The configuration and failed eruption of a complex magnetic flux rope above a<i>δ</i>sunspot region

Aims. We aim to investigate the configuration of a complex flux rope above δ sunspot region in National Oceanic and Atmospheric Administration AR 11515 its eruptive expansion during confined M5.3-class flare. Methods. studied formation using continuum intensity images photospheric vector magnetograms provided by Helioseismic Magnetic Imager on-board Solar Dynamics Observatory (SDO). employed extreme-ultraviolet ultraviolet Imaging Assembly SDO hard X-ray emission recorded Reuven Ramaty High-Energy Spectroscopic details. The coronal magnetic field is extrapolated from nonlinear force free (NLFFF) method, based on which identified through calculating twist number T w squashing factor Q . searched null point via modified Powell hybrid method. Results. collision between two newly emerged spot groups form sunspot. A bald patch (BP) forms at location one umbra penumbra, structure identified. has multilayer configuration, with compact end other bifurcating into different branches. It non-uniform profile, decreases core boundary. outmost layer merely sheared. located rope. process consists precursor flarings v -shaped structure, rise filament, brightening below corresponding well topological structures deduced NLFFF, including higher point, rope, BP hyperbolic tube (HFT) Two sets post-flare loops three flare ribbons further support bifurcation Conclusions. Combining observations extrapolation, we conclude that reconnection, occurs weakens overlying confinement allow rise, fitting breakout model. main phase may occur or HFT, facilitates rising. results suggest presents an environment prone configurations work together produce activities.