Structure and dynamics of erupting solar prominences using the Rolling Hough Transform: Toward a feature-oriented classification

TL;DR

This paper introduces the spatial Rolling Hough Transform (RHT) as a new method to analyze the structure and dynamics of erupting solar prominences, enabling feature-oriented classification based on detailed structural orientation.

Contribution

The paper presents a proof-of-concept application of the RHT algorithm to prominence observations, providing a novel way to classify prominence structures and understand their dynamic phases.

Findings

RHT effectively identifies structural orientations in prominence data.

Prominences show different structural orientations during various dynamical phases.

The method enables classification of prominences as radially or tangentially oriented.

Abstract

The classification of solar prominences has proven to be challenging due to their diverse morphologies and dynamical behaviour. Complexity is heightened when considering eruptive prominences, where the dynamics demand methods capable of capturing detailed structural information. While there exists a range of line-of-sight (LOS) and plane-of-sky (POS) techniques which have advanced our understanding of prominence motions, they are subject to limitations, emphasising the need for effective methods of extracting structural information from prominence dynamics. We present a proof-ofconcept for the spatial Rolling Hough Transform (RHT) algorithm, which identifies finescale structural orientation in the POS, applied to prominence structure and dynamics. We demonstrate the RHT approach using two contrasting prominence dynamics events using SDO/AIA 304 \r{A} observations: (1) a quiet-Sun eruption, (2) activation (swirl) of a polar-crown prominence. By analysing the light curves and movies from each event, we divide the events into distinct dynamical phases: from slow rise to drainage. The spatial RHT method enables us to extract structural information and localised dynamics for both events and the different evolution phases. We develop a classification to label the prominences as either radially or tangentially oriented structures. The quiet-Sun eruption has a predominately tangential structure in the slow-rise phase, but displays greater radial features during/after the eruption. The polar-swirl activation initially shows a strong radial contribution, which diminishes as more tangential structures appear during/after the activation. Our results demonstrate the successful application of the spatial RHT to prominences, leading to the classification of individual prominences and an insight into their dynamics.