Formation and Evolution of Transient Prominence Bubbles Driven by Erupting Minifilaments

Abstract

Abstract Prominence bubbles, the dark arch-shaped voids below quiescent prominences, are generally believed to be caused by the interaction between the prominences and the slowly emerging or quasi-stable underlying magnetic loops. However, this scenario could not explain some short-lived bubbles with extremely dynamic properties of evolution. Based on high-resolution Hα observations, here we propose that bubbles should be classified into two categories according to their dynamic properties: quasi-steady Type-I bubbles and transient Type-II bubbles. Type-I bubbles could remain relatively stable and last for several hours, indicating the existence of a quasi-stable magnetic topology, while Type-II bubbles grow and collapse quickly within 1 hr without stability duration, which are usually associated with erupting minifilaments. Analysis of several typical Type-II bubbles from different views, especially including an on-disk event, reveals that Type-II bubbles quickly appear and expand at a velocity of ∼5–25 km s−1 accompanied by an erupting minifilament below. The minifilament’s rising velocity is slightly larger than that of the Type-II bubbles’ boundary, which will lead to the collision with each other in a short time, subsequent collapse of Type-II bubbles, and formation of a large plume into the above prominence. We also speculate that only if the angle between the axis of the erupting minifilament and the line of sight is large enough, the interaction between the erupting minifilament and the overlying prominence could trigger a Type-II bubble with a typical arch-shaped but quickly expanding bright boundary.