Multi-wavelength Observation of a Failed Eruption from a Helical Kink-unstable Prominence

Abstract

Multi-wavelength observations of prominence eruptions provide an opportunity to uncover the physical mechanism of the triggering and the evolution process of the eruption. In this paper, we investigated an erupting prominence on October 14, 2012, recorded in Hα, EUV, and X-ray wavelengths. The process of the eruption gives evidences on the existence of a helical magnetic structure showing the twist converting to writhe. The estimated twist is ∼ 6π (3 turns), exceeding the threshold of the kink instability. The rising plasma reached a high speed at 228 km s −1 , followed by a sudden rapid acceleration at 2715 m s −2 , and synchronous with a solar flare. Co-spatial cusp shaped structures were observed in both AIA 131 Å and 94 Å images, signifying the location of the magnetic reconnection. The erupted flux rope finally undergone a deceleration with a maximum value of 391 m s −2 , which is larger than the free-fall acceleration on the Sun (273 m s −2 ), suggesting that the eruption finally failed, possibly due to an inward magnetic tension force.