Eruption and Interplanetary Evolution of a Stealth Streamer-blowout CME Observed at ~0.5 AU 

Abstract

<p>The orbit of the Parker Solar Probe (PSP) during the 5th encounter with the Sun presented an opportunity for a multi-observation analysis including the observations of Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI) coronagraphs and Large Angle and Spectrometric Coronagraph (LASCO) coronagraphs. Streamer-blowout coronal mass ejections (SBO-CMEs) are the dominant CME population during solar minimum. With the aid of extrapolated coronal fields and remote observations of the off-limb low corona, we study the initiation of an SBO-CME preceded by consecutive CME eruptions following a multi-stage sympathetic breakout scenario. The suprathermal electron pitch-angle distributions (PADs) and magnetic field observations by PSP suggest that draping of interplanetary magnetic field lines about the CME caused a curvature in the adjacent heliospheric current sheet, initiated magnetic reconnection with the CME flux rope about ~45 hours before it encountered PSP, and eroded ~38% of its initial poloidal magnetic flux at ~0.5 AU. This study covering inner heliospheric observation and analysis of SBO-CME magnetic content provides important implications for the origin of twisted magnetic field lines in SBO-CME flux ropes as the flux rope is not perturbed much by the interplanetary propagation. Also, the multi-spacecraft observations allowed us to estimate the distances where reconnection between the flux rope and its surroundings may be initiated. </p>