The Persistence of Apparent Non-Magnetostatic Equilibrium in NOAA 11035

TL;DR

This paper investigates a persistent, unusual magnetic feature in NOAA 11035, suggesting it may be a force-free magnetic field caused by low-atmosphere magnetic reconnection, based on comprehensive multi-instrument observations.

Contribution

It presents detailed multi-wavelength observations of a unique, long-lasting magnetic structure in NOAA 11035, proposing a novel interpretation involving force-free fields and magnetic reconnection.

Findings

Persistent opposite polarity pore with >3500 G magnetic field

Evidence of magnetic reconnection in the low solar atmosphere

Possible force-free magnetic field configuration

Abstract

NOAA 11035 was a highly sheared active region that appeared in December 2009 early in the new activity cycle. The leading polarity sunspot developed a highly unusual feature in its penumbra, an opposite polarity pore with a strong magnetic field in excess of 3500 G along one edge, which persisted for several days during the evolution of the region. This region was well observed by both space- and ground-based observatories, including Hinode, FIRS, TRACE, and SOHO. These observations, which span wavelength and atmospheric regimes, provide a complete picture of this unusual feature which may constitute a force-free magnetic field in the photosphere which is produced by the reconnection of magnetic loops low in the solar atmosphere.