Initial formation of an “impulsive” coronal mass ejection

Abstract

An “impulsive” coronal mass ejection (CME) observed on August 24, 2014 is analyzed using ultraviolet images obtained in the SDO/AIA 193, 304, 1600, and 1700 Å channels and Hα (6562.8 Å) data obtained with the EI Teide and Big Bear telescopes. The formation of this impulsive CME was related to a magnetic tube (rope) moving with a velocity of ≈35 km/s and containing plasma that was cooler than the photospheric material. Moving in the corona, the magnetic tube collides with a quasi-stationary coronal magnetic rope, with its two bases rooted in the photosphere. This interaction results in the formation of the CME, with the surface of the coronal magnetic rope becoming the CME frontal structure. According to SDO/HMI data, no enhancements or changes in magnetic flux were detected in the vicinity of the CME bases during its formation. This may support the hypothesis that the magnetic tube starts its motion from layers in the vicinity of the temperature minimum.