Source Region and Launch Characteristics of Magnetic-arch-blowout Solar Coronal Mass Ejections Driven by Homologous Compact-flare Blowout Jets

TL;DR

This study analyzes four homologous CMEs driven by blowout jets from active region 11515, revealing their source regions, magnetic configurations, and flux changes that likely triggered the eruptions, with implications for understanding solar activity.

Contribution

It provides detailed analysis of the source regions and magnetic conditions of homologous CMEs driven by blowout jets, highlighting flux changes as eruption triggers.

Findings

All CMEs were wide with speeds 300-500 km/s.

Eruptions originated near flux rope footpoints with flux emergence and cancellation.

Homologous eruptions linked to large-scale loop systems connecting active region to remote regions.

Abstract

We study the formation of four coronal mass ejections (CMEs) originating from homologous blowout jets. All of the blowout jets originated from NOAA active region (AR) 11515 on 2012 July 2, within a time interval of $\approx$14 hr. All of the CMEs were wide (angular widths $\approx$95$-$150$^\circ$), and propagated with speeds ranging between $\approx$300$-$500 km s$^{-1}$ in LASCO coronagraph images. Observations at various EUV wavelengths in Solar Dynamics Observatory/Atmospheric Imaging Assembly images reveal that in all the cases, the source region of the jets lies at the boundary of the leading part of AR 11515 that hosts a small filament before each event. Coronal magnetic field modeling based on nonlinear force free extrapolations indicate that in each case the filament is contained inside of a magnetic flux rope that remains constrained by overlying compact loops. The southern footpoint of each filament is rooted in the negative polarity region where the eruption onsets occur. This negative-polarity region undergoes continuous flux changes, including emergence and cancellation with opposite polarity in the vicinity of the flux rope, and the EUV images reveal brightening episodes near the filament's southeastern footpoint before each eruption. Therefore, these flux changes are likely the cause of the subsequent eruptions. These four homologous eruptions originate near adjacent feet of two large-scale loop systems connecting from that positive-polarity part of the AR to two remote negative-polarity regions, and result in large-scale consequences in the solar corona.