Flux rope proxies and fan-spine structures in active region NOAA 11897

TL;DR

This study uses high-resolution solar observations to identify flux rope proxies and fan-spine structures in active region NOAA 11897, revealing complex magnetic configurations with multiple flux ropes that do not erupt.

Contribution

First detection of 30 flux rope proxies and a secondary fan-spine structure in NOAA AR 11897, highlighting the magnetic complexity of active regions.

Findings

30 flux rope proxies detected in four locations

Flux ropes observed in both low and high temperature wavelengths

No flux rope eruptions observed, only gradual fading

Abstract

Employing the high-resolution observations from the Solar Dynamics Observatory (SDO) and the Interface Region Imaging Spectrograph (IRIS), we statistically investigate flux rope proxies in NOAA AR 11897 from 14-Nov-2013 to 19-Nov-2013 and display two fan-spine structures in this AR. For the first time, we detect flux rope proxies of NOAA 11897 for total 30 times in 4 different locations. These flux rope proxies were either tracked in both lower and higher temperature wavelengths or only detected in hot channels. Specially, none of these flux rope proxies was observed to erupt, but just faded away gradually. In addition to these flux rope proxies, we firstly detect a secondary fan-spine structure. It was covered by dome-shaped magnetic fields which belong to a larger fan-spine topology. These new observations imply that considerable amounts of flux ropes can exist in an AR and the complexity of AR magnetic configuration is far beyond our imagination.