution of the magnetic flux, G-band brightness, and \ion{Ca}{2} H intensity in the emerging region. Our results suggest that energy is released in the chromosphere as a consequence of interactions between the emerging flux and the pre-existing magnetic field, in agreement with recent 3D numerical simulations.